June solstice in 2026

When is it? In 2026, the solstice moment falls at 8:25 UTC (3:25 a.m. CDT) on June 21.
What is it? At the June solstice, the sun reaches its northernmost point. This point is on the celestial Tropic of Cancer, a parallel around the sky, 23.5 degrees north of the celestial equator. At this solstice, the Northern Hemisphere is most tilted toward the sun, by the maximum angle of 23.5 degrees. Conversely, the south is most tilted away, by the same amount.
What are its main effects? At the June solstice, no matter where you are on Earth, the sun rises and sets farthest north on your horizon. The sun is directly overhead at local noon as viewed from the Tropic of Cancer. Throughout the Northern Hemisphere, the sun is high in the sky and closest to being overhead at local noon. For the Southern Hemisphere, this solstice means the year’s lowest noonday sun.
What about day length? For us in the Northern Hemisphere, the June solstice marks the shortest nights and longest days of the year. For the Southern Hemisphere, it marks the longest nights and shortest days. After this solstice, the sun will begin moving southward in our sky again. So even as we in the Northern Hemisphere celebrate summer, the seeds of winter will already have been sown.

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A 1st quarter moon for this year’s solstice

Stonehenge

For us in the modern world, the solstice is a time to recall the reverence and understanding that early people had for the sky. Some 5,000 years ago, people placed huge stones in a circle on a broad plain in what’s now England and aligned them with the June solstice sunrise.

We might never comprehend the full significance of Stonehenge. But we do know that knowledge of this sort wasn’t limited to just one part of the world. In fact, around the same time Stonehenge was being constructed in England, two great pyramids and then the Sphinx were built on Egyptian sands. If you stood at the Sphinx on the summer solstice and gazed toward the two pyramids, you’d see the sun set exactly between them.

EarthSky’s Will Triggs visited Stonehenge for the sunrise on June 20, 2025. Hear about his experience in the player above, or on YouTube.

What is a solstice?

Ancient cultures knew that the sun’s path across the sky, the length of daylight – and the location of the sunrise and sunset along their horizons – all shifted in a regular way throughout the year.

With this in mind, they built monuments such as the ones at Stonehenge in England and at Machu Picchu in Peru to follow the sun’s yearly progress.

Today, we know that the solstice is caused by Earth’s tilt on its axis and by its orbital motion around the sun.

The Earth doesn’t orbit upright with respect to the plane of our orbit around the sun. Instead, our world is tilted on its axis by 23.5 degrees. Through the year, this tilt causes Earth’s Northern and Southern Hemispheres to trade places in receiving the sun’s light and warmth most directly.

So it’s Earth’s tilt – not our distance from the sun – that causes winter and summer. In fact, our planet is closest to the sun in January, and farthest from the sun in July, during the Northern Hemisphere summer.

Signs of the June solstice in nature

Where should you look? Everywhere.

For all of Earth’s creatures, nothing is so fundamental as the length of the day. After all, the sun is the ultimate source of almost all light and warmth on Earth’s surface.

If you live in the Northern Hemisphere, you might notice the early dawns and late sunsets, and the high arc of the sun across the sky each day. You might see how high the sun appears in the sky at local noon. And, also be sure to look at your noontime shadow. Around the time of the solstice, it’s your shortest noontime shadow of the year.

If you’re a person who’s tuned in to the out-of-doors, you know the peaceful, comforting feeling that accompanies these signs and signals of the year’s longest day.

Is the June solstice the first day of northern summer?

No world body has designated an official day to start each new season, and different schools of thought or traditions define the seasons in different ways.

In meteorology, for example, northern summer begins on June 1. And every schoolchild knows that summer starts when the last school bell of the year rings.

Yet June 21 is perhaps the most widely recognized day upon which summer begins in the Northern Hemisphere and upon which winter begins on the southern half of Earth’s globe. Note that the June solstice can fall on June 20 or 22, too. So, although there’s nothing official about it, it’s a long-held tradition that many recognize those dates as the beginning of the season.

It has been universal among humans to treasure this time of warmth and light.

Why doesn’t the longest day have the hottest weather?

People often ask:

If the June solstice brings the longest day to the Northern Hemisphere, why do we in this hemisphere experience the hottest weather in late July and August?

This effect is called the lag of the seasons. It’s the same reason it’s hotter in mid-afternoon than at noontime. Essentially, Earth just takes a while to warm up after a long winter. Even in June, ice and snow still blanket the ground in some places. The sun has to melt the ice – and warm the oceans – and then we feel the most sweltering summer heat.

Ice and snow have been melting since spring began. Meltwater and rainwater have been percolating down through snow on tops of glaciers.

However, the runoff from glaciers isn’t as great now as it’ll be in another month, even though sunlight is striking the Northern Hemisphere most directly around now.

So wait another month for the hottest weather. It’ll come when the days are already beginning to shorten again, as Earth continues to move in orbit around the sun, bringing us closer to another winter.

And so the cycle continues.

Bottom line: The 2026 June solstice arrives at 8:25 UTC on June 21 (3:25 a.m. CDT). This solstice – the beginning of summer in the Northern Hemisphere – marks the sun’s most northerly point in Earth’s sky.

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Why the hottest weather isn’t on the longest day

The post June solstice 2026: All you need to know first appeared on EarthSky.

• The South Pole-Aitken basin is the largest impact basin on the moon. It’s on the moon’s far side. How did it form?
• Two new studies show that the asteroid that struck the moon, forming the basin, came from the north at a low angle. Rocks from both the lunar crust and mantle were ejected onto the surface.
• Future Artemis astronauts will land in and around the South Pole-Aitken region. The new studies help show what the astronauts can expect to find.

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The South Pole–Aitken basin region is a future landing site

When Artemis astronauts return to the moon in the near future, they’ll land near the lunar south pole. Of the nine possible landing sites, some are within the South Pole-Aitken basin. Others are on or near the rim of the basin, while still others are just outside of it.

For example, the sites Nobile Rim 1, Nobile Rim 2 and Haworth are within the basin (see map below). Malapert Massif is near the basin’s rim. And de Gerlache Rim 2 is outside of the basin. Note that the basin’s boundary is rather obscure and not sharply delineated. So it’s not always clear which proposed landing sites are, technically, within the basin.

Now researchers have published two new peer-reviewed papers about the South Pole-Aitken basin. One is in Science Advances (May 6, 2026). And the other is in JGR Planets (April 23, 2026).

Water ice and sunlight

Here are two reasons this region was chosen for the astronauts: water ice and sunlight. The landing sites closest to the moon’s south pole offer access to water ice, which the astronauts will need as a primary resource. The sites also experience long periods of sunlight.

This giant moon basin is the moon’s oldest and largest impact crater, on the far side of the moon. But how much do we really know about this region? On June 15, 2026, researchers at the Southwest Research Institute (SwRI) in California, said that they have found new details about the South Pole-Aitken basin.

Since it is one of the oldest structures on the moon, the basin provides clues about the early solar system.

William Bottke is the director of the Center for Lunar Origin and Evolution (CLOE) and executive director of SwRI’s Science Directorate in Boulder, Colorado. He is also a co-author of both of the new studies. He said:

The basin offers scientists a rare opportunity to study the moon’s earliest history. The collision struck the lunar surface with such force that it may have excavated material from deep inside the moon, including portions of the lunar mantle [the region just below the moon’s thin crust].

Recreating the impact

To find out more about the future landing location for the Artemis astronauts, the researchers used advanced computer simulations and computer models. They recreated the impact that formed the basin. They found that the impacting asteroid came from the north and hit the moon’s surface at a low angle. That’s why the basin is more elongated in shape than round. (However, scientists said in 2024 that it’s actually slightly rounder than first thought). Shigeru Wakita at Purdue University, lead author of the South-Pole Aitken basin impact study, said:

Our simulation produces the right shape and nature of the impact basin. It also tells us about the projectile that created it and the direction of the impact.

Notably, the analysis suggests that the object that impacted was not just a simple asteroid. The impacting object must have been more complex, with an inner core surrounded by rock. The object’s interior appears to have been differentiated, separated into distinct compositional layers, more like a small protoplanet than a plain rock. Protoplanets are like “baby planets,” smaller objects forming from the accumulation of material in the early solar system. Many would eventually grow to become actual planets, like our own Earth.

When the impactor hit the moon, it created a deep, uneven cavity. The rock in the middle of the basin melted, and material from both the moon’s mantle and crust were thrown out into space.

Ejecta in the basin

The researchers also wanted to know how the ejecta from the impact was distributed in and around the basin. To do this, they compared high-resolution gravity data with models that include both crustal and mantle material. The result was that the basin likely contains a substantial amount of rock from the moon’s mantle. Those rocks are also mixed into the ejecta blanket – the rocky debris – surrounding the basin.

Also, there were smaller secondary impacts that brought some of those rocks to the surface. That is treasure for the future Artemis astronauts who will land there. Gabriel Gowman at the University of Arizona, lead author of the gravity-based study, said:

The precise distribution of mantle material has been a big unknown. Our models indicate that the [South-Pole Aitken basin] impact ejected enough deep material to form a significant deposit that should still be accessible today. Most importantly, some of that material at a trace level may exist in regions being considered for the Artemis landings.

Lots of mantle ejecta for astronauts to explore

Scientists had thought that the deepest part of the ejecta might be far away from the proposed landing sites in the area. But the new studies show this might not be the case. Some of the deposits could extend closer to the south polar region, including the landing sites. That’s good news for the astronauts being able to sample some of those deposits.

In 2019, scientists said they found evidence for an unusually dense mass beneath the South Pole-Aitken basin. The metallic rock is five times larger than the Big Island of Hawaii.

On June 25, 2024, the Chinese Chang’e 6 lunar probe landed in the Apollo basin, a region within the South Pole-Aitken basin. It returned samples to Earth 53 days later.

Bottom line: Two new studies examine the South Pole-Aitken basin on the moon. This region is a future landing site for Artemis astronauts.

Source: A southward differentiated impactor forms the tapered shape of the South Pole–Aitken impact basin on the Moon

Source: Gravity Mapping of Lunar Mantle Material in South Pole-Aitken Basin Ejecta

Via SwRI

Read more: Moon’s largest crater is rounder than 1st thought

Read more: What is the mystery mass on the moon?

The post Artemis missions target South Pole–Aitken basin on the moon first appeared on EarthSky.

Sun news June 21: M flare brightens the June solstice!

Today’s top story: Happy June solstice! And what a way to mark it. The sun continued to simmer at moderate to high levels on the longest day of the year in the Northern Hemisphere. Newly numbered AR4473 stole the spotlight, firing an M2.6 flare at 2:25 UTC this morning. It was the strongest blast of the period. The flare triggered an R1 (minor) radio blackout, briefly disrupting HF communications over the Pacific and eastern Asia. And AR4473 is just getting started. It’s growing as the sun’s rotation carries it further onto the visible disk. Its increasing magnetic complexity makes it the region to watch over the coming days. Earlier in the period, neighboring AR4472 contributed its own M1.0 flare along with a string of C-class events. The solstice also marks a turning point for aurora watchers. Today is the peak of the seasonal disadvantage for aurora viewing in the Northern Hemisphere. The sun-Earth geometry works against displays right now. But from here, the nights gradually grow longer again. And as they do, aurora opportunities will slowly improve. In the Southern Hemisphere, today is the winter solstice, and darkness is at its peak, giving southern aurora chasers their best seasonal window in terms of light.

Past 24 hours of sun news

(11 UTC June 20 – 11 UTC June 21)

Flare activity

Over the past day, solar activity reached moderate levels. In total, the sun fired 12 flares: 2 M-class and 6 C-class events, plus several B-class flares.

• Strongest flare: M2.6 from AR4473 (S07E65) at 2:25 UTC on June 21. It triggered an R1 (minor) radio blackout over the Pacific region.
• Other M-class flare: M1.0 from AR4472 at 14:50 UTC on June 20. It also produced an R1 (minor) radio blackout, affecting the sunlit African and European sectors.
• Notable C-class events: C4.9 from AR4472 at 21:22 UTC on June 20; C1.3 from AR4472 at 23:01 UTC on June 20; C1.1 from AR4472 at 1:01 UTC on June 21; C1.2 from AR4473 at 8:31 UTC on June 21.
• Lead flare producers: AR4473 fired the period’s strongest event, the M2.6. And AR4472 generated the bulk of the overall activity with an M1.0 and multiple C-class flares. Together they drove all the significant activity of the period.

Sunspot regions

The Earth-facing solar disk showed approximately 7 numbered active regions. But the majority remained small and quiet.

AR4473 (beta) received its official number this period. It is growing as it rotates further onto the visible disk. It produced the period’s strongest flare, the M2.6, plus additional C- and B-class events. Its increasing magnetic complexity makes it the primary region of concern going forward.

AR4472 (beta) was the most prolific flare producer of the period. It fired an M1.0 and several C-class events. Its position near the southeast limb makes full analysis difficult. But it shows some mixed-polarity magnetic structure worth monitoring.

The remaining 5 numbered regions were small and simple. They were either stable or in gradual decay. Several areas of pores appeared in the western hemisphere. But most decayed before developing into numbered sunspot groups.

Blasts from the sun?

Two CMEs were observed during the period. But neither is expected to deliver a direct hit to Earth.

Past 24 hours in space weather

Solar wind

On the space weather front, solar wind conditions remained subdued. The influence of a waning coronal hole high-speed stream faded further. Speeds ranged between 350–420 km/s, settling near 400 km/s by the end of the period. Meanwhile, the total interplanetary magnetic field (IMF) ranged from 5–7 nT.

Bz and magnetic coupling

The Bz component was variable throughout. It briefly dipped as far south as ?7 nT. But it recovered quickly. That southward dip was too brief and weak to drive significant geomagnetic activity. As a result, Earth’s magnetic shield stayed mostly closed.

Earth’s magnetic field

Over the past day, Earth’s magnetic field ranged from quiet to unsettled (Kp 1–3). No geomagnetic storm thresholds were reached. Conditions continued transitioning toward background levels.

What’s ahead? Sun–Earth forecast

Flare activity forecast

Forecasters expect low-to-moderate levels to continue through June 23. A chance (35%) exists for M-class (R1) flares. Both AR4472 and AR4473 drive the outlook. And AR4473 is especially worth watching as it grows and rotates further into view.

A slight chance (5%) for an X-class event cannot be entirely ruled out if AR4473 continues to develop. But this remains a low probability for now.

Geomagnetic activity forecast

• June 21: Expect quiet-to-unsettled conditions (Kp 1–3) as the coronal hole stream influence continues to fade. No significant aurora is expected. And today being the June solstice means the shortest nights of the year in the Northern Hemisphere, further limiting any viewing window.
• June 22–23: Expect mostly quiet conditions (Kp 1–2) under background solar wind. But a slight enhancement is possible late on June 22 into June 23 if the flank of the June 19 CME delivers a glancing blow. If realized, an unsettled-to-active spell (Kp 3–5) could develop. At Kp 5, aurora could reach Seattle, Edinburgh, and the Scottish Highlands. But the brief summer nights at these latitudes will severely limit any viewing window.
• June 24: A very low-confidence possibility exists for minor unsettled conditions (Kp 3–4) if the flank of the June 20 CME arrives as one model run suggests. But quiet background conditions are more likely. A new coronal hole fast-wind enhancement may also begin arriving, though confidence remains low.

Sun news June 20: Bam! M flare from a newcomer sunspot

We called it! Yesterday, we flagged a newcomer sunspot region as one to watch. And it delivered. This region sparked a M1.3 flare at 1:51 UTC on June 20. The blast triggered an R1 (minor) radio blackout over the Philippine Sea, southeast of Japan.

And this newcomer now has a name. It has been officially designated AR4472. It sits near the sun’s northeast limb (edge), still too close to the horizon for a complete magnetic analysis. Specialists initially assigned a simple alpha configuration. But we need to wait until more of this region rotates into view to define its magnetic complexity more fully.

Here is what makes this exciting. AR4472 already fired an M-class flare before fully rotating into view. If it carries significant magnetic complexity once fully visible, it could become a major player. As always, the sun keeps us guessing. Stay tuned!

Past 24 hours of sun news

(11 UTC June 19 – 11 UTC June 20)

Flare activity

Over the past day, solar activity reached moderate levels with the production of an M1.3 flare. In total, the sun fired 8 flares: 1 M-class (moderate), 2 C-class (common), and 5 B-class (weak).

• Strongest flare: M1.3 from AR4472 in the southeast at 1:51 UTC on June 20. It triggered an R1 (minor) radio blackout over the Philippine Sea southeast of Japan.
• Lead flare producer: AR4470 in the northeast topped the list. It fired 4 of the 8 flares. And newcomer AR4472 closely followed with 3 flares, including the M1.3. The remaining flare came from elsewhere on the disk.

Sunspot regions

Currently, the Earth-facing solar disk shows just 4 numbered active regions. All four carry either alpha or beta configurations. In other words, they’re magnetically simple. So the risk of strong flares from the currently numbered regions stays low.

But AR4472 is the one to watch. It already delivered an M1.3 flare before fully rotating into view. Its position near the northeast limb means its true complexity remains hidden for now. As more of this region rotates onto the disk, its potential will become clearer.

Blasts from the sun?

Experts are currently modeling and analyzing the M1.3 flare from AR4472. A faint coronal mass ejection (CME) was observed during the event. But initial analysis suggests an Earth miss. The ejecta appears directed too far southward. In addition, a filament eruption in the southeast around 3 UTC on June 19 produced a slow-moving CME. Specialists anticipate a portion of that ejecta to deliver a glancing blow at Earth around June 23.

Past 24 hours in space weather

Solar wind

Solar wind speeds continued at moderate-low levels throughout the period. Meanwhile, the total interplanetary magnetic field (IMF) stayed at weak levels.

Bz and magnetic coupling

The Bz component kept shifting intermittently between northward and southward throughout the period. At the time of this writing on June 20, the Bz shows a northward orientation. As always, a southward Bz is what favors auroral displays.

Earth’s magnetic field

Over the past day, Earth’s magnetic field ranged from quiet to unsettled levels (Kp 1–3). Currently, the Kp index sits at level 2.

Sun news June 19: A fiery prominence from the far side

Departed sunspot region AR4464 is still making its presence felt from the far side of our sun! It continued blasting flares and hurling plasma into space with beautiful jets and prominences, especially the gorgeous jet-like eruption shown above. It was strong enough to show above the southwest horizon, even though AR4464 has been on the far side for more than two days. That is a testament to just how energetic this region remains. Will we see AR4464 return to the Earth-facing disk, after traveling around the sun’s far side? Stay tuned!

Past 24 hours of sun news

(11 UTC June 18 – 11 UTC June 19)

Flare activity

Over the past day, solar activity continued at very low levels. In total, the sun fired 12 flares: 2 C-class (common) and 10 B-class (weak).

• Strongest flare: C2.0 from AR4470 in the northeast at 11:56 UTC on June 18.
• Lead flare producer: An as-yet-unnumbered newcomer in the southeast topped the list. It fired 7 of the 12 flares, more than double its nearest rival.

Sunspot regions

Currently, the Earth-facing solar disk shows just 3 numbered active regions. All three carry stable beta configurations. They are magnetically simple. And the risk of strong flares from the currently numbered regions stays low.

Notably, a newcomer in the southeast is barely showing its nose over the horizon. It has not yet received an official number, but it is already firing flares from the very edge of the southeast limb (edge). One to watch.

Blasts from the sun?

Available coronagraph imagery showed no coronal mass ejections (CMEs) during the period.

Past 24 hours in space weather

Solar wind

Solar wind speeds averaged moderate-low levels throughout the period. Meanwhile, the total interplanetary magnetic field (IMF) started the period at weak levels. Then it gradually increased to moderate levels.

Bz and magnetic coupling

The Bz component pointed southward for the first 16 hours of the period. Then at around 3 UTC this morning, it shifted sharply northward for about 4 hours. At 7:20 UTC it returned southward and remains there at the time of this writing. As always, a southward Bz favors auroral displays.

Earth’s magnetic field

Over the past day, Earth’s magnetic field ranged from quiet to unsettled levels (Kp 1–3). Currently, the Kp index sits just above level 2.

Sun news June 18: Sunspot region keeps flaring from the far side

Yesterday we saw the fiery sunspot region AR4464 departing over the southwest horizon. And over the past day, this prolific region continued to fire a string of jets and prominences from the far side. They were large enough to appear over sun’s limb (edge), and several of the eruptions were registered as C and B flares. This region just can’t say goodbye!

Past 24 hours of sun news

(11 UTC June 17 – 11 UTC June 18)

Flare activity

Over the past day we’ve seen a slight increase in flare production, but the overall activity level remained very low, as the majority of the flares produced were B-class (weak). In total, the sun fired 12 flares: 3 C-class (common) and 9 B-class (weak).

• Strongest flare: C2.5 from active region AR4464 in the southwest at 15:06 UTC on June 17.
• Lead flare producer: A newcomer now numbered AR4470 became the lead flare producer of the period as it blasted out 4 flares of the 12. It was shortly followed by AR4464 with 3 flares from the far side.

Sunspot regions

Currently our star shows just 2 numbered active regions on its side we see from Earth. Both are magnetically simple, with stable beta configurations. We have not seen a spotless day since February 2, 2026. Could one be coming soon? Perhaps, although there is a string of sunspot regions on the far side that may appear on the Earth-viewed solar disk in the coming days.

Blasts from the sun?

A couple of coronal mass ejections (CMEs) were observed on available coronagraph imagery during the period. A first CME detected at 0:38 UTC on June 17 was concluded to have an Earth-bound component. An additional CME was registered by LASCO C2 at 1:35 UTC on June 17. Both events are under modeling and analysis. We will bring you further data as soon as it is released.

Past 24 hours in space weather

Solar wind

Solar wind speeds saw a slight increase to moderate-high levels from 12-to-16 UTC on June 17, before dropping back to moderate-low levels for the rest of the period. Meanwhile, the total interplanetary magnetic field (IMF) drew back to weak levels.

Bz and magnetic coupling

The Bz component was oriented south for most of the day. A few northward peaks were seen, but they were weak. As always, a south oriented Bz component favors auroral displays.

Earth’s magnetic field

Over the past day, Earth’s magnetic field remained at quiet levels (Kp 0–2). No geomagnetic storm conditions occurred. Currently, the Kp index sits just above level 1.

Sun news June 17: Fiery sunspot region departs from view

While solar activity dropped to very low levels over the past day, one sunspot region remained fiery. We’re talking about AR4464, which kept firing jets as it made its way out of view over the southwest solar horizon. And just as it reached the edge of the solar disk, it sparked a gorgeous farewell prominence. Bye, AR4464!

Past 24 hours of sun news

(11 UTC June 16 – 11 UTC June 17)

Flare activity

Over the past day, solar activity dropped to very-low levels, as the majority of the flares produced were B-class (weak) flares. In total, the sun fired 8 flares: 2 C-class (common) and 6 B-class (weak).

• Strongest flare: C1.2 from active region AR4465 in the northwest at 5:20 UTC on June 17.
• Lead flare producer: AR4464 was the top flare producer of the period. It blasted 4 flares out of the 8 of the period. It was shortly followed by AR4465 with 3 flares. Today’s lead flare producer has left the building and gone to the far side.

Sunspot regions

4 numbered active regions can be seen from Earth on the solar disk. AR4465 lost its (gamma) magnetic complexity and today it shows a simpler (beta) configuration.  All the rest of the sunspot regions are magnetically simple and relatively inactive.

Blasts from the sun?

No Earth-directed coronal mass ejections (CMEs) observed on available coronagraph imagery during the period.

Past 24 hours in space weather

Solar wind

Solar wind speeds averaged at moderate levels during the period. Meanwhile, the total interplanetary magnetic field (IMF) started to show an increase at 1 UTC on June 17 that lasted until 6 UTC when it started to draw back to weak levels this morning.

Bz and magnetic coupling

The Bz component was oriented north for most of the day. As a result, Earth’s magnetic shield stayed firmly closed and auroral activity stayed suppressed.

Earth’s magnetic field

Over the past day, Earth’s magnetic field continued at quiet levels (Kp 1–2). No geomagnetic storm conditions occurred. Currently, the Kp index sits just above level 1.

Sun news June 16: Gorgeous eruption! Sun-stuff still awaited

Over the past day, we observed a gorgeous eruption of solar material over the southwest solar horizon. Take a look above. Beautiful! Meanwhile, we are still awaiting a possible glancing blow at Earth from a burst of sun-stuff that left the sun on June 12. This could disturb our magnetic field, though forecasters aren’t expecting any geomagnetic storming. Celestial geometry is not helping aurora watchers right now. We are just a few days from the June 2026 solstice, which arrives on Sunday morning. The angle at which Earth sits relative to the sun does not cooperate much for auroral displays this time of year. This effect is the opposite of what occurs during the equinoxes, when a favorable angle boosts aurora chances.

Past 24 hours of sun news

(11 UTC June 15 – 11 UTC June 16)

Flare activity

Over the past day, solar activity remained in a lull at low levels. In total, the sun fired 9 flares: 6 C-class (common) and 3 B-class (weak).

• Strongest flare: C1.9 from an incoming as-yet-unnumbered active region in the northeast at 18:51 UTC on June 15.
• Lead flare producer: This northeast newcomer topped the list. It fired 6 of the 9 events, including the C1.9 peak.

Sunspot regions

Currently, the Earth-facing solar disk shows 5 numbered active regions. AR4465 (beta-gamma) regained a gamma component during the period. The remaining sunspot regions are magnetically simple and relatively inactive.

Blasts from the sun?

Available coronagraph imagery showed no Earth-directed coronal mass ejections (CMEs) during the period. But forecasters continue to track the CME that departed the sun on June 12. It may deliver a glancing blow around June 16–17. A direct hit is not expected. But it could modestly enhance geomagnetic activity upon arrival. No G1 (minor) geomagnetic storms are expected from this event.

Past 24 hours in space weather

Solar wind

Solar wind speeds averaged moderate-low levels during the period. Meanwhile, the total interplanetary magnetic field stayed weak. But it showed a slight increase at the end of the period. That uptick could be an early sign of the approaching CME material.

Bz and magnetic coupling

The Bz component kept shifting between north and south. But the strongest and longest peaks pointed northward. As a result, Earth’s magnetic shield stayed firmly closed and auroral activity stayed suppressed.

Earth’s magnetic field

Over the past day, Earth’s magnetic field continued at quiet levels (Kp 1–2). No geomagnetic storm conditions occurred. Currently, the Kp index sits just above level 1.

Sun news June 15: Sun-stuff could give us a glancing blow tomorrow

The sun has taken a breather over the past 24 hours, with only minor C-class (common) flares sputtering from a handful of small, magnetically simple sunspot regions. But solar activity from a few days ago could soon bring excitement to Earth. A glancing blow from a coronal mass ejection (CME) that left the sun on June 12 could brush Earth tomorrow, potentially lifting geomagnetic activity to active levels.

Past 24 hours of sun news

(11 UTC June 14 – 11 UTC June 15)

Flare activity

Over the past day, solar activity remained at low levels. In total, the sun fired 7 flares: 5 C-class (common) and 2 B-class (weak). No M-class (moderate) or X-class events occurred.

• Strongest flare: C1.7 from AR4464 at 1:50 UTC on June 15.
• Lead flare producer: AR4464 topped the list with 4 of the 7 events. These included the C1.7.

Sunspot regions

The Earth-facing solar disk shows 4 numbered active regions. All are magnetically simple and relatively inactive.

Blasts from the sun?

Available coronagraph imagery showed no Earth-directed coronal mass ejections during the period. But forecasters continue tracking a CME that departed the sun on June 12. It may deliver a glancing blow around June 16–17. A direct hit is not expected. But it could modestly enhance geomagnetic activity upon arrival.

Past 24 hours in space weather

Solar wind

Solar wind speeds reflected the continued but waning influence of a coronal hole high-speed stream. Speeds gradually declined to normal levels over the period. Meanwhile, the total interplanetary magnetic field remained weak.

Bz and magnetic coupling

The Bz component showed no significant southward dips. It remained weak and variable. As a result, Earth’s magnetic shield stayed firmly closed. And aurora activity stayed suppressed.

Earth’s magnetic field

Over the past day, Earth’s magnetic field stayed quiet (Kp 1–2). No geomagnetic storm conditions occurred.

The sun in recent days

Earlier sun images

Sun images from our community

More sun images from our community

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

Bottom line: Sun news for June 21, 2026: M flare on the June solstice! CME glancing blow possible June 22–23. Happy solstice!

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The post Sun news: M flare brightens the June solstice! first appeared on EarthSky.

The 2026 June solstice falls at 8:25 UTC on June 21. That’s 3:25 a.m. CDT.

Northern Hemisphere summer

The June solstice marks the year’s northernmost sunset and sunrise. It brings the year’s longest period of daylight to the Northern Hemisphere (and shortest period of daylight in the Southern Hemisphere). North of the Arctic Circle, the sun neither rises nor sets but stays above the horizon continuously around the clock.

In the Northern Hemisphere, noontime shadows are shortest at this solstice. It’s the year’s highest sun, as seen from the Tropic of Cancer and all places north.

For us in the Northern Hemisphere, the June solstice signals the beginning of summer. For the Southern Hemisphere, winter starts at this solstice.

The solstice is a whole-Earth event. It happens at the same instant for all of us – the instant the sun reaches its northernmost point in our sky. But our clocks say different times.

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Southern Hemisphere winter

Earth’s orbit around the sun – and tilt on its axis – have brought us to a place in space where our world’s Northern Hemisphere has its time of greatest daylight: its longest day and shortest night. Meanwhile, the June solstice and northernmost sun brings the shortest day and longest night south of the equator.

This solstice marks the beginning of Southern Hemisphere winter.

It marks the lowest sun and longest noontime shadow for those on the southern part of Earth’s globe.

South of the Antarctic Circle, the sun neither rises nor sets but stays beneath the horizon for 24 hours.

Northernmost sunset, but not latest sunset

The sun sets farthest north on the day of the solstice, bringing the longest day for the Northern Hemisphere. But this summer solstice doesn’t bring the latest sunset. And it doesn’t bring the earliest sunrise. The exact dates vary with latitude, but the sequence is always the same: earliest sunrise before the summer solstice, longest day on the summer solstice, latest sunset after the summer solstice.

For the Southern Hemisphere, where it’s winter now, the latest sunrise – and earliest sunrise – don’t come on the day of the solstice either. Again, the exact dates vary with latitude. But the sequence is always the same: earliest sunset before the winter solstice, shortest day on the winter solstice, latest sunrise after the winter solstice.

Each solstice marks a turning of the year

Even as this northern summer begins with the solstice, throughout the world the solstice also represents a “turning” of the year.

In fact, to many cultures, the solstice can mean a limit or a culmination of something. From around the world, the sun is now setting and rising as far north as it ever does. The solstice marks when the sun reaches its northernmost point for the year.

Then after the June solstice, the sun will begin its subtle shift southward on the sky’s dome again. Thus even in summer’s beginning, we find the seeds of summer’s end.

Read more: All you need to know about the June 2026 solstice

Bottom line: The northernmost sunset (and sunrise) happen at the June solstice. Here’s some quick info that’ll help you connect with nature on this special day.

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The post The northernmost sunset is on the June solstice, today! first appeared on EarthSky.

The June solstice arrives at 8:25 UTC (3:25 a.m. CDT) today, June 21, 2026. For the Northern Hemisphere, it’s the longest day and shortest night. For the Southern Hemisphere, it’s the shortest day and longest night. Watch this video with EarthSky’s Deborah Byrd to learn the top 3 sky sights on this June solstice 2026. And what does “sun stands still” really mean? Watch in the player above or on YouTube.

EarthSky’s Will Triggs visited Stonehenge for the sunrise on June 20, 2025. Hear about his experience in the player above, or on YouTube.

Read more: June solstice in 2026: All you need to know

A 1st quarter moon for this year’s solstice

June 22 and 23 evenings: Moon and Spica

Read more: Virgo the Maiden represents a harvest goddess

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.

June 26 and 27 evenings: Moon near Antares

Read more: Massive ruby red Antares is the Scorpion’s Heart

June 28 evening: Moon near Teapot

Read more: Teapot of Sagittarius points to Milky Way center

June 29: Full Strawberry Moon and Lowest (Highest) Full Moon

Why is June’s full moon the lowest full moon of 2026 for viewers in the Northern Hemisphere? And why does the same moon ride high from the Southern Hemisphere? Join EarthSky’s Deborah Byrd as she explores the geometry behind this month’s full moon. Bring your questions and join us live at noon CDT (17 UTC) on Wednesday, June 24. Watch in the player above or on YouTube.

June 30 evening: Moon and Teapot

Read more: Sagittarius the Archer and its famous Teapot

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.

June evening planets

June morning planets: Northern Hemisphere

June stars

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

Boötes the Herdsman

The Big Dipper and Little Dipper

Hercules the Hero and the Hercules Cluster

Have fun exploring the sky!

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

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

Sky dome map for visible planets and night sky

Read more: Guy Ottewell explains sky dome maps

Heliocentric solar system visible planets and more

Read more: Guy Ottewell explains heliocentric charts.

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.

Bottom line: EarthSky’s visible planets and night sky guide. Today is the June solstice! It’s the longest day of the year for the Northern Hemisphere and the shortest for the Southern Hemisphere.

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

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34 dust devils on Mars in 1 shot!

Mars is famous for its tornado-like whirlwinds, made of the dusty debris coating its surface. These are dust devils. They form the same way on Mars as they do on Earth: as the sun warms the ground, the ground then heats the thin layer of air above. Then that air rises quickly through the cooler, dense air above, spiraling around a small area of low pressure.

On June 17, 2026, ESA shared an image from its Mars Express orbiter of 34 dust devils it captured on the red planet’s surface back on December 7, 2024. Can you spot all the dust devils in the image above?

Look closely. This region of Mars is in a valley system known as Mamers Valles. It holds ridges and plateau-like areas along with many small craters. Although the dust devils may look tiny – as a small light-colored dot with a shadow – in reality, dust devils on Mars can grow even larger than those on Earth. Martian dust devils can tower up to 5 miles (8 km) high and span hundreds of yards wide.

The location of the dust devils is in the image at the bottom of this post.

Then check out the original here. The largest version shows a whopping 34 dust devils!

More on Mamers Valles

Mamers Valles lies in Mars’ northern hemisphere. It consists of of valleys and canyons, some of which stretch for more than 600 miles (1,000 km). The higher areas are mesas, cliffs and some debris-covered glaciers. The glaciers lie at the base of the steep slopes. The terrain shows evidence that it was carved by flowing materials, such as water, ice and lava, sometime in its past.

Answer key for the dust devils

Bottom line: The Mars Express orbiter caught this view of the red planet, which is peppered with whirlwinds. Can you spot 34 dust devils in this one shot of Mars?

Via ESA

The post 34 dust devils on Mars in 1 shot! Can you spot them all? first appeared on EarthSky.

In 2026, the Northern Hemisphere’s summer solstice – and Southern Hemisphere’s winter solstice – falls on June 21, 2026, at 8:25 UTC (that is 3:25 a.m. in central North America; translate UTC to your time). Read more about the June solstice.

Science news, night sky events and beautiful photos, all in one place. Click here to subscribe to EarthSky’s free daily newsletter.

Longest sunsets in June and December

Here’s a natural phenomenon you might not have imagined: the longest sunsets happen around the time of the solstices. That is, it takes more seconds for the body of the sun to sink below your western horizon around the solstices, and fewer seconds around the equinoxes. It’s true whether you live in Earth’s Northern or Southern Hemisphere.

As viewed from both the Northern and Southern Hemispheres, the sun rises and sets farthest north at the June solstice and farthest south at the December solstice.

Now consider that the farther the sun sets from due west along the horizon, the shallower the angle of the setting sun. That means a longer duration for sunset at the solstices.

Meanwhile, at an equinox, the sun rises due east and sets due west. That means on the day of an equinox, the setting sun hits the horizon at its steepest possible angle.

Longest sunsets are how long?

The sunset duration varies by latitude. But let’s just consider one latitude: 40 degrees north, which is the latitude of Denver or Philadelphia in the United States, Sardinia in the Mediterranean, or Beijing in China.

At that latitude, on the day of a solstice, the sun sets in about 3 minutes and 15 seconds.

That’s half a minute longer than the sunset at the same latitude on the day of an equinox. The equinox sun at 40 degrees north latitude sets in roughly 2 minutes and 45 seconds.

At more northerly temperate latitudes, the sunset duration is greater; and at latitudes closer to the equator, the sunset duration is less. Near the Arctic Circle (65 degrees north latitude), the duration of a solstice sunset lasts about 15 minutes. At the equator (0 degrees latitude), the solstice sun takes a little over 2 minutes and 15 seconds to set.

Regardless of latitude, however, the duration of sunset is always longest at or near the solstices.

The sunsets are longer in December than June

As it turns out, the sunset and sunrise are a tad longer on the December solstice than they are on the June solstice.

That’s because the sun is closer to Earth in December than it is in June. Therefore, the sun’s disk looms a bit larger in our sky in December, and so it takes slightly longer to set.

Additionally, the closer December sun moves eastward upon the ecliptic at a faster clip, helping to slow down the December solstice sunset (and sunrise) even more. For instance, at 50 degrees north latitude, the winter solstice sunset (sunrise) lasts about 4 minutes and 18 seconds, or about 8 seconds longer than the sunset (sunrise) on the summer solstice.

And now you know!

Some sunsets from EarthSky Community Photos

Bottom line: Here’s a natural phenomenon you might never have imagined: the longest sunsets happen around the time of a solstice.

Help support EarthSky! Visit the EarthSky store for to see the great selection of educational tools and team gear we have to offer.

The post For all of Earth, longest sunsets around the solstice first appeared on EarthSky.

The North Star, aka Polaris

The North Star, also known as Polaris, appears to stay fixed in our northern sky. It marks the location of the sky’s north pole – the north celestial pole – which is the point around which the whole starry northern sky turns as the Earth rotates. That’s why you can always use Polaris to find the direction north.

But even though the North Star doesn’t appear to move, a timelapse video reveals that it actually does. It makes its own little circle around the sky’s north pole every day. That’s because the North Star is offset a little – about 0.65 degrees – from celestial north. So Polaris makes a circle that’s 1.3 degrees in diameter each day.

Why do stars move, anyway?

Why does Polaris – and all the other stars in the sky – move at all? The answer is Earth’s spin. Because Earth rotates counter-clockwise when looking from above the North Pole, the sun in the daytime – and most stars at night – appear to rise in the east and set in the west.

Depending on your latitude, certain stars will be close enough to your nearest pole that they never rise or set. Never dipping below the horizon, they instead circle above you constantly. These are called circumpolar stars.

And the North Star is a special example of a circumpolar star. Because it lies almost exactly above Earth’s northern axis, it’s like the hub of a wheel. It doesn’t rise or set, and barely moves in a circle. Instead, it appears – to the eye – to stay put in the northern sky.

How high in your sky?

The North Star not only points toward the north, but its height in the northern sky also matches your latitude on earth. If you are sailing the Caribbean at 16° north latitude, the North Star will be about 16° high in your sky. If you are sailing around Nova Scotia, at 44° north latitude, then the North Star will be about 44° high in your northern sky. Each degree north or south equals 69 miles (111 km), so traveling 690 miles north or south will change your latitude, and the North Star’s elevation, by 10 degrees.

Read more: Polaris is the North Star

Taking turns as the North Star

A motion of Earth called precession causes our axis to trace out an imaginary circle on the celestial sphere every 26,000 years. And that means the star closest to the north celestial pole isn’t fixed.

Thousands of years ago, when the pyramids were rising from the sands of ancient Egypt, the North Star was an inconspicuous star called Thuban in the constellation Draco the Dragon.

Twelve thousand years from now, the blue-white star Vega in the constellation Lyra the Harp will be a much brighter North Star than our current Polaris.

Polaris could be a name for any North Star. Our current Polaris used to be called Phoenice. It is the 49th brightest star in the sky. It is not known for its brightness, but for its unique position in the sky.

Proper motion

By the way, Polaris – like all stars – has more than one kind of motion. There’s the movement we see on our sky, caused by the Earth’s rotation. And then there’s each star’s actual motion through space.

The stars we see in our night sky are all members of our Milky Way galaxy. All of these stars are moving through space, but they’re so far away we can’t easily see them move. That’s why the stars appear fixed relative to each other. And it’s why, for the most part, we see the same constellations as our ancestors.

But over time, this movement – called proper motion – rearranges the patterns of stars we see in our sky. For Polaris, that movement is small, about 46 arcseconds in 1,000 years. That is about 1/40th of the diameter of the full moon as seen from Earth. So when you’re talking about stars moving or staying fixed, remember … they are all moving through the vastness of space. It’s just the relatively short time of a human lifespan that prevents us from seeing this grand motion.

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Bottom line: The North Star is a symbol for constancy. But a video or star trails image reveals that it makes its own little circle around the sky’s north pole every day.

Polaris is the present-day North Star of Earth

Use the Big Dipper to find Polaris, the North Star

The post Does the North Star ever move in the sky? first appeared on EarthSky.

The Royal Astronomical Society originally published this article on June 11, 2026. Edits by EarthSky.

No crisis? Universe’s expansion is accelerating after all, study says

Our universe’s expansion is still accelerating despite recent claims suggesting otherwise, an international team of astrophysicists say.

They have refuted a study published last year claiming the growth of the universe is slowing. Instead, the researchers insist there is no flaw in the widely-accepted theory that a mysterious force known as dark energy is driving the expanding cosmos.

The researchers include two Nobel laureates and represent institutions worldwide. They say the debate that followed last November’s revelations was the result of a scientific misunderstanding, rather than a cosmic grenade threatening to blow apart everything we know about the universe.

They published their rebuttal on June 10, 2026, in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society.

Rebutting an extraordinary paper

The new research is a direct rebuttal of a study by a team of South Korean researchers published in November 2025. Their paper made the claim that the universe’s expansion might in fact be slowing down. This would be due to the influence of dark energy – which acts as a kind of anti-gravity – weakening over time.

Lead author Phil Wiseman, from the University of Southampton, said:

The previous and well accepted measurements were, in fact, fine and our current understanding of the fate of the universe remains robust.

Thankfully we have averted this crisis. But the mystery about why the rate of expansion of the universe is still accelerating remains.

By proving our measurements are correct, we can get back to trying to understand what this dark energy actually is, rather than wondering if it exists at all.

What were the flaws?

The international team of researchers involved in the new study included Adam Riess and Brian Schmidt, who collectively won the 2011 Nobel Prize in Physics alongside Saul Perlmutter.

The trio studied Type Ia supernovae, violent, luminous white dwarf star explosions and determined that more distant objects appeared to move faster. This lead to their conclusion that the universe’s expansion was accelerating.

This has been the globally-accepted theory ever since, although last year’s research by the South Korean team threatened to upset the applecart. It claimed that, as the universe aged, these supernovae had different maximum brightnesses. This tricked astronomers into thinking the cosmos was accelerating when it was in fact slowing.

But the University of Southampton-led researchers found an error in how the age of these stars was estimated. They say the previous findings incorrectly assumed the age of a galaxy was the same as the age of the star that exploded.

The experts also said the South Korean paper failed to account for the mass of host galaxies. That is a standard correction used in modern cosmology to prove accuracy.

Riess added:

Extraordinary claims require especially careful testing.

What we find is that when we calibrate these supernovae, accounting for different host environments and populations, the evidence for cosmic acceleration remains remarkably consistent.

Science is never settled

Mark Sullivan, also from the University of Southampton, said challenging accepted theories and observations was fundamental to science.

This is how progress is made. Although this idea did not turn out to be correct, it has opened up new ways of thinking about how supernovae explode and how we can measure dark energy more accurately.

Fellow co-author Brodie Popovic agreed:

We’ve recently been really focused on astrophysics of the explosions and how they impact cosmology.

This was a good opportunity to go back and go over all of our assumptions; it turns out, yes, we do understand this stuff and we’re accounting for it in our cosmology measurement.

Bottom line: Rebutting a surprising paper from 2025, a new study has found that the universe’s expansion is accelerating after all.

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The post No crisis? Universe’s expansion is accelerating, study says first appeared on EarthSky.

• Scientists have discovered many rocky exoplanets around other stars. But which ones are the most likely to be habitable?
• A new model of habitable exoplanets is narrowing down the search. It focuses on the size and atmosphere of these planets.
• The model predicts which planets could have life-supporting atmospheres.

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New habitable exoplanets model

Rocky planets – like Earth – are common in our galaxy. That’s good news in the search for life as we know it. But how can we tell which of these exoplanets are the most likely to be habitable? To answer this question, a team of scientists has developed a new model called Smaller Than Earth Habitability Model (STEHM).

The team, led by Stanford University in California, said on June 4, 2026, that the model aims to find which planets are the most likely to support life by focusing on their size and atmospheric characteristics. The study centers on planets ranging from about half the size of Earth up to Earth-sized.

The only way to determine if a planet could have life, scientists think, is to analyze its atmosphere. Advances in technology are increasingly allowing astronomers to do just that. They look for biosignatures, gases or other chemicals in the atmosphere that could be byproducts of life.

The new peer-reviewed paper was published in The Planetary Science Journal on June 4, 2026.

The Smaller Than Earth Habitability Model

Michelle Hill of the Stanford Doerr School of Sustainability led the new study about habitable exoplanets. She said:

The only way that we’re going to ever find out if there are signatures of life out there is by observing the atmosphere of these planets.

Maybe there’s life on other planets under the ground, but we are never going to be able to see it because we can’t send something to those exoplanets. The best chance we’ve got is looking for signs of life by analyzing atmospheres from afar.

With this in mind, she developed the Smaller Than Earth Habitability Model (STEHM). This model looks at factors that can affect a rocky planet’s ability to create and maintain an atmosphere, within the context of its size.

Size and mass are important. If a planet is too small or low mass, it could lose its atmosphere. This is especially true for low-mass stars like red dwarfs. Intense flare and radiation activity can strip a planet of its atmosphere if it’s too close.

And rocky planets need atmospheres to help protect their surfaces from the harsh conditions of space.

The researchers created six different planetary models. They ranged from half the size of Earth to Earth-sized. The planetary profiles included density and thickness of the mantle and the planet’s overall density. All six modeled planets had carbon dioxide atmospheres. The planets were modeled as what scientists call stagnant lid planets. That is, unlike Earth and its ever-shifting crust, these model planets had rigid, unmoving surfaces.

How long do exoplanets sustain their atmospheres?

STEHM found that planets with a radius at least 80% of Earth’s can maintain their atmospheres for 10 billion years or more. But that’s only if they are comfortably far away from their star, like Earth is.

If a planet is smaller than that, it could lose its atmosphere within 1 billion years. One caveat though; if a planet’s radius is about 0.7 that of Earth, it could maintain its atmosphere, depending on other factors.

Carbon helps maintain atmospheres

How much carbon a planet has when it first forms is also important. Carbon helps to contain and preserve heat. That heat can be essential to keeping a planet habitable. Heat-producing elements such as thorium, uranium and potassium in the mantle also help maintain heat inside the planet.

But if those elements become depleted, the mantle, in turn, will begin to cool off. As a result, volcanic activity ceases. And that means no more carbon dioxide production, leading to loss of the atmosphere.

But if a planet has a thicker mantle, and smaller core, it could hold on to more carbon and elements for a longer time.

Too much heat is bad

As already noted, heat inside a planet is essential for life. But what if there’s too much heat? The model found that if a planet has too much heat too early, that can reduce the lifespan of the atmosphere.

These planets – dubbed ‘hot-start’ planets – are very hot on the inside after formation. In fact, their mantles can melt. This exposes the atmosphere to stellar radiation. This is not good, but the habitable zone also plays a role. That is the region where temperatures could allow a rocky planet to have water on its surface. The planet needs to be far enough from its star to not burn up from stellar radiation. But it also can’t be too far from its star, where temperatures are too frigid.

Inspiration from Mars

Mars was actually the original inspiration for STEHM. The researchers wanted to know if Mars could have ever held onto a thicker atmosphere. The model showed that the odds were always against it, due to the planet’s small size and lack of plate tectonics.

The model also correctly predicted the fate of Venus, with its thick carbon dioxide atmosphere.

Next, the researchers want to create profiles of mobile lid planets, like Earth, that do have tectonic activity. Those ones will then be compared to the stagnant lid planets.

Bottom line: Researchers have developed a new habitable exoplanets model to find out which rocky exoplanets could possibly support life.

Source: Smaller Than Earth Habitability Model (STEHM): The Lower Size Limit for Atmosphere Retention in the Habitable Zone

Via Stanford University

Read more: Habitable exoplanets could exist around nearby stars

Read more: How much water on exoplanets does life need?

The post New habitable exoplanets model narrows down search for life first appeared on EarthSky.