"The cradle of life does not necessarily require a sun."

The Hydrogen-rich exomoon atmospheres could hold liquid water for billions of years.

A moon lost in interstellar darkness may still be able to hold on to liquid water, no star required. A modeling study suggests that some exomoons orbiting rogue planets could stay warm for billions of years, even after their host worlds are thrown out of their star systems and into the cold of deep space.

The finding challenges the familiar idea that potentially habitable worlds must receive light from a nearby star. Instead, the study points to a different engine for habitability — heat generated inside a moon by tidal stress, then trapped by a thick hydrogen atmosphere.

Rogue planets drift through space without orbiting a star. Astronomers think many of them were thrown out of their original planetary systems during violent gravitational encounters.

When a giant planet gets ejected, the orbits of its moons can become stretched into more elongated shapes. As the moon moves closer to and farther from its host planet, the planet’s gravity repeatedly squeezes and flexes the moon’s interior.

That process, called tidal heating, can generate a steady supply of internal heat. Jupiter’s moon Io offers a familiar example: tidal forces make it the most volcanically active body in the solar system. Europa and Enceladus also show how internal heat can keep water-rich worlds active far from the sun.

Earlier studies had already suggested that rogue-planet moons might stay warm enough for liquid water if they built up thick carbon dioxide atmospheres.

But those models ran into a serious problem. In the deep cold expected around free-floating planets, carbon dioxide can condense out of the air. Once that happens, the atmosphere can collapse, and much of the moon’s heat escapes into space.

The new study tackles that problem by swapping carbon dioxide for hydrogen. Hydrogen is the lightest element, and in Earth’s thin atmosphere it does very little to trap heat.

Under very high pressure, though, hydrogen behaves differently. When hydrogen molecules crowd together and collide, they briefly form pairs and clusters that can absorb infrared radiation.

Scientists call this process collision-induced absorption. In plain terms, a dense hydrogen atmosphere can act like a surprisingly strong heat blanket.

Moonlight reflected off the Amazon river. At the proper angles in our orbit, we aboard ISS can see brief silvery flashes atop water surfaces, illuminating even the darkest places on Earth. I took this photo with Nikon Z9 camera on Expedition 72, during a nighttime pass over South America. More photos like this from space can be seen on my twitter and Instagram, astro_pettit, for those interested

Hey all, I've been looking at some photos that NASA has been releasing (like ones from Discover) and noticing a lot of the cameras on probes/sats they use a triple overlay to creature fully colored (to us) images.

Why is using three separate pictures so common? Is it because it's easier/takes less time to get one wavelength of light at a time?

See the videos here. I apologies for using Imgur, sincerely.

This rocket is a Falcon-9 carrying the Cargo Dragon spacecraft C211 (its fourth flight). It's carrying more than 6,300 pounds of science equipment and supplies to the International Space Station, and should arrive there Thursday after a roughly 52-hour flight.

In a study published July 16 in the journal Science, a team led by Collin Cherubim, a NASA researcher with a doctorate in planetary science from Harvard University, reported the first atmosphere ever found around a rocky planet in a star's habitable zone.

"We tend to think for a planet to be habitable, it has to be mostly rocky, has to have an atmosphere to shield the surface from harmful radiation, but also to keep water present," Cherubim said in a podcast interview with Science.

"And now we know LHS 1140 b meets those criteria."

LHS 1140 b is one of two planets found around LHS 1140, a star about 50 light-years away. (Astronomers label planets with letters, starting at "b," in the order they're found.)

The star is about one-fifth the size of the sun and less than 1% as bright, so its habitable zone sits close in. LHS 1140 b circles it roughly every 25 days.

Most exoplanets, including LHS 1140 b, are found by watching a star dim slightly as a planet passes in front of it. Those passes, called transits, also let astronomers study a planet's air.

During a transit, some of the star's light passes through the planet's atmosphere. By splitting that light into its component parts with a tool known as a spectrograph, scientists can see which colors went missing and work out which gases absorbed them.

Using a powerful spectrograph on a telescope in Chile's Atacama Desert, Cherubim's team found helium around LHS 1140 b, indicating the planet has an atmosphere.

After a long time at the top of my list I finally visited beautiful Oman! I am working on a project where I travel to and document the darkest skies in the world. I set an alarm for 3 AM at our desert camp and hiked out to this spot in pitch darkness. It took me a while to find a photogenic dune like this but I'm THRILLED with the textures on this one. exacctttly the shot I wanted!

With my color correction I went for an "Aladdin" vibe and I think it really hits the spot artistically. I hope you enjoy!

I pointed my phone up randomly while shooting the wrong part of the milky way apparently on my camera and the results. Any tips with editing to bring out the white and purple of the cluster more?