What The Curiosity Rover Has Learned In Its First 10 Years On Mars

One of the biggest open questions that scientists have about Mars is whether there was ever life there. They are pretty sure nothing lives there now, but there could have been microbial life present millions of years ago when there was liquid water present on the planet’s surface (via NASA). Finding out whether something lived so long ago isn’t easy, but research using data from Curiosity has taken us some steps closer to an answer. The rover has detected organic molecules containing carbon and hydrogen in Mars’ Gale Crater, and while these molecules don’t definitely indicate life was there, they do provide the basic building blocks for life. The big takeaway from this finding is that Mars could indeed once have been habitable.

Another important finding from Curiosity and SAM is the strange case of the variable methane in Mars’ atmosphere. Scientists know that Mars has methane gas in its atmosphere, but Curiosity has found that the amount of methane present seems to vary widely, from high measurements of 21 parts per billion units by volume (ppbv) to lows of fewer than 1ppbv. Scientists still don’t fully understand why the rate is so variable, as it could be coming from various sources like being released from rocks or seeping up through the surface from underground. Then the gas is disappearing somehow, perhaps related to Mars’ day and night cycle.

There’s plenty of other work Curiosity has done in addition to these two big topics. The rover has found evidence about the history of water on Mars, including identifying an ancient oasis, as well as learning about the geological history of the planet and investigating the presence of another element that is important for life, nitrogen.