It’s a good thing I’ve come down with a cold and have little to do but sit at my computer. Because in the last week, some very interesting news stories have been piling up that just scream for recognition. And wouldn’t you know it, more than a few have to do with our big red neighbor Mars, that world many human beings will one day think of as home.
The first story comes to us from the Siding Spring Observatory in New South Wales, where noted astronomer Robert McNaught recently sighted an new comet. From his observations, the icy interloper appeared to have originated in the Oort Cloud – a hypothetical cloud surrounding the solar system and containing billions of icy planetesimals that were cast out from our Solar System billions of years ago.
After news of the discovery was released, the astronomers at the Catalina Sky Survey in Arizona looked back over their observations to find “prerecovery” images of the comet dating back to Dec. 8, 2012. These observations placed the orbital trajectory of the comet – now known as C/2013 A1 – through the orbit of Mars on Oct. 19, 2014. This means, in essence, that this comet could very well strike the Red Planet late next year.
Luckily, NASA’s Jet Propulsion Laboratory has run the calculations and indicated that their close approach data suggests the comet is most likely to make a close pass of the Martian surface. And by close, they mean at roughly 0.0007 AU, or approximately 100,000 kilometers (63,000 miles) from the Martian surface. So in all likelihood, Curiosity and Opportunity will be safe from a serious impact that could turn them into scrap metal!
But of course, predicting its exact trajectory at this time is subject to guess work, and ongoing observations will be needed. No doubt, the predictions will be refined a the next 20 months go by, and we’ll know for sure if this comet plans to miss Mars completely, or slam head-on into the surface at 200,000 km/h (126,000 mph).
The second bit of news comes to us from the good-ole Curiosity Rover! Roughly four weeks after conducting the first drilling operation into the Martian surface, the Rover ate its first sample of the grey dust that resulted. The delivery of the two aspiring-sized tablets of dust took place on Feb. 22nd and 23rd respectively after the robotic arm delivered them into the rover’s Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM) laboratories for analysis. Results expected in two weeks!
Among other things, the results from the analysis are expected to give clues as to what the color change between the red surface and the grey interior means. One theory is that it might be related to different oxidations states of iron that could potentially inform us about the habitability of Mars inside the rover’s Gale Crater landing site.
At the same time, the Mars Science Laboratory team expects to find further evidence of what life was like in previous geological eras. The Curiosity team believes that the area inside the Gale Crater, known as Yellowknife Bay, experienced repeated exposure to flowing liquid water long ago when Mars was warmer and wetter – and therefore was potentially more hospitable to the possible evolution of life.
The rover will likely remain in the John Klein area for a month or more to obtain a more complete scientific characterization of the area which has seen repeated episodes of flowing water. Eventually, the six-wheeled mega rover will set off on a year long trek to her main destination: the sedimentary layers at the lower reaches of the 5 km (3 mile) high mountain named Mount Sharp.
And last, but not least by any stretch of the imagination, is the discovery of “hieroglyphs” on the Martian surface. While they might appear like ancient glyphs to the untrained eye, they are in fact evidence of past subsurface water. The images were caught by the HiRISE camera on the Mars Reconnaissance Orbiter as it passed the surface area known as Amazonis Planitia.
Known as ‘rootless cones,’ these geological features are the result of an explosive interaction of lava with ground ice or water contained within the regolith beneath the flow. Vaporization of the water or ice when the hot lava comes in contact causes an explosive expansion of the water vapor, causing the lava to shoot upward, creating what appears to be a button hole on the surface.
In the past, Mars scientists have used geological patterns on Earth to make sense of similar ones found on Mars. For example, when the Curiosity Rover discovered veins of hydrated calcium in the rock surface in the Gale Crater, they compared them to similar patterns found in Egypt to determine that they were the result of long-term exposure to water flows. In this case, the rootless cones found in Amazonis Planitia are comparable to those found in Iceland’s Laki Lava Flow (as seen above).
According to Colin Dunas, from the US Geological Survey, the cones are rather large and most likely very old:
“The cones are on the order of a hundred meters across and ten meters high. The age of these specific cones isn’t known. They are on a mid- to late-Amazonian geologic unit, which means that they are young by Martian standards but could be as much as a few hundred million to over a billion years old.”
Only time will tell if any subsurface water is still there, and hence usable by future teams of terraformers and settlers. According to Dundas, the odds are not so good of that being the case. Given the surface depth at which the ice was found, not to mention that at the low latitude at which it was found (22 degrees north), shallow ground ice is unstable. Dundas added that since ice stability varies as the obliquity changes, it’s even possible that ice has come and gone repeatedly since the lava erupted.
Too bad. That could have come in really handy for hydroponics, fuel cells, and even restoring surface water to the planet. Guess future generations of Martians will just have to look for their ground and irrigation water elsewhere, huh? Just another challenge of converting the Red Planet to a green one, I guess 😉
Stay tuned for more news Mars. As it stands, there’s plenty to be had! Stick around!