EarthSky

Habitable worlds: Better than Earth? Scientists wonder

Paul Scott Anderson — Mon, 26 Oct 2026 13:02:07 +0000

Artist’s illustration of a super-Earth type exoplanet close to its red dwarf star. Some of these worlds might be superhabitable, with the potential for even more diverse kinds of life than on Earth. Are there actually worlds more habitable than Earth? Image via C. Lionel/ University of Liège.

Astronomers use the word habitable to mean a planet whose physical conditions might allow life — any form of life, perhaps microbial life — to exist there.
Are there worlds more habitable than Earth? Some scientists think so.
They wonder if super-Earth planets — larger and more massive than Earth — might be better suited for life than Earth is.

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Are there worlds more habitable than Earth?

Scientists are seeking signs of life elsewhere in the universe. Even the tiniest microbe would be big news! So far, we don’t have conclusive evidence of any form of life on any planet beyond our own. So Earth is our primary model for what might be possible. Our planet is still the only one known to be brimming with life.

We know many rocky planets like Earth exist. Some are larger and more massive than our planet. We call them super-Earths. And we know that some are potentially habitable. Could they be even more habitable than Earth?

Some scientists have been weighing that idea. Nowadays, they are more confident that such worlds might exist, especially since about 2010. The Kepler Space Telescope, for example, launched in 2009 and has demonstrated that Earth-sized and super-Earth-sized planets are extremely common across the Milky Way Galaxy.

Do the most habitable worlds orbit K dwarfs?

Beginning around 2010, astrobiologists — scientists who study the possibility of life beyond Earth — began recognizing that G-type stars like our sun might not be the best places for life. Research around this time highlighted orange dwarfs (K-type stars). They are far more abundant, have significantly longer lifespans (tens of billions of years in contrast to our sun’s 10 billion years) and emit less harmful ultraviolet radiation.

Scientists like René Heller and John Armstrong began challenging the anthropocentric assumption that an Earth twin is the ideal place for life. They formulated the concept of superhabitable worlds: super-Earths with stronger magnetic fields, thicker atmospheres and warmer, more stable climates capable of supporting richer, more diverse ecosystems than Earth.

They teamed up in 2014 to present the hypothesis that smaller, cooler stars might be better for habitable planets. Why? Because they burn through their hydrogen fuel more slowly and brighten more gradually as they age. So they have longer lifespans for life to develop.

Our own sun only has about five billion years left before it turns into a red giant star. But K-type stars can live for tens of billions of years. What kind of life could develop on planets in that length of time?

Armstrong, a professor at Weber State University in Utah, recently asked in the comments section of an astrobiology seminar on YouTube:

Shouldn’t there be planets more habitable than Earth?

What would these worlds be like?

Natalie Wolchover wrote about the fascinating possibility of superhabitable worlds for The New York Times on October 13, 2026. She pointed out that carbon-based life — like on Earth — could last longer and be even more diverse on such worlds than on Earth. But what might these planets be like?

The researchers say that typically they would be 20-30% larger than Earth and twice as massive. Hence, a super-Earth. Like Earth, they’d need water. But such massive rocky planets would have stronger gravity than Earth. They’d have been able to hold on to the ingredients for water as they formed. So they might have thicker atmospheres than Earth. They might have warmer and more stable climates.

Plus, super-Earths likely have iron cores that are larger than Earth’s. Those cores could produce stronger magnetic fields that would protect life even better than Earth’s magnetic field.

But — in the space of our Milky Way Galaxy — do we know of any super-Earths orbiting more benign K-type stars better suited for life than Earth? The answer to that is no.

View larger. | This photo shows photosynthesis in action. The lake seaweed is emitting small trails of oxygen bubbles that can be seen in very still waters. Photosynthesis might be even more robust on planets with K-type stars, experiments show. Image via Rcaravit/ Wikimedia Commons.

Experiments related to super-Earths

As noted in Wolchover’s article, astrobiologist Iva Vilovic at the Leibniz Institute for Astrophysics in Potsdam, Germany, thinks that life could thrive on super-Earths orbiting K-type stars.

She did experiments with garden cress. She simulated the light coming from a K-type star to see if photosynthesis would occur. And surprise! The plants grew even better than they did under regular sunlight on Earth. She told Wolchover:

K-dwarf light is a very, very interesting light source, and it should be considered, if not prioritized, for any type of search for extraterrestrial life, in my opinion.

The idea of a planet even more biologically diverse than Earth might be hard to imagine. On Earth, the tropics are some of the most biodiverse areas on the planet. But what if an entire planet was like that?

Consider that the light from the K-type star could reach to the bottom of a shallow ocean. This could help fuel an amazingly diverse marine ecosystem, including on any islands that might exist.

Is Earth only marginally habitable?

The seemingly endless kinds of life on Earth are breathtaking. But many scientists consider Earth to be only marginally habitable. If our planet were just 2% closer to the sun, for example, it probably wouldn’t have as much — if any — surface water.

So did we just get lucky?

René Heller, at the Max Planck Institute for Solar System Research in Germany, thinks that maybe we shouldn’t be so focused on finding Earth’s “twin.” He said:

It occurred to me that currently, humanity is looking for Earthlike planets with the same anthropocentric bias. Of course, Earth is special to us. But from a universal perspective, why should Earth be a reference?

He also wonders about there being “someone to talk to,” saying:

Although I am not, at least in my everyday life, a very spiritual person, it’s nevertheless something that at least drives me, this question. Could there be someone?

View larger. | A representation of the Tree of Life on Earth, based on the Tree of Life from the BBC. Earth hosts an astonishing variety of life. But could life on some planets be even more diverse? Image via Maytenus23/ Wikimedia Commons.

How can we find worlds more habitable than Earth?

If such worlds do exist, how can we find them? The European Space Agency’s Plato mission is launching in 2027. The space telescope will be able to find potentially habitable planets, including super-Earths orbiting K-type stars. But it will have its limits. Heller said:

We will probably find a few of them, maybe a dozen. But we won’t learn much about them.

But there’s also the James Webb Space Telescope and the Extremely Large Telescope in Chile. Both can find potentially habitable super-Earths. And NASA’s planned Habitable Worlds Observatory — expected to launch sometime in the 2040s — will be able to make more detailed observations.

View larger. | NASA’s Habitable Worlds Observatory, due to launch in the 2040s, will be able to take a much closer look at potentially habitable exoplanets. Image via NASA’s Goddard Space Flight Center Conceptual Image Lab/ Habitable Worlds Observatory.

Bottom line: Some scientists think there are more habitable worlds than Earth out there. What are they like? And how might we find them?

Via The New York Times

Discover the most fascinating facts about all the beings with whom we share Earth

The post Habitable worlds: Better than Earth? Scientists wonder first appeared on EarthSky.

Sun news: The Halloween Storms of 2003!

C. Alex Young — Mon, 26 Oct 2026 10:21:12 +0000

Sun news for October 26, 2026: Big anniversary today! This shows the sun in visible light 23 years ago — from October 19 to 26, 2003. These sunspots were soon to unleash the strongest flares of the Halloween Storms. Image via NASA/ ESA SOHO.

Sun news October 26: The Halloween Storms of 2003!

Today’s top story: Twenty-three years ago, the sun looked a lot like it does now. Solar Cycle 23 was winding down, and few expected fireworks. Suddenly, three monster sunspot regions appeared and unleashed some of the most powerful solar storms of the space age. They’re known today as the Halloween Storms of 2003.

And they started quietly. Around October 18, 2003, sunspot region AR10484 rotated onto the sun’s northeast limb. It grew fast into one of the cycle’s biggest sunspot groups. Next, AR10486 announced itself from behind the sun’s limb with an M9.9 (moderate) flare on October 22. And the next day, it fired an X5.4 (strong) flare with a large coronal mass ejection (CME). It would become the largest sunspot group of Solar Cycle 23. On October 25, a third region, AR10488, began emerging near the disk center.

Then, 23 years ago today — on October 26, 2003 — the sun fired a double shot. AR10486 launched an X1.2 flare, which sent a huge wave through the sun’s corona. That evening, AR10484 answered with its own X1.2. And the biggest blasts were still to come. Follow along this week as we relive the Halloween Storms, day by day!

Past 24 hours on the sun

(11 UTC October 25 – 11 UTC October 26)

Flare activity: Solar activity stayed low over the past day. Observers recorded 10 flares: 4 C-class (common) and 6 B-class (weak).

Strongest flares: Three C1.5 flares tied for the top spot. AR4560 fired one at 19:42 UTC on October 25 and another at 01:34 UTC on October 26. Then AR4551 matched them with a C1.5 at 05:44 UTC on October 26.
Other notable flares: AR4551 also produced a C1.3, peaking at 03:55 UTC on October 26.
Lead flare producer: AR4560 generated 7 of the 10 flares, including 2 C-class events. AR4551 contributed the other 3, also including 2 C-class events.

Sunspot regions: Two numbered sunspot regions sat on the visible disk during the past day, while a third rotated out of view. In addition, observers spotted two regions of emerging flux in the southwest and southeast quadrants. Neither has received a number yet.

AR4560 (beta): This moderately sized region was the period’s most prolific flare producer. It now sits right at the western limb, rotating out of view. So its activity should fade as it disappears around the edge.
AR4551 (beta): This southern hemisphere region produced three flares, including one of the period’s three C1.5 flares. It keeps a simple beta configuration.
AR4557: According to the SIDC, this region has rotated behind the west limb and is no longer visible. Its sunspot group had decayed into plage.

Blasts from the sun? Observers spotted 2 CMEs on October 25. Neither should impact Earth.

The first CME appeared in SOHO LASCO imagery starting at 03:15 UTC on October 25. It likely came from a prominence eruption over the east limb. Analysts estimated its speed at about 360 km/s.
A second, slower CME appeared starting at 05:36 UTC on October 25, at an estimated 275 km/s.
Meanwhile, a CME from October 21 (SIDC CME 733) may still deliver a glancing blow early on October 26. However, forecasters assign this scenario low confidence, and no model runs predict a definite Earth impact.

Past 24 hours in space weather

Solar wind: Solar wind speeds stayed slow, varying between about 330 and 420 km/s. Density ran below average.

Bt, Bz and magnetic coupling: The total interplanetary magnetic field (Bt) stayed weak, at or below 6 nT. Meanwhile, the north-south component (Bz) varied weakly between about +4 and -4 nT, with no significant sustained southward intervals.

Earth’s magnetic field: Geomagnetic activity stayed quiet, with the Kp index ranging from 0 to 2. No geomagnetic storms occurred. Aurora displays stayed limited to the typical high-latitude ovals.

Energetic particles: The greater than 2 MeV electron flux reached high levels, peaking at 2,864 pfu at 18:20 UTC on October 25. Meanwhile, the greater than 10 MeV proton flux remained at background levels. No solar radiation storms occurred.

What’s ahead? Sun–Earth forecast

Flare activity forecast: Forecasters expect very low to low activity through October 28. A slight chance exists for isolated M-class (R1-R2) flares on October 26. However, those odds shrink as AR4560 rotates off the disk. C-class flares remain likely, at 50% or greater per the SIDC.

October 26: Expect very low to low levels, with a slight chance of an M-class flare. As AR4560 rotates beyond the west limb, its geoeffectiveness fades. Meanwhile, AR4551 could produce more low-level C flares.
October 27: Very low to low levels should continue. C-class flares are possible from AR4551 and the two unnumbered emerging regions, if they develop further.
October 28: Activity should stay subdued, at very low to low levels, with no complex regions on the disk.

Geomagnetic activity forecast:

October 26: Expect mostly quiet conditions (Kp 0-2). However, a possible glancing blow from the October 21 CME, plus the possible onset of a coronal hole high-speed stream, could briefly push conditions to unsettled or active levels (Kp 3-4). So aurora watchers at high latitudes should keep an eye out, just in case.
October 27: Quiet conditions (Kp 0-2) should prevail under nominal solar wind.
October 28: Expect quiet conditions (Kp 0-2), with no significant drivers in sight.

Sun news October 27, 2026. Here’s today’s sun – with the most active regions labeled – as of 5 UTC this morning, as seen by the Solar Dynamics Observatory (SDO). Original image, without labels, via NASA SDO. Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky. Armando Caussade posted today’s sun. Why are east and west on the sun reversed?

The sun in recent days

Sun news October 26, 2026. Here’s today’s sun – with the most active regions labeled – as of 1 UTC this morning, as seen by the Solar Dynamics Observatory (SDO). Image via NASA SDO.

Sun news October 25, 2026. Here’s today’s sun – with the most active regions labeled – as of 6 UTC this morning, as seen by the Solar Dynamics Observatory (SDO). Image via NASA SDO.

Sun images from our community

View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured these filtered images on October 26, 2026. Mario wrote: “The sun in hydrogen-alpha, hydrogen-epsilon, helium D3, sodium D2, iron (Fe I) and calcium-H.” Thank you, Mario!

View at EarthSky Community Photos. | Victor Rogus in Sedona, Arizona, captured this filtered image on October 26, 2026. Victor wrote: “Barely visible to us through a 5-inch refractor we see sunspot AR4560 that is about to disappear over the sun’s western limb. Only its remains appear here in this circled location. The sun may soon become spotless.” Thank you, Victor!

View at EarthSky Community Photos. | Jim Militello in Tucson, Arizona, captured this filtered image on October 25, 2026. Jim wrote: “Hydrogen-alpha image of the sun showing active regions, filaments and prominences.” Thank you, Jim!

We sometimes feature sun images obtained using hydrogen-alpha filters. Read why.

Bottom line: Sun news October 24, 2026: On this date in 2003, the sun fired 2 X flares as monster sunspots grew. The 2003 Halloween Storms were just getting started!

Submit your photos here.

View community photos here

The post Sun news: The Halloween Storms of 2003! first appeared on EarthSky.

Visible planets and night sky guide for October and November

Marcy Curran — Mon, 26 Oct 2026 10:15:00 +0000

October 26 and 27 evenings: Moon near Aldebaran and the Pleiades

This evening, the bright waning gibbous moon will lie near the Pleiades star cluster. The brightest star of Taurus the Bull, Aldebaran, will shine nearby. They’ll be visible through dawn the next morning. Chart via EarthSky.

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view — and time — from your location, try Stellarium Online.

October 27 evening: Binocular view of the moon and Pleiades

Here’s a binocular view of the waning gibbous moon in the late evening of October 27, appearing close to the stars of the Pleiades star cluster. They’ll be closest at 2 UTC on October 28 (9 p.m. CDT on October 27). Chart via EarthSky.

Don’t miss the morning sky: Jupiter and Mars are getting closer!

Jupiter — the 2nd-brightest planet — is now high in the east at dawn. Face the sunrise direction and look up. You can’t miss it. Then extend that line from the sunrise point, through Jupiter. You’ll soon come to much-fainter Mars. Jupiter and Mars are drawing closer. Mars will pass 1.2 degrees to the north of Jupiter on November 15. They are so much fun to watch! And will you see Saturn in the west? Saturn reached opposition on October 4. That’s when Earth passed between Saturn and the sun, bringing Saturn opposite the sun in our sky. During its opposition month, Saturn is generally closest and brightest for the year, by late October, Saturn is no longer visible before dawn. That’s because Earth has moved on in orbit around the sun. And so, as the weeks pass, Saturn appears higher and higher in our eastern sky at nightfall and below the horizon by dawn. Chart via EarthSky.

It’s Saturn time!

For the whole Earth, Saturn is putting on one of its best shows of the year. The ringed planet is bright, visible throughout the night and perfectly placed for observing. Saturn reached opposition on October 4, when Earth passed between it and the sun, marking the peak of its visibility for 2026. But the show is far from over! Watch the video above — with host Deborah Byrd — to look ahead to Saturn’s 2026–27 observing season. Watch in the player above, or on YouTube.

Saturn lies in the east in the evening hours of October. Grab a telescope for a chance to see the planet’s iconic rings while it’s still well placed for observing. Chart via EarthSky.

When will you next see Venus?

October 28 evening: Moon near Capella, Aldebaran and Pleiades

In the late evening of October 28, the waning gibbous moon will appear between 2 bright stars, Capella and Aldebaran. The Pleiades star cluster will be nearby. Chart via EarthSky.

October 30 and 31 mornings: Moon near Pollux and Castor

Before dawn on the last 2 mornings of October, the moon, nearing its 3rd quarter phase, will approach Castor and Pollux, the twin stars of Gemini. (Pollux is the brighter of the pair.) On October 31, the moon will shine by the 2 stars. Chart via EarthSky.

November 1 evening: Moon near Pollux and Castor

Late on November 1, look for the twin stars of Gemini, Castor and Pollux, leading the 3rd quarter moon up from the horizon (Pollux is the brighter of the pair.) Chart via EarthSky.

November 1: Watch for the 3rd quarter moon

View at EarthSky Community Photos. | Mandy Daniels captured the third quarter moon in daylight on October 3, 2026, from the UK. Thank you, Mandy! The moment of the 3rd quarter moon will fall at 20:28 UTC on November 1, 2026. That’s 2:28 p.m. Central Standard Time. It’ll rise in the middle of the night and set around midday. Look for it high in the sky before dawn.

Want more? Here are 4 keys to understanding the moon’s phases.

November morning planets: Northern Hemisphere view

The November morning sky — around November 7 — features 3 bright planets that you can see before dawn. The brightest — Venus — is visible just before dawn and follows bright Jupiter and red Mars across the sky as the sun rises. Chart via EarthSky.

Early November evening planet: Northern Hemisphere

The evening sky in early November features 1 bright planet: Golden Saturn will be shining in the east as darkness falls. It’ll be visible until after midnight all month. Chart via EarthSky.

November 2 and 3 mornings: Moon near Jupiter, Mars and Regulus

The waning crescent moon will lie near Jupiter and close to red Mars on the morning of November 2. Below them is the bright star Regulus, the brightest star in Leo the Lion. Then the thick crescent moon will lie close to Regulus on the following morning, November 3. Keep an eye on Mars and Jupiter. They’ll get closer over the next 2 weeks, coming to within almost 2 full-moon widths of each other on the morning of November 15. Chart via EarthSky.

Early November: South and North Taurid meteor shower

View at EarthSky Community Photos. | Eliot Herman captured this image of a Taurid fireball on November 5, 2022, from Arizona. Thank you, Eliot! Taurid meteors consist of 2 streams, the South Taurids and North Taurids. Both streams radiate from the constellation Taurus the Bull, not far from the bright star Aldebaran and the tiny, misty, dipper-shaped Pleiades. Taurus is high in the sky in the middle of the night now. So the hours around midnight are a good time to watch for Taurid meteors and fireballs, as they appear to originate from the constellation Taurus. In October and November, this constellation is highest in the sky in the middle of the night. And Taurid meteors ramble across the sky for weeks; they don’t have a definite peak.

November 5 and 6 mornings: Moon plus Venus and Spica

In the early morning hours of November 5, the waning crescent moon will float high in the east. Brilliant Venus is above the eastern horizon and is next to the star Spica. Spica is the brightest star in Virgo the Maiden. Chart via EarthSky.

November 6 and 7 mornings: Moon near Venus and Spica

On the morning of November 6, the waning crescent moon will float above brilliant Venus. Can you also spot the bright star Spica close to Venus through dawn’s growing light? Then, on the following morning, the slender waning crescent moon forms a tight trio with Venus and Spica. Chart via EarthSky.

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view — and time — from your location, try Stellarium Online.

November 9: New moon

Here’s a view of new moon we don’t often get to see. NOAA’s CCOR-1 coronagraph aboard the GOES-19 spacecraft spotted the moon drifting through its field of view on its way to the August 12, 2026, total solar eclipse. CCOR-1 blocks the sun’s blinding face with an occulting disk so it can watch the faint outer corona for coronal mass ejections. This month, the moment of new moon will fall at 7:02 UTC on November 9, 2026. That’s 1:02 a.m. Central Standard Time in the Americas. New moons rise and set with the sun. Nights around the new moon offer the darkest skies. See EarthSky’s best places to stargaze. Images via NOAA/ GOES.

Want more? Here are 4 keys to understanding the moon’s phases.

November 11 evening: Thin crescent moon

On November 11, the thin waxing crescent moon will float above the western horizon in the bright evening twilight shortly after sunset. Can you spot it before it sets? Chart via EarthSky.

November 12 and 13 evenings: Thin crescent moons glowing with earthshine

Shortly after sunset on November 12 and 13, the waxing crescent moon will glow with earthshine as it floats above the western horizon. Chart via EarthSky.

November 15 to 17 mornings: Jupiter and Mars conjunction

Bright Jupiter and red Mars will shine in the east before sunrise in November. Below them is the brightest star in Leo the Lion, Regulus. Don’t miss them on the mornings of November 15 to 17. On those mornings, Jupiter will lie close to Mars. They’ll be at their closest — a little more than 2 full-moon widths apart — at 3 UTC on November 15. Chart via EarthSky.

November 15 and 16 evenings: Moon near Capricornus

The moon, nearing its first quarter phase, will lie among the stars of Capricornus the Sea-goat on the evenings of November 15 and 16. They’ll set after midnight. Chart via EarthSky.

November 17 overnight: Leonid meteor shower

View at EarthSky Community Photos. | James Reynolds in Leicester, North Carolina, caught this Leonid meteor on November 17, 2020. Thanks, James! In 2026, watch for Leonids after midnight on November 17 through dawn on November 18. The radiant point rises around midnight and is highest in the sky at dawn. So the quarter moon will be setting around the time the radiant rises and won’t interfere with watching for meteors.

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view — and time — from your location, try Stellarium Online.

November 17: 1st quarter moon

View at EarthSky Community Photos. | Asha Prasad captured this image on October 18, 2026, from Minnesota. Asha wrote: “First quarter moon captured on a calm October evening.” Thank you, Asha! This month’s moment of 1st quarter moon will fall at 11:48 UTC on November 17, 2026. That’s 5:48 a.m. Central Standard Time in the Americas. A 1st quarter moon rises around noon your local time and sets around midnight. Watch for a 1st quarter moon high in the sky at sundown.

November 19 and 20 evenings: Moon near Saturn

The waxing gibbous moon will lie near the steady golden light of Saturn on the evenings of November 19 and 20. They’ll set several hours after the middle of the night. Saturn is still well placed for observing this month after its recent opposition, when it was at its biggest and brightest. Chart via EarthSky.

Want more? Here are 4 keys to understanding the moon’s phases.

Mercury reaches greatest elongation from the morning sun

Mercury will reach its widest angle from the sun in the morning sky on November 21. This point in its orbit is called greatest western elongation. From the Northern Hemisphere, look for the little planet in the east shortly before sunrise. It will lie in the brightening twilight about midway between brilliant Venus (with Spica next to it) and the horizon. Because of the steep angle of its orbit with respect to the horizon, Mercury will climb quickly in the bright morning twilight, making it relatively easy to spot for Northern Hemisphere viewers. Chart via EarthSky.

Late November morning planets

On the morning of November 21, as viewed from the Northern Hemisphere, look for brilliant Venus low on the eastern horizon and Mercury even lower. Mercury will reach its greatest distance from the sun on November 21. And Venus will reach its greatest brilliancy — its brightest in the morning sky — on November 29. Above them will be the planets Jupiter and Mars. Chart via EarthSky.

Late November evening planets

Around the middle of the night in late November, there will be 3 bright planets in the sky. The brightest — Jupiter — is rising in the east, followed by red Mars. And Saturn is setting in the west. Chart via EarthSky.

November 23 and 24 evenings: Supermoon near Aldebaran and Pleiades

On the evening of November 23, the bright waxing gibbous moon will shine near the brightest star of Taurus the Bull, Aldebaran. Plus, the Pleiades star cluster will be nearby. Can you see the misty star cluster near the bright glow of the moon? Then, the next evening, November 24, the Full Beaver Supermoon shines all night near Aldebaran and the Pleiades. They’ll be visible through dawn the next morning. Chart via EarthSky.

November 25 evening: Moon and a trio of bright stars

As darkness falls on the evening of November 25, the waning gibbous moon — rising in the east — will be surrounded by 3 bright stars, Capella, Aldebaran and Betelgeuse. Chart via EarthSky.

Our charts are mostly set for mid-latitudes in the Northern Hemisphere. To see a precise view — and time — from your location, try Stellarium Online.

November 26 and 27 evenings: Moon near the twin stars

A few hours after sunset on the evenings of November 26 and 27, the waning gibbous moon will float near Castor (the dimmer twin star) and Pollux (the brighter twin star) in Gemini the Twins. You can catch them all night until dawn. Chart via EarthSky.

November 29 and 30 mornings: Moon near Jupiter, Mars and Regulus

The moon approaching its third quarter phase lies high in the east before dawn on the morning of November 29. Jupiter, Mars and the bright star Regulus are nearby. On the following morning, November 30, the moon, Jupiter, Mars and Regulus make an eye-catching tight group in the morning sky. Chart via EarthSky.

October visible planets: Evening

From the Southern Hemisphere, shortly after sunset in the first part of the month, Venus will shine brightly in the west. To its lower right lies the much dimmer Mercury in the bright twilight. The waxing crescent moon will visit Mercury on October 12, and Mercury is also at its greatest distance from the sun that evening. By the middle of the month, Venus has dropped close to the horizon, while Mercury maintains its height. Near the end of the month, Venus has disappeared. Mercury is still present but will appear less bright than it was earlier in October. For those in the Northern Hemisphere, Venus will slip away by mid-month and Mercury will be challenging to spot during this evening apparition. Chart via EarthSky.

Saturn will be shining as a steady golden light in the east during the evening hours of October. It’s the brightest object in that part of the sky, other than the passing moon. It’ll be highest in the sky around the middle of the night and low in the western morning sky before dawn. Saturn reached opposition so it was at its biggest and brightest — when we flew between it and the sun — on October 4. Chart via EarthSky.

October visible planets: Morning

Bright Jupiter will lie in the east before sunrise in October. Above it is red Mars and below it is Regulus, the brightest star in Leo the Lion. By the end of the month, Jupiter and Mars will be closer to each other. Chart via EarthSky.

November morning planets

Shortly before sunrise after November 5, Venus will shine brightly in the east next to the star Spica. By the middle of the month, Venus and Spica will have risen higher in the sky. And Mercury will get easier to see as the month progresses. By the end of November, Venus will have moved farther away from Spica. Chart via EarthSky.

Bright Jupiter will lie high in the east a few hours before sunrise in early November. Mars will be above it with the star Regulus below. By mid-month, Mars will drop below Jupiter. Near the end of November, Mars will leave Jupiter behind and and sink toward Regulus. Chart via EarthSky.

Mercury will reach its greatest elongation from the sun at 0 UTC on November 21, 2026. In early November, from the Northern Hemisphere, Mercury will lie low in the east shortly before sunrise. Brilliant Venus and the star Spica are next to each other and far above Mercury. After the middle of the month, Mercury will have brightened and climbed toward Venus and Spica. By month’s end, Mercury will have begun to descend, and it will slip away by mid-December. Chart via EarthSky.

October stars

If you’re out stargazing on any October evening, look for these stars and constellations in the evening sky.

The house-shaped constellation Cepheus the King lies in the northern sky by the constellation Cassiopeia. Gamma Cephei, or Errai marks the peak of the roof of the house. And Errai is very near Polaris, the North Star.

Find Algol the Demon Star in the constellation Perseus on autumn evenings. And Perseus lies below the easy-to-recognize W-shaped constellation Cassiopeia.

Although the Big Dipper is low on the horizon — or below the horizon — for mid-northern latitudes now, the Little Dipper is high in the northern sky. In fact, the Big Dipper is tough to spot on late October evenings because it rides so low in the north. As always, the 2 outer stars in the Dipper’s bowl point to Polaris, the North Star.

Our charts are mostly set for the northern half of Earth. To see a precise view — and time — from your location, try Stellarium Online.

Have fun exploring the sky!

New to stargazing? Read more: Planisphere: Your friend to find stars and constellations

November stars

If you’re out stargazing on any November evening, look for these stars and constellations in the evening sky.

On November and December evenings, when W-shaped Cassiopeia the Queen rides high in the north, her husband on the sky’s dome, Cepheus the King, does, too. The house-shaped Cepheus lies inside a triangle formed by the Little Dipper, Cassiopeia and Cygnus the Swan (or the Northern Cross).

Find Perseus with the help of the constellation Cassiopeia the Queen. Cassiopeia’s distinctive M or W shape is ascending in the northeast on Northern Hemisphere autumn evenings, with Perseus following. Cassiopeia and Perseus travel together in a great arc around the northern sky. Be sure to look for the star Algol, sometimes called the Ghoul Star or Demon Star. Chart via EarthSky.

Here’s an easy way to use the prominent M or W shape of Cassiopeia to locate the Double Cluster in Perseus.

Our charts are mostly set for the northern half of Earth. To see a precise view — and time — from your location, try Stellarium Online.

Have fun exploring the sky!

New to stargazing? Read more: Planisphere: Your friend to find stars and constellations

Sky dome map for visible planets and night sky

Here is the sky dome view for October 2026. It shows what is above the horizon at mid-evening for mid-northern latitudes. The view may vary depending on your location. Image via Guy Ottewell’s 2026 Astronomical Calendar.

Here is the sky dome view for November 2026. It shows what is above the horizon at mid-evening for mid-northern latitudes. The view may vary depending on your location. Image via Guy Ottewell’s 2026 Astronomical Calendar.

Heliocentric solar system visible planets and more

Heliocentric view of solar system, October 2026. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission. Plus Guy Ottewell explains heliocentric charts here.

Heliocentric view of solar system, November 2026. Chart via Guy Ottewell’s 2026 Astronomical Calendar. Used with permission. Plus Guy Ottewell explains heliocentric charts here.

Some resources to enjoy

For more videos of great night sky events, visit EarthSky’s YouTube page.

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Visit EarthSky’s Best Places to Stargaze to find a dark-sky location near you.

Post your own night sky photos at EarthSky Community Photos.

Visit Stellarium-Web.org for precise views from your location.

Visible planets and night sky guide. This evening, look for the thick, bright, waning gibbous moon near the Pleiades star cluster and the brightest star of Taurus the Bull, Aldebaran.

The post Visible planets and night sky guide for October and November first appeared on EarthSky.

How to understand moon phases: 4 tips!

Deborah Byrd — Sun, 25 Oct 2026 13:30:00 +0000

As seen from the north side of the moon’s orbital plane, the Earth rotates or spins counterclockwise. And the moon revolves counterclockwise around Earth. As seen from Earth’s surface, this means Earth spins toward the east (the sunrise direction). And the moon moves toward the east across our sky from day to day. Now add in the sun, and you’ll be ready to understand moon phases. Not to scale. Image via NASA/ Wikimedia Commons.

Like Earth, the sun always illuminates half of the moon. So the moon has a day side. As the moon orbits around Earth once each month, we see varying fractions of its day side: the changing phases of the moon. How can you understand moon phases? Look below for four tips. They’ve helped many people learn to see the moon in a whole new way!

Tip #1. When you see the moon, think about the sun

After all, it’s the sun that’s illuminating and creating the day side of the moon. So moon phases depend on where the moon and sun are in space.

But don’t take our word for it. Go outside. No matter what phase of the moon you see in your sky, think about where the sun is. It’ll help you begin to understand why the moon you see is in that particular phase

Tip #2. The moon rises east and sets west, every day.

It has to. The rising and setting of all celestial objects is due to Earth’s continuous daily spin toward the east under the sky.

So, for example, when you see a thin crescent moon in the west after sunset, it’s not a rising moon. It’s a setting moon. Earth is always carrying you — on your special spot upon the world — toward the east, or toward the sunrise direction. So that crescent moon in the west after sunset must have risen earlier in the morning. It rose soon after the sun and followed the sun across the sky all day, lost in its glare.

Tip #3. One month = one orbit of the moon

Although the moon rises in the east and sets in the west each day (due to Earth’s spin), it’s also moving on the sky’s dome each day due to its own motion in orbit around Earth.

This is a slower, less noticeable motion of the moon. And it’s a motion in front of the fixed stars. So, if you just glance at the moon one evening — and see it again a few hours later — you might notice it has moved westward. That noticeable westward motion is caused by Earth’s spin toward the east.

You can detect the moon’s motion in orbit, too. The moon moves in orbit toward the east (the sunrise direction), the same direction Earth spins. The moon’s orbital motion is less noticeable than its apparent motion caused by the spinning Earth. It’s easiest to catch the moon’s motion in orbit from one day to the next.

And — if you’re looking for the moon’s eastward motion in orbit from one day to the next — it’s easiest if you watch at the same time each day or night.

From Earth, the moon appears to be moving on the inside of a circle of 360 degrees. And the moon takes about a month to orbit Earth. So the moon moves — with respect to the fixed stars — by about 12 to 13 degrees each day on the dome of Earth’s sky.

Tip #4. The moon’s moves in orbit toward the east.

Each day, the moon moves another 12 to 13 degrees toward the east on the sky’s dome. That means — here’s an important key — Earth has to rotate a little more time each day, to bring you around to where the moon is in space.

So the moon rises, on average, about 50 minutes later each day.

The later and later rising times of the moon cause our companion world to appear in a different part of the sky at each nightfall for the two weeks between new and full moon. Then, in the two weeks after full moon, you’ll find the moon rising later and later at night.

And when the moon appears in a different part of the sky to us on Earth’s surface, it’s also in a different part of the sky with respect to the sun. So you see varying fractions of the moon’s day side. Voila! Moon phases!

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More details on individual moon phases at the links below

Follow the links to learn more about the various phases of the moon.

New moon
Waxing crescent
First quarter
Waxing gibbous
Full moon
Waning gibbous
Last quarter
Waning crescent

Moon phases from the EarthSky Community

View at EarthSky Community Photos. | Brandi Mullins in Martinsville, Virginia, shared this composite image on October 12, 2023. Brandi wrote: “Phases of the moon from all my pictures I took over the last month combined into one photograph.” Thank you, Brandi!

View at EarthSky Community Photos. | Mandy Daniels of the UK submitted this composite image in 2025. She wrote: “This collage of images of the moon has been assembled from photographs taken daily from March 29 to April 12. I decided to include the solar eclipse photo as the moon is present, even though we only see the outline of a small section of its perimeter where it bites into the sun. So it represents the 0% phase of our moon and allows a pleasing rectangular aspect ratio for the completed art.” Thank you, Mandy. Read more about this image here.

View at EarthSky Community Photos. | Meiying Lee submitted this composite image of moon phases in 2021. Meiying wrote: “The photos of the moon were taken from August 15 through September 10. On September 11, typhoon #14 Chanthu began to hit Taiwan and interrupted the progress. A friend Bob in Phoenix, Arizona, agreed to complete the last 3 moon-phase photographs that ended on September 13. Through the cooperation of Taiwan and USA, the month-long moon phases documentation finally completes.” Thank you, Meiying and Bob! Read more about this image here.

Bottom line: The moon is a world in space just as Earth is and half of it is always illuminated by the sun. As the moon orbits Earth, we on Earth’s surface see varying fractions of its lighted face, or day side. These are the changing phases of the moon. Four tips to understanding moon phases, here.

Here are the names of all the full moons

Visit Sunrise Sunset Calendars to make your custom moon phases, moonrise-moonset and sunrise-sunset calendars

The post How to understand moon phases: 4 tips! first appeared on EarthSky.

Hunter’s Moon falls on October 25-26, with Saturn nearby

Deborah Byrd — Sun, 25 Oct 2026 12:00:00 +0000

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When and where to look in 2026: For those of us in the Northern Hemisphere, the bright, round Hunter’s Moon — the full moon following the Harvest Moon — rises in the east around sunset on October 25. And be sure to watch for the nearly round moon on the nights before and after that, too. You’ll notice a bright steady light not far from the moon. That’ll be Saturn.

Crest of the full moon falls at 4:12 UTC on October 26, 2026. That’s 11:12 p.m. CDT on October 25 in central North America.

Characteristics of the Hunter’s Moon: The moon is roundest on the day that it’s full. And, on the day of the full moon, the moon will rise close to the time of sunset. But the nights before and after full moon typically feature a round-looking moon, too. And, like the Harvest Moon, the Hunter’s Moon is characterized by a shorter-than-usual time between successive moonrises for several evenings in a row. So watch the moonrise for a few nights around this full moon. If you’re in the Northern Hemisphere, you’ll notice the full or nearly full moon rising near the time of sunset.

For the Southern Hemisphere, the nights around this full moon feature a longer-than-usual time between successive moonrises. So, for the southern part of the globe, the moon on the nights following full moon will seem to rise late! And it’ll rise in a sky that’s already dark.

On the evening of October 25, as darkness falls, the full Hunter’s Moon will light up the eastern sky. It’ll be up all night, opposite the sun. You’ll spot a steady golden light nearby — Saturn! Chart via EarthSky.

What’s special about a Hunter’s Moon?

A full moon is always opposite the sun in space, and opposite the sun in our sky. So, all full moons rise in the east as the sun sets in the west. And all full moons set in the west around sunrise. They are highest in the sky in the middle of the night.

But all full moons have their own characteristics.

On average, the moon rises about 50 minutes later each day. But when a full moon happens close to the autumn equinox — either a Harvest or a Hunter’s Moon — the moon rises only about 30 to 35 minutes later daily for several days around the time of full moon. The reason is that the ecliptic — the path of the sun, moon, and planets across the sky — makes a relatively narrow angle with the evening horizon in autumn.

So if it’s autumn where you are, you can expect a shorter-than-usual lag time between successive moonrises for several days around the full Hunter’s Moon. Those early evening moonrises make every Hunter’s Moon special.

Meanwhile, if you’re in the Southern Hemisphere — where it’s springtime now — you can expect a longer-than-usual time between moonrises for several nights around the full moon.

A great source of moonrise times is timeanddate.com. Once you get to that page, enter your location to see a table of moonrise and moonset times for the month.

By the way, the Harvest Moon can come either before or after the autumn equinox. It typically falls in September. But when the Harvest Moon happens to fall in October, the Hunter’s Moon — the full moon following the Harvest Moon — will land in early November.

That’ll happen next in 2028.

2026 Harvest and Hunter’s Moons. In autumn, the ecliptic — or path of the sun, moon and planets — makes a narrow angle with respect to the eastern evening horizon. So you might see a bright moon in the east shortly after sunset for several evenings in a row. Chart via EarthSky.

Is a Hunter’s Moon bigger or brighter?

No. The Hunter’s Moon is just an ordinary full moon with a special path across our evening sky. Still, many of us do think the Hunter’s Moon looks bigger … or brighter … and more orange than usual. Why?

It’s because the Hunter’s Moon has a powerful mystique. Many people look for it shortly after sunset around the time of full moon. After sunset around any full moon, the moon will always be near the horizon … because full moons rise at sunset. It’s the location of the moon near the horizon that causes the Hunter’s moon — or any full moon — to look big and orange in color.

Orange moon near the horizon. The orange color of a moon near the horizon is a true physical effect. It stems from the fact that, when you look toward the horizon, you are looking in through a greater thickness of Earth’s atmosphere than when you gaze overhead. The atmosphere scatters blue light. That’s why the day sky looks blue. The greater thickness of atmosphere in the direction of a horizon scatters blue light most effectively, but it lets red light pass through to your eyes. So any full moon near the horizon takes on a yellow or orange or reddish hue.

Big moon near the horizon. The bigger-than-usual size of a moon seen near the horizon is something else entirely. It is a trick that your eyes are playing — an illusion — called the Moon Illusion.

2026 full moon is in Aries

The October full moon lies in front of one of three constellations. Two are in the zodiac, Pisces the Fishes and Aries the Ram. The other is a non-zodiacal constellation, Cetus the Whale.

The October full moon most often falls in Pisces. But it occasionally lands in Aries, as it does this year.

Infrequently, though, the October full moon passes through the large neighboring constellation to their south, Cetus the Whale.

The October 2026 full moon occurs on the overnight of October 25 and lies in the constellation Aries. Chart via EarthSky.

How did the Hunter’s Moon get its name?

There are many stories surrounding the names of the full moons, including the Hunter’s Moon. From a practical standpoint, the Harvest Moon and the subsequent Hunter’s Moon provided extra light in the evenings for farmers and hunters to finish their tasks.

Every full moon has a slew of nicknames tied to months of the year. But some full moon names, such as the Harvest and Hunter’s Moons, are tied to the seasons.

In North America, the Harvest Moon was a time when the bright moon meant farmers could stay out later working in their fields and gathering in their crops before the first freeze. After the harvest, farmers would turn to hunting deer and other game to bolster their food stores before winter. The bright light of the full moon and almost full moons would let them hunt into the evening hours. So, we call it a Hunter’s Moon.

Who named the Harvest and Hunter’s Moons? Those names probably sprang to the lips of farmers and hunters throughout the Northern Hemisphere, on autumn evenings at times of the full moon.

Bottom line: The 2026 October full moon is the Hunter’s Moon. It falls around October 25-26. It’s near the planet Saturn and in front of the constellation Aries the Ram.

The post Hunter’s Moon falls on October 25-26, with Saturn nearby first appeared on EarthSky.

Pentagon UAP files part 7: Silent black triangles

Paul Scott Anderson — Sun, 25 Oct 2026 11:28:00 +0000

View larger/full image. | Artist’s digital recreation of a June 2026 UAP incident involving a so-called black triangle. It’s part of the new Pentagon UAP files release, batch 7. Image via DoD.

The U.S. Pentagon released the 7th batch of its UAP files on October 23, 2026.
This Pentagon UAP files release contains 28 new files altogether, and all are PDF documents.
The release is part of a continuing rollout of formerly classified files, every couple or few weeks. So far, there’s still been no “smoking gun” to show that alien craft are visiting Earth. But the files are interesting!

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7th batch of Pentagon UAP files

The U.S. Pentagon released its 1st batch of declassified UAP/UFO materials on May 8, 2026. And now it has just made public batch 7. There are 28 new files in batch 7, all of which are PDF documents (some with images). There are no video, audio or separate image files this time around.

Some of the documents date back to the 1940s, 1950s and 1960s, but others are from this year.

And as usual, Sean Parnell, Assistant to the Secretary of Defense for Public Affairs and Chief Pentagon Spokesman, said in a statement:

Today, the Department of War is publishing the seventh release of declassified and historical Unidentified Anomalous Phenomena (UAP) files as part of the Presidential Unsealing and Reporting System for UAP Encounters (PURSUE). The collection continues to be housed on WAR.GOV/UFO, and the Department will release additional files on a rolling basis.

The Department of War and our agency partners are actively working on the next release of UAP files. The seventh release of UAP files is available now on WAR.GOV/UFO.

For context, the government released a 2nd batch on May 22, a 3rd batch on June 12, the 4th batch on July 10, the 5th batch on August 7 and the 6th batch of the Pentagon UAP files on September 18, all in 2026.

As has been the pattern for these releases, they are a mixed bag of old and previously known material, and newer material. Do the releases prove aliens exist, or that alien craft are visiting Earth? No. Not so far.

The @DeptofWar has released the seventh tranche of records, reinforcing our commitment under PURSUE to increase transparency by responsibly releasing information. To view Release 7: https://t.co/XtJxoryXtt
— All-domain Anomaly Resolution Office (@DoW_AARO) October 23, 2026

View larger. | The 1st page of the AARO memo regarding the June 2026 triangle report. Image via DoD.

Triangular craft over military bases

Black triangular-shaped craft are common in UAP lore, going back several decades, with sporadic records tracing back to the 1950s and 1960s, before exploding into mainstream UFO lore in the 1980s and 1990s.

They have been described as being silent and capable of incredibly fast acceleration. And in many cases, bright lights are reported at each corner of the triangle, with, at times, a pulsing red light on the underside and in the center.

The report from June 2026 is detailed here and here. The reported object was much smaller than many older reports, but intriguing nonetheless. The U.S. All-domain Anomaly Resolution Office (AARO) — a speciallized office within the U.S. Department of Defense, responsible for investigating analyzing and documenting reports of UAP (UFOs) — and the FBI both investigated it. The first description says:

This document is a memorandum for record documenting an AARO witness debrief concerning reported unidentified anomalous phenomena (UAP) observations at a sensitive national security site in the western United States over two days in 2026. AARO considers this incident to warrant further investigation due to the close alignment of the phenomenon’s reported morphological features and kinematic profiles with those of other reported incidents in the western United States region. The memorandum records an interview with two Federal Special Agents and incorporates a corroborating account from a third official positioned at a separate observation post.

The witnesses described the object as triangular, matte black, 13-15 feet (4-5 meters) wide, 6-9 feet (2-3 m) long and 1-2 feet (.3-.6 m) thick. It climbed about 200-300 feet (60-90 m) above the local ridge line and then suddenly stopped and hovered for 20 seconds.

Then, it went into a high-speed horizontal flight. And again, there was reportedly no engine roar, rotor hum or any other noise. The AARO memo said:

Absolute acoustic silence persisted throughout the high-velocity phase. No impact signature, smoke, dust or physical disturbance was observed. A ground survey of the canyon drainage conducted the following morning located no wreckage, ground scarring, or vegetation damage.

BREAKING- White House releases latest tranche of UFO/ UAP FILES.

Pentagon/FBI documents detail military personnel’s encounters with a black triangular craft flying over sensitive military sites, pentagon says it cannot explain the way the crafts maneuvered as they did pic.twitter.com/8HHFIjayvy
— Joe Khalil (@JoeKhalilTV) October 23, 2026

Cylindrical objects in Europe and Middle East

In addition, cylinder-shaped objects have also been reported many times over the decades.

For example, the new release of Pentagon UAP files contains reports of cylindrical or elliptical objects from Sweden (December 17, 1953), Saudi Arabia (January 18, 1957) and elsewhere.

Federal agents encountered a large, triangular aircraft earlier this year that zoomed through the sky from a standstill while making no noise or giving off any exhaust, according to new documents released by the Pentagon. https://t.co/tBXZmpoe7C pic.twitter.com/kKSqnGpntx
— CBS Evening News with Tony Dokoupil (@CBSEveningNews) October 24, 2026

NASA guidance for handling unidentified craft

Also included is interagency guidance from NASA about how to handle unidentified craft — or pieces thereof — that crashed. Why? Because this was during the space race, when the United States and the Soviet Union were placing satellites into orbit, and procedures existed for recovering American and Soviet technology.

The guidance, however, also included a third category for technology that authorities could not identify or classify.

View larger. | Witness sketch from one of the BAASS cases on November 2, 2009. Image via DoD.

Bigelow Aerospace Advanced Space Studies

The new batch includes progress reports from Bigelow Aerospace Advanced Space Studies (BAASS). Robert Bigelow, who founded Bigelow Aerospace, also set up BAASS as a subsidiary to study futuristic technology and UAP. BAASS reported to the Defense Intelligence Agency (DIA).

In addition, BAASS was the sole recipient of a multi-million-dollar government contract (initially $10 million) awarded by the DIA in 2008 to manage the Advanced Aerospace Weapon System Applications Program (AAWSAP).

The monthly reports are here, here, here, here, here and here.

Bottom line: The U.S. Pentagon released its 7th batch of UAP files on October 23, 2026. The documents include reports of silent black triangle craft and more.

Read and watch more:

Document files can be seen and downloaded here

Department of War Publishes Seventh Release of Unidentified Anomalous Phenomena Files on WAR.GOV/UFO

White House releases new UFO documents | Reality Check

New UFO files include details of strange triangular craft: “Absolute acoustic silence”

Latest Pentagon UFO files include reports of triangular craft over military sites

Strange triangular craft reported in new U.S. government UFO release

The post Pentagon UAP files part 7: Silent black triangles first appeared on EarthSky.

Is the Mars Grand Canyon still tectonically active?

Kelly Kizer Whitt — Sun, 25 Oct 2026 11:11:00 +0000

View larger. | Artist’s concept of the view over Valles Marineris, aka the Grand Canyon of Mars. It’s the largest canyon system in the solar system. Researchers recently said that Mars’ Grand Canyon is still tectonically active, though tectonics on Mars are different from those on Earth. Image via Kevin Gill/ Flickr.

Is the Mars Grand Canyon still tectonically active? Scientists say yes

Mars might be smaller than Earth, but its landscape features are overachievers. The red planet is home to both the largest volcano (Olympus Mons) and the largest canyon system (Valles Marineris) in the solar system. Valles Marineris is dubbed the Grand Canyon of Mars. It stretches more than 2,500 miles (4,000 km) long, nine times longer than the Grand Canyon on Earth. It’s also about 20 times wider and five times deeper than Earth’s Grand Canyon. On October 19, 2026, scientists with Columbia University and Imperial College London said Valles Marineris is still tectonically active, billions of years after it formed.

NASA’s InSight lander recently captured seismic data of a marsquake. The new research found the quake occurred 12 to 25 miles (20 to 40 km) beneath Valles Marineris. Rocks slipping along a fault deep in the red planet’s crust triggered the quake. But Mars does not have tectonic plates sliding around on the surface like Earth does. So the quakes today are happening along ancient fault lines on Mars.

The researchers published their peer-reviewed findings in the journal Nature Communications on October 15, 2026.

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Tectonics on Mars versus Earth

Earth’s shaking, rattling and rolling is thanks to the tectonic plates that slide around on the upper mantle. The plates push, pull and slide against each other. Sometimes they get stuck and friction builds up. Eventually the stress snaps in an earthquake.

But quakes on Mars are different. Scientists describe Mars’ crust as similar to an outer shell that behaves like a single, slowly cooling lid. As Mars continues to cool from its early years, the crust shrinks and cracks. This activity forms faults that slip and cause seismic rumbles. And some of these faults, formed billions of years ago, can still slip and shift.

Finding a recent marsquake

On August 25, 2021, the InSight lander detected a quake from its location in Elysium Planitia, on the opposite side of Mars from Valles Marineris. At first, researchers didn’t know if the seismic activity was from a quake. That’s because tremors on Mars can also be from landslides or meteorite impacts.

But then researchers found the quake, named S0976a, had traveled through Mars’ core. Its epicenter was somewhere in the western Valles Marineris region. But its exact location and cause remained obscure.

The new research pinpoints the epicenter at 12 to 25 miles (20 to 40 km) beneath Valles Marineris. The researchers have now been able to learn about not just Mars’ core, but the trigger for the quake. Co-author Doyeon Kim of Imperial College London said:

S0976a has turned out to be an extraordinary event, playing an important role in our understanding of the red planet.

Its waves traveled through the core and helped us investigate the deepest part of Mars, and now they are telling us what happened at the source itself. From a single marsquake, we can learn both about the center of the planet and about an active fault beneath one of its most remarkable landscapes.

The yellow star marks the location of the marsquake that InSight lander detected in 2021. New research pinpointed the location of the quake in the Valles Marineris region of Mars. Image via J. Davis/ NASA/ JPL/ GSFC/ ESA/ DLR/ FuBerlin/ ASU/ ICL.

Grand Canyon of Mars: home to ancient fault and modern stress

The team was able to analyze the seismic waves, including their amplitudes and direction. Then they could reconstruct what must have happened to cause the quake. They said a strike-slip marsquake event was the most likely cause. This happens when two chunks of crust move horizontally past one another along a steep fault with a deep root. In this case, the quake was miles below ground. It created what would be equal to a magnitude 5 quake on Earth.

Lead author Jung-Hun Song of Imperial College London said:

What makes the result compelling is that several completely different types of evidence point in the same direction. The seismic waves tell us that there was a sideways sliding motion on a fault well below the surface, while the geology seen from orbit shows a region crossed by long-lived fault systems.

Song added:

What we see is that this is not just a ‘dead’ fossil landscape, as faults deep beneath the canyon can still slip and generate marsquakes, long after the geological processes that originally formed them have ceased.

Sadly, InSight lander ceased operations in 2022 due to too much dust accumulating on its solar panels. No active lander is currently recording new marsquakes on the surface of Mars. Perhaps we won’t discover the next marsquake until astronauts feel the red planet shake beneath them.

Bottom line: Researchers said the red planet is still tectonically active today. A team found the epicenter and cause of a marsquake at the Grand Canyon of Mars.

Source: Active crustal straining and fault reactivation at Valles Marineris

Via Columbia University

The post Is the Mars Grand Canyon still tectonically active? first appeared on EarthSky.

Olbers’ paradox asks ‘Why is the night sky dark?’

EarthSky Voices — Fri, 23 Oct 2026 10:10:00 +0000

Brian Jackson, Boise State University

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Why is space dark if the universe is filled with stars?

People have been asking why space is dark despite being filled with stars for so long that this question has a special name: Olbers’ paradox.

Astronomers estimate that there are about 200 billion trillion stars in the observable universe. And many of those stars are as bright or even brighter than our sun. So, why isn’t space filled with dazzling light?

I am an astronomer who studies stars and planets — including those outside our solar system — and their motion in space. The study of distant stars and planets helps astronomers like me understand why space is so dark.

You might guess it’s because a lot of the stars in the universe are very far away from Earth. Of course, it is true that the farther away a star is, the less bright it looks. A star 10 times farther away looks 100 times dimmer. But it turns out this isn’t the whole answer.

Imagine a bubble

Pretend, for a moment, that the universe is so old that the light from even the farthest stars has had time to reach Earth. In this imaginary scenario, all of the stars in the universe are not moving at all.

Picture a large bubble with Earth at the center. If the bubble were about 10 light-years across, it would contain about a dozen stars. Of course, at several light-years away, many of those stars would look pretty dim from Earth.

If you keep enlarging the bubble to 1,000 light-years across, then to one million light-years, and then one billion light-years, the farthest stars in the bubble will look even more faint. But there would also be more and more stars inside the bigger and bigger bubble, all of them contributing light. Even though the farthest stars look dimmer and dimmer, there would be a lot more of them, and the whole night sky should look very bright.

It seems I’m back where I started, but I’m actually a little closer to the answer.

Age matters in Olbers’ paradox

In the imaginary bubble illustration, I asked you to imagine that the stars are not moving and that the universe is very old. But the universe is “only” about 13 billion years old.

Even though that’s an amazingly long time in human terms, it’s short in astronomical terms. It’s short enough that the light from stars more distant than about 13 billion light-years hasn’t actually reached Earth yet. And so the actual bubble around Earth that contains all the stars we can see only extends out to about 13 billion light-years from Earth.

There just are not enough stars in the bubble to fill every line of sight. Of course, if you look in some directions in the sky, you can see stars. If you look at other bits of the sky, you can’t see any stars. And that’s because, in those dark spots, the stars that could block your line of sight are so far away their light hasn’t reached Earth yet. As time passes, light from these more and more distant stars will have time to reach us.

The Doppler shift and Olbers’ paradox

You might ask whether the night sky will eventually light up completely. But that brings me back to the other thing I told you to imagine: that all of the stars are not moving. The universe is actually expanding, with the most distant galaxies moving away from Earth at nearly the speed of light.

Because the galaxies are moving away so fast, the light from their stars is pushed into colors the human eye can’t see. This effect is the Doppler shift. So, even if it had enough time to reach you, you still couldn’t see the light from the most distant stars with your eyes. And the night sky would not be completely lit up.

If you wait even longer, eventually the stars will all burn out. Stars like the sun last only about 10 billion years. Astronomers hypothesize that in the distant future — a thousand trillion years from now — the universe will go dark, inhabited by only stellar remnants like white dwarfs and black holes.

Even though our night sky isn’t completely filled with stars, we live in a very special time in the universe’s life, when we’re lucky enough to enjoy a rich and complex night sky, filled with light and dark.

Brian Jackson, Associate Professor of Astronomy, Boise State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Olbers’ paradox asks why is space dark if the universe is filled with stars. The answer is that not all of the light from distant stars has reached us yet. Plus, the universe is expanding, so stars’ light gets red-shifted, pushing it into colors where our human eyes can’t see.

The post Olbers’ paradox asks ‘Why is the night sky dark?’ first appeared on EarthSky.

1st photo of Earth from space, 80 years ago

Eleanor Imster — Fri, 23 Oct 2026 10:03:00 +0000

The 1st photo of Earth from space gave us a look at our world’s clouds from above. The image is from October 24, 1946. Image via White Sands Missile Range/ Applied Physics Laboratory/ Wikimedia Commons.

1st photo of Earth from space

On October 24, 1946, scientists launched a V-2 rocket — carrying a 35-mm motion picture camera — to a height 65 miles (105 km) above a New Mexico desert. After a few minutes, the camera dropped back to Earth and was destroyed on impact. But the film survived.

Today, the Kármán line is the widely recognized boundary that marks the edge of space. It’s located at 62 miles (100 km) above Earth’s surface, roughly where Earth’s atmosphere becomes too thin to support traditional aerodynamic flight. According to the Orbital Radar 2025 Launch Database, we’re currently launching into space at a rate of about a launch per day (6-7 launches per week).

But the 1946 first photo of Earth was nothing short of a revelation.

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Reliving the momentous day

Air & Space Magazine tells the story of this major event in space history:

Snapping a new frame every second and a half, the rocket-borne camera climbed straight up, then fell back to Earth minutes later, slamming into the ground at 500 feet per second [152 meters/second]. The camera itself was smashed, but the film, protected in a steel cassette, was unharmed.

Fred Rulli was a 19-year-old enlisted man assigned to the recovery team that drove into the desert to retrieve film from those early V-2 shots. When the scientists found the cassette in good shape, he recalls, ‘They were ecstatic, they were jumping up and down like kids.’ Later, back at the launch site, ‘when they first projected [the photos] onto the screen, the scientists just went nuts.’

Before 1946, the highest pictures ever taken of the Earth’s surface were from the Explorer II balloon, which had ascended 13.7 miles [22 km] in 1935, high enough to discern the curvature of the Earth. The V-2 cameras reached more than five times that altitude, where they clearly showed the planet set against the blackness of space. When the movie frames were stitched together, Clyde Holliday, the engineer who developed the camera, wrote in National Geographic in 1950 that the V-2 photos showed for the first time ‘how our Earth would look to visitors from another planet coming in on a space ship.’

Another early image from space

Scientists quickly got better at taking Earth’s picture. Here’s a still frame from about 6 months later, taken from V-2 #21, launched on March 7, 1947. This picture is from 101 miles (163 km) up. The dark area on Earth at upper left is the Gulf of California. Image via White Sands Missile Range/ Naval Research Laboratory/ Wikimedia Commons.

See a panorama of Earth from 1948 here

See videos and read the rest of the story from Air & Space.

Bottom line: On October 24, 1946, a movie camera on board a V-2 rocket captured the first photo of Earth from outer space. We’ve come a long way since then!

The post 1st photo of Earth from space, 80 years ago first appeared on EarthSky.

Why does anything exist? New theory emerges

Kelly Kizer Whitt — Thu, 22 Oct 2026 11:28:00 +0000

Why does anything exist? Physicists are puzzled that matter and antimatter didn’t annihilate each other soon after the Big Bang. Instead, we have a universe filled with matter, such as stars, planets, people and even the Crab Nebula (above). This image is from the Hubble Space Telescope with data from 1999 and 2000. Image via NASA/ ESA/ J. Hester and A. Loll/ Wikimedia Commons.

Why does anything exist?

Why does anything exist? And why is there something instead of nothing? The prevailing theory of how the universe began is the Big Bang theory. It states that some 13.8 billion years ago, a burst of growth created matter, space and time. And the Big Bang created not only matter, but antimatter.

Matter and antimatter destroy each other when they meet, releasing energy. If the early universe contained equal amounts of both, they should have wiped each other out, leaving behind a universe filled with energy but no stars, planets or people.

But on October 20, 2026, physicists from the University of Southampton and the Indian Institute of Technology Kanpur said they have a new theory to why everything — including us — exists. They said an often-forgotten particle, the decoupled heavy neutrino, might explain how matter dominated in the early universe.

Co-author Rishav Roshan from the University of Southampton said:

This decoupled heavy neutrino has long been dismissed as an irrelevant background detail in particle physics.

However, it decays incredibly slowly. As the cosmos cooled after the Big Bang, the particle lived long enough that it temporarily took over the energy density of the universe and triggered a matter-dominated period.

The researchers published their peer-reviewed paper in the journal Physical Review Letters on September 8, 2026.

What is a decoupled heavy neutrino?

Neutrinos are tiny subatomic particles with no electric charge and almost no mass. They rarely interact with other matter. Trillions of them pass through your body every second without you noticing. Scientists sometimes call them ghost particles because they are so difficult to detect.

A decoupled heavy neutrino is a theoretical particle that’s incredibly massive with a slow decay. It’s called right-handed because its quantum spin aligns with its direction of motion. It would interact only weakly with other particles, so it could have survived for a long time in the early universe.

And because this particle would have lasted longer than other particles, it could have taken over the energy density of the cooling early universe. This would have allowed it to shift the balance to a matter-dominated universe.

Let’s go back to the beginning

In the moments after the Big Bang, the universe was extremely hot and dense. As it expanded, it cooled, allowing particles to interact and gradually form the building blocks of the universe we know today.

The researchers propose that the heavy neutrino could have lived long enough to temporarily dominate the universe’s energy. This would have changed how quickly the universe expanded and how its temperature evolved.

Roshan said:

The decoupled neutrino shifted the temperature in the early universe at which fundamental particles — like electrons and other leptons — interacted with their antiparticles with the help of Standard Model Higgs boson.

This temperature acts like a switch that shapes how the matter-antimatter imbalance was built up.

A new look at the earliest universe

The researchers said the decoupled heavy neutrino could have profoundly altered the universe’s expansion history. Besides matter and antimatter interactions, they said these special neutrinos also could have had an impact on the production of dark matter and the generation of primordial gravitational waves.

Co-author Sudipta Show from the Indian Institute of Technology Kanpur said:

It offers us a new explanation for how matter won.

The dramatic shift in the early expansion of the cosmos leaves distinct but detectable imprints of changes, for example on primordial gravitational waves.

These gravitational wave signatures open up new avenues for us to unravel the evolution of the early universe after the Big Bang.

So does this answer the question of why does anything exist? For now, it’s an intriguing theory but not a definitive answer. But it might bring us a step closer to understanding why the universe contains something rather than nothing.

Bottom line: Why does anything exist? A new theory by physicists suggests a forgotten particle, the decoupled heavy neutrino, might have shifted the balance between matter and antimatter.

Source: Delayed Charged Lepton Yukawa Equilibration in Minimal Seesaw

Via University of Southampton

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The post Why does anything exist? New theory emerges first appeared on EarthSky.