Category Archives: Mars Express

Mars, Mars Express, water

Mars Express and the Story of Water on Mars

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Looking for Evidence of Mars Water

Mars 3d image
A 3D image of Aurorae Chaos and Ganges Chasma from Mars Express. Courtesy ESA.

I haven’t written about Mars lately, and since I’m still gathering material for my annual “gift” column, let’s look at the Red Planet. I got a press release from the Mars Express mission (run by the European Space Agency), talking about a region that connects the great Valles Marineris to nearby lowlands. If you ever get a chance to go to Mars (and that could be a distinct possibility for some in the next generation of explorers, Valles Marineris should be a “must see” stopping point. It’s a huge collection of canyons carved out by various geological processes on the Red Planet. Flooding certainly seems to have played a role there, so scientists have focused on the landforms in the regions in and around the Valles Marineris to see how they might have been created. I would imagine that future explorers will head there as soon as they can to get a better and more in-depth understanding of this fascinating region.

A Vision of Formerly Wet Chaos

Mars Express sent back an image of a region called Aurora Chaos, looks as if it has been wet (not to mention inundated) in the past. It what is called “chaotic terrain”, which is jumbled and blocky and was probably formed as the surface collapsed when subsurface ice melted and the water flowed away. Aurora, at its deepest point, is 4.8 kilometers (about 3 miles) lower than the surrounding surface area. That’s much deeper than the Grand Canyon here on Earth.

Aurora Chaos connects to a smoother, flatter area called Ganges Chasma, which also looks like it has been shaped by flowing water. It ends at a plateau region that has carved rocky regions that were likely formed by water or ice deposits that were at different levels during various parts of Mars’s geologic past. The whole area has faults cutting across it, which mean that some sort of activity cracked and broke the “rock basement” that formed these regions. Faults in rock can form when the surface drops, from earthquake activity, or from underground pressure related to volcanism (to name a few reasons).

Whatever activities shaped this region, they occurred early on in Martian history perhaps only in its first couple of billion years.

When the first Martians from Earth make their homes and do their science on the Red Planet, they’ll be able to dig into the surface and do “first person” surveys. What they find will supply rich details for the story of early Mars that spacecraft probes such as the Mars Express mission are telling us from orbit.

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!