The subject of water on Mars is one of the most highly debated in planetary science; various missions have provided ample evidence that the planet used to be a lot wetter than it is now, with rivers, lakes and maybe even oceans. Most scientists now generally agree on this, but as to how much water there was, how long it lasted and how warm the environment was, is another question. There have been apparent conflicting lines of evidence, and now findings from the Curiosity rover have only added to the mystery. Curiosity has revealed a paradox of sorts – it has found abundant evidence for ancient lakes in now-dry Gale crater, but at the same time has not found evidence for a previous thicker atmosphere with more carbon dioxide, which normally would be needed for water to remain liquid on the surface. These two lines of evidence seem to contradict each other, so how to resolve this puzzle?
The Curiosity rover has now resumed its journey toward Mount Sharp after experiencing some delays due to a faulty drill mechanism. The rover conducted a short drive over the past weekend toward a new location with “plenty of science targets to choose from.” Being on the road again is of course a relief to mission engineers and scientists, although the problems with the drill are still being diagnosed. As has come to be expected, Curiosity again made some exciting science observations in 2016, which continue to show that this region on Mars was once a lot more habitable in the ancient past, and perhaps bringing us closer to answering the question of whether life ever actually did exist there.
NASA held another press briefing this week about the latest findings from the Curiosity rover on Mars, detailing new evidence that this former lake environment was once quite hospitable for possible life. The findings were announced from the fall meeting of the American Geophysical Union in San Francisco. In a related development, there is also new evidence from Curiosity that organics have not only been definitively found by the rover, but that they may be more widespread on Mars than previously thought.
Ever since first landing in August 2012, the Curiosity rover has helped to revolutionize our understanding of Mars and has seen some incredible scenery along the way. It has travelled across an ancient lakebed and gazed at towering sand dunes and buttes, and now it is ready to begin the next phase in its mission: gradually ascending the lower slopes of Mount Sharp, the massive mountain sitting in the middle of Gale crater. The layers in the mountain will provide more clues as to how the Martian environment changed from being much wetter than it is now, to the dry but cold desert we see today. This next chapter in the rover’s mission is part of a two-year extension which began Oct. 1, 2016.
Mars has often been compared to deserts on Earth, and for good reason: it is pretty much a barren landscape with a lot of sand and rocks everywhere. Sometimes, the similarities can be quite striking, and the terrain in Gale crater where the Curiosity rover is roaming around is a good example. The rover is currently in a region of stunning scenery – buttes and mesas which are very reminiscent of ones on Earth. This area could easily be mistaken for the American southwest if it weren’t for the dusty, pinkish sky and complete lack of vegetation. Curiosity is now getting a close-up look at these formations, which are not only beautiful but record a long and fascinating geological history.
The Curiosity rover is continuing to travel through the ancient and eroded buttes and mesas which are part of the Murray Buttes formation. Very reminiscent of the terrain in the desert regions of the American southwest. Included are a couple new panoramas, processed by Thomas Appéré. All images are available on the mission website.
The Curiosity rover has been sending back some beautiful images of the Murray Buttes which it has now reached, near the base of Mount Sharp, on Mars. There are many buttes and mesas in this region, including in the foothills of the mountain itself. The current header graphic for the blog is also part of a new panoramic image of the buttes, processed by James Sorenson. All images are available on the mission website.
NASA’s current rovers, Curiosity and Opportunity, are continuing to explore their respective regions of Mars, with new findings that are providing yet more clues as to the geological history and potential past habitability of this fascinating world. They have also both just completed significant steps in their journeys and are now entering new and exciting phases of their missions. Both missions have found yet more evidence that the Mars we see today – cold and dry – was once much wetter and potentially habitable, at least for microorganisms.
Mars’ atmosphere is thin and cold, composed primarily of carbon dioxide along with other trace gases and some water vapour. Evidence has continued to mount, however, that the rarified atmosphere we see today once used to be much thicker and possibly warmer, making it potentially more life-friendly early on. Just how thick and how warm is still a subject of much debate, but there is also another interesting aspect to all of this: New evidence from the Curiosity rover has shown that the Martian atmosphere also used to have a lot more oxygen in it than it does now. Today, only very small traces of oxygen can be found, as opposed to Earth’s oxygen-rich atmosphere. So what does this mean? Could there be biological implications?
This image from the Curiosity rover on sol 1294 shows some very delicate rock formations on Naukluft Plateau, shaped by blowing Martian sand. The thin atmosphere and lower gravity also help in the formation of such spindly protrusions. Similar ones have also been seen before by the rover.