MRO finds new evidence for dry ice formation of gullies on Mars

Before and after images showing the formation of a new gully channel in Terra Sirenum, taken between Nov. 5, 2010 and May 25, 2013. Credit: NASA/JPL-Caltech/Univ. of Arizona

Before and after images showing the formation of a new gully channel in Terra Sirenum, taken between Nov. 5, 2010 and May 25, 2013. Credit: NASA/JPL-Caltech/Univ. of Arizona

Some of the most interesting features on the surface of Mars are its gullies, often found on crater walls or other slopes, first seen from orbit back in 2000. They resemble gullies on Earth created by water, but the origin of located on Mars have become the subject of much debate. These gullies appear to be actively forming today, and are not just some relic of past activity that took place millions of years ago. But on Mars, water can’t exist for long on the surface even if it is briny, so how are these gullies being created? New observations from the Mars Reconnaissance Orbiter (MRO) spacecraft suggest that dry ice (frozen carbon dioxide) may actually be responsible. The new findings have been published in the journal Icarus.

Continue Reading →

Image Gallery: reddish bands on Europa’s surface

converted PNM file

The icy surface of Europa, with reddish bands of water ice mixed with hydrated salts. Credit: NASA/JPL-Caltech/SETI Institute

The icy surface of Europa, with reddish bands of water ice mixed with hydrated salts. Click for larger version. Credit: NASA/JPL-Caltech/SETI Institute

A “new” (previously unreleased) colour view of Europa’s surface from the old Galileo spacecraft; the image is a product of clear-filter grayscale data from one orbit, combined with lower-resolution colour data taken on a different orbit. The surface here is primarily almost pure water ice, with reddish bands of water ice containing hydrated salts. The image area measures approximately 163 km by 167 km (101 by 103 miles). What might be found in the subsurface ocean below? More information here.

Continue Reading →

Titan’s hidden ocean might be as salty as the Dead Sea

Illustration of what Titan’s interior is thought to look like, with a rigid ice shell above the salty water ocean below. Credit: NASA/JPL-Caltech

Illustration of what Titan’s interior is thought to look like, with a rigid ice shell above the salty water ocean below. Credit: NASA/JPL-Caltech

Saturn’s moon Titan is known for its methane seas, lakes, and rivers; surprisingly Earth-like in appearance yet distinctly alien at the same time. But there is also evidence for another ocean, this one of water, below the surface. Little is known about this hidden watery world, but now new results suggest it is likely very salty – as much as the Dead Sea on Earth.

Continue Reading →

New study shows how salts could make liquid water on Mars

The Phoenix lander was the first mission to land near the Martian north pole. Was it also the first to see evidence of liquid water on Mars? Credit: NASA/ JPL-Caltech/University of Arizona/Texas A&M University

The Phoenix lander was the first mission to land near the Martian north pole. Was it also the first to see evidence of liquid water on Mars? Credit: NASA/ JPL-Caltech/University of Arizona/Texas A&M University

The search for evidence of water on Mars, past or present, has been one of the driving forces behind the exploration of the Red Planet for several decades now. While orbiters, landers, and rovers have all found abundant evidence for a lot of water in Mars’ ancient history, the question of whether there could still be any of the wet stuff existing today is still open and unanswered. There are hints, but proof is still elusive. Now, a new study provides new information on how liquid water could be found on Mars’ surface today, albeit in small amounts or for brief periods of time.

Continue Reading →

Cassini at Saturn: 10 years of amazing planetary science and more to come

Mosaic image showing Saturn backlit by the Sun, one of the most beautiful and surreal photographs sent back by Cassini. Credit: NASA/JPL-Caltech/Space Science Institute

Mosaic image showing Saturn backlit by the Sun, one of the most beautiful and surreal photographs sent back by Cassini. Credit: NASA/JPL-Caltech/Space Science Institute

The Cassini mission to Saturn has been one of the most successful and exciting in all of space exploration history. That amazing spacecraft is now celebrating its 10th anniversary today orbiting the ringed planet, after having revolutionized our understanding of the Saturnian system, which is like another entire smaller-scale solar system. But there is still much more to come!

Continue Reading →

Gliese 832c: astronomers discover another nearby potentially habitable exoplanet

Artist’s conception of Gliese 832c. Credit: PHL @ UPR Arecibo/NASA Hubble/Stellarium

Artist’s conception of Gliese 832c. Credit: PHL @ UPR Arecibo/NASA Hubble/Stellarium

As the number of exoplanets discovered continues to grow exponentially, the number of potentially habitable worlds out there continues to increase as well. Astronomers have now reported finding another one of the nearest known of these kinds of planets so far, Gliese 832c.

Continue Reading →

What is this ‘Magic Island’ that appeared on Titan?

Before and after images showing the appearance of "Magic Island" in Ligeia Mare on Titan. Credit: NASA/JPL-Caltech/ASI/Cornell

Before and after images showing the appearance of “Magic Island” in Ligeia Mare on Titan. Credit: NASA/JPL-Caltech/ASI/Cornell

Titan is a complex world, reminiscent of our own planet in many ways, with mountains, seas, lakes, rivers and rain. Albeit the liquid on this super-cold moon is methane/ethane instead of water, but the visual similarities are striking. Just how geologically active Titan might be in other ways however isn’t really known yet, but a new discovery might provide some clues. What looks like a new small “island“ has appeared in one of the hydrocarbon seas, where it wasn’t before. Is it really an island, or something else?

Continue Reading →

Blog update: new RSS feed

There is a new RSS feed for the blog - http://feedpress.me/themeridianijournal – trying out FeedPress as an alternative to the regular, default feed. Please update if you were using the old one, thanks!

Continue Reading →

Kapteyn b: a very old and potentially habitable exoplanet

Artist's conception of Kapteyn b. Credit:PHL @ UPR Arecibo/Aladin Sky Atlas

Artist’s conception of Kapteyn b. Credit: PHL @ UPR Arecibo/Aladin Sky Atlas

Astronomers have discovered the oldest known (so far) exoplanet which might be capable of supporting life; the planet, Kapteyn b, is likely more than twice the age of the Earth. The planet was found by an international team of astronomers, led by Guillem Anglada-Escude from Queen Mary University.

Continue Reading →

Advanced ‘SPHERE’ exoplanet imager sees first light

Infrared image taken by SPHERE of a circumstellar dust ring around the star HR 4796A. The light from the star itself in the centre of the image has been blocked out. Credit: ESO

Infrared image taken by SPHERE of a circumstellar dust ring around the star HR 4796A. The light from the star itself in the centre of the image has been blocked out. Credit: ESO

Taking actual photographs of distant planets orbiting other stars is no easy task, and even in the best ones obtained so far, the planets still only look like tiny points of light. A new advancement in this area though promises to improve our view of these worlds.

Continue Reading →

Follow

Get every new post delivered to your Inbox

Join other followers: