Mars is a busy place these days, with multiple rovers and orbiters exploring the planet. Out of the several spacecraft currently in orbit, NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) is a fairly recent addition, having been at Mars for just over two years now. Usually, things are pretty routine, but this week the spacecraft had to make an unplanned evasive maneuver – to avoid a collision with one of Mars’ two small moons, Phobos!
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?
Thirteen years. That is how long NASA’s Opportunity rover has now been exploring Meridiani Planum on Mars; not bad for a robot which was designed with a hoped-for nominal 90-day mission. Today marks the 13th anniversary of the landing of Opportunity, on Jan. 24, 2004 PST (Jan. 25, 2004 UTC). The mission since then has been nothing short of incredible, as Opportunity soon found evidence that Meridiani Planum used to be a much wetter place than it is now. It was a place where microbial life could have existed; whether it actually did or not is still unknown but Opportunity continues to provide more clues as it continues exploring vast sandy plains and mountainous crater rims.
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.
Water on Mars is one of the most talked about and controversial subjects in planetary science. It is now well-known that Mars used to be a much wetter place than it is now, although just how much water there was, and how long it lasted, is still a matter of considerable debate. Direct evidence from rovers, landers, and orbiters, including observations of ancient riverbeds, gullies, and lakes, has shown how at one time Mars was much more Earth-like than it is today. Rovers like Curiosity, Opportunity, and Spirit have actually driven over long-dried-up lakebeds, salty playa lakes, and regions of ancient geothermal activity such as hot steam vents. Now, the Opportunity rover is going to visit another feature not yet explored by any other rover or lander: a gully thought to have been carved by water millions or billions of years ago.
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.
NASA’s InSight mission to Mars will now go ahead as planned, it was announced today. After a delay due to a vacuum leak last December, with a launch originally slated for last March, it was unclear whether the mission would still be given the green light for a later launch. But now NASA has approved a launch for spring 2018.
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.