Category Archives: mars climate

Curiosity, Mars, mars climate, Mars Express

Frosty Mars

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A Cool Place to Be

Mars is a lot like Earth in some ways. Sure it’s a barren desert planet now, whereas Earth is not. But, like Earth, it has seasonal changes, and if you look at some of its landforms, they look disturbingly familiar. Take this image that the Mars Curiosity rover sent back.

 

This panorama is a mosaic of images taken by the Mast Camera (Mastcam) on the NASA Mars rover Curiosity while the rover was working at a site called “Rocknest” in October and November 2012. Courtesy NASA/JPL-Caltech. Click to enlarge.

Looks a lot like some places here on Earth, doesn’t it? You can see mountains off in the distance (actually part of the crater that the spacecraft landed in), and lots of sand dunes and rock outcrops nearby. When I see a picture like this, I want to go on a geology field trip — which is what Curiosity is doing for us!

The folks at the European Space Agency have a mission called Mars Express, and it’s doing a bang-up job of sending back high resolution images of Mars from orbit.

A High-Resolution Stereo Camera (HRSC) nadir and colour channel data taken during revolution 10778 on 18 June 2012 by ESA’s Mars Express have been combined to form a natural-colour view of Charitum Montes. The heavily cratered region in this image is at the edge of the almost 1,000-km-long mountain range, which itself wraps around the boundary of the Argyre impact basin, the second largest on Mars. Courtesy ESA.

The whiter-looking regions here are covered with something most of us are familiar with if we live in climates where winter brings snow and cold weather: frost. In this case, it’s carbon dioxide frost, which forms when the atmosphere gets cold enough to freeze it into particles of ice that coat the ground.

Wondering how cold it is on Mars?  It has a very thin atmosphere, so even though Mars does get sunlight, the temps on the ground are pretty darned cold, usually well below zero (-55 C or -67 F for an average). At its coldest, Mars temps can plunge down to -110 C (-170 F).  I’ve seen suggestions that Mars temperatures can rise above zero on warm summer days; how far they rise depends on the local heating and how much sunlight the ground is getting.

There are more cool images of this cratered region at the link above. They show just how rugged the terrain of Mars is, and remind us that some worlds can look (and sometimes feel) just like home, even if they’re more than 100 million kilometers apart right now!

 

 

 

 

Mars, mars climate, Mars Express

Mars and the Search for Water

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Mars Express Radars Mars

New results from the MARSIS radar on Mars Express give strong evidence for a former ocean of Mars (marked in blue on this artist's concept of what early Mars may have looked like when this ocean existed). The radar detected sediments reminiscent of an ocean floor inside previously identified, ancient shorelines on the red planet. The ocean would have covered the northern plains billions of years ago. Credits: ESA, C. Carreau

It’s one of those no-brainer ideas: that water once existed on the surface of Mars.  All you have to do is LOOK at the planet and you see evidence of something that flowed across the surface.  There are washed out valleys, what look like river canyons, and regions that look like the shores of ancient oceans. If we had geologists (areologists?) on the planet, they’d make short work of determining what it was that flowed across the planet’s surface by taking surface samples and analyzing them.

Well, we don’t have people on Mars — yet. But, we do have spacecraft orbiting the planet and sitting on its surface sending us back all manner of daily data about this rusty, red desert world. The European Space Agency’s Mars Express mission has a radar instrument called MARSIS that bounced signals from the surface back to its detectors. The data in those signals told planetary scientists that at least one part of Mars is covered with sediments that were probably laid down on the floor of an ancient ocean.  The sediments contain minerals and possibly some ices that identify the area as the site of an ocean that existed perhaps 3 or 4 billion years ago, when Mars was very young, and possibly warmer and wetter than what we see today.

The oceans probably didn’t last very long; their water frozen into place, or vaporized and escaped through the planet’s thin atmosphere to space. So, the chances for life to form in those oceans were likely pretty thin.  Life or no life, the evidence for water flowing on the Martian surface in the dim recesses of history is pretty exciting. Now, the questions remain: where did all the water go and was there ever a chance that Mars harbored life?  Stay tuned!

Speaking of staying tuned, have you checked in on this month’s “Our Night Sky” at Astrocast.TV?  If not, why not?  Learn what’s up in the February skies!  You might find Mars…