Category Archives: water

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.

astronomy, gravitational lenses, masers, quasars, water

Water, Water Everywhere… and When

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Even 11.1 Billion Years Ago

Water appears to be ubiquitous throughout the universe. Which is to say that astronomers spot traces of water vapor in various parts of the universe like other planets, moons, and throughout our galaxy. But, often enough, astronomers find H2O vapor in water masers. These are beamed radiation sources that are similar to lasers, but radiate at microwave wavelengths. These masers are often found in regions where hot, dense dust and gas are coalescing — like galaxy cores and starbirth regions.

So, astronomers have wondered how early in the universe water vapor might have existed. Another way to ask that question is to wonder how far away the most distant water vapor could be “seen” by our telescopes?  Water masers showing vapor have been found in galaxies close to ours, of course. But, what about more distant onces?

The quad gravitational lens MG J0414 + 0534, courtesy of VLBI.
The quad gravitational lens MG J0414 + 0534, courtesy of the extended Very Large Baseline Interferometer radio array (eVLBI).

The most recent answer came from data taken with the Effelsberg 100-meter radio telescope in Germany (operated by the Max Planck Institut for Radio Astronomy). Graduate student Violette Impellizzeri used the telescope to study the quasar MG J0414 +0534, which lies about 11.1 billion light-years away from us. We see it here in radio wavelengths that have been gravitationally lensed by an intervening galaxy (that is, the wavelengths of radiation and light from the more distant quasar are being bent by the gravitational influence of a massive galaxy that lies between us and the quasar).

The signature of water vapor was spotted in the radio data taken by Impellizzeri. It probably exists in clouds of dust and gas that feed a supermassive black hole at the center of the quasar. The detection of the water was later confirmed by observations made with the Expanded Very Large Array.

Make no mistake about it, this is a discovery of water in the very early universe — at a time when the universe was a fifth of its current age. It means that water may have been much more abundant in those early times. Because water masers are active close to galaxy cores, these masers may tell us something about the evolution of black holes and galaxy cores back at a time in the universe’s early history when galaxies were first forming.  I don’t know about you, but I find it fascinating just how something we take so much for granted (and is so commonplace) as water can help us get a look at the earliest epochs of cosmic history.

If you’re interested in reading more about this research, there’s a paper coming out in the December 18, 2009 issue of Nature magazine. Here’s the citation:

A gravitationally lensed water maser in the early Universe, C.M. Violette Impellizzeri, John P. McKean, Paola Castangia, Alan L. Roy, Christian Henkel, Andreas Brunthaler, & Olaf Wucknitz, 2008, Nature (18 December issue)