It has been an extraordinary year in Mars exploration, with new results and new spacecraft changing our view of the red planet.
It's a much more dynamic planet than we imagined maybe 20 years ago.Professor of Experimental Physics, University of Bern
The highlight for many was the touchdown of NASA's InSight probe, the first ever mission to study the interior of another planet.
The landing sequence - famously difficult, and nicknamed the 'seven minutes of terror' - went perfectly, and there was a huge cheering crowd for the cameras at JPL in California.
InSight may wear an American flag, but it carries European instruments, including a Franco-British seismometer which is being carefully set up on the planet's surface, and a German heat probe which will hammer itself several metres beneath the surface.
One of scientists eager to use InSight data, Lu Pan from the University of Lyon, in France, told Euronews: "It's the first time that we actually specifically aim to study the interior. Because with others, like Pathfinder and MSL we were there to study the environment of Mars, to see if there is water, if there is ice, to see how the climate changed through the four billion years. But this mission is different, we're going to actually put a seismometer on the surface of Mars."
Mars does have a reputation for surprising scientists, and in 2018 it did so when a global dust storm covered the planet.
Fine powder on the surface was stirred up, and the view from the Curiosity rover darkened in a matter of days from a light yellow-ish sky to a menacing orange.
For the scientists it was a once-in-a-lifetime chance, according to ExoMars TGO scientist Ann Carine Vandaele, from the Royal Belgian Institute of Space Aeronomy:
"We had the time to take some measurements before the storm, so some reference measures, and then we were able to see the entire evolution of it from a regional storm to a global storm, and now obviously to see the storm dissipate."
Another surprise came when Italian researchers used ESA's MarsExpress spacecraft to identify what appears to be a 20-kilometer wide liquid water lake under the Martian south pole.
Probes have found signs that there is water beneath the Martian surface in the form of ice in many places, including towards the equator.
"This is important," says Håkan Svedhem, ExoMars TGO Project Scientist at ESA. "Liquid water has always been seen as a pre-requisite for life. It doesn't necessarily mean that we have it there, but it is one ingredient that we would need to have life."
The search for life on Mars is happening in earnest. The joint European and Russian ExoMars rover is being built by Airbus in the UK now and will fly there in 2020. It is the first rover to ever head to the red planet with the direct intention of searching for life now, or in the past.
With six spacecraft and two active probes already at Mars, we're learning a lot, says Nicolas Thomas, Professor of Experimental Physics at the University of Bern in Switzerland.
"Our view of Mars has changed in the past 20 years. It's a much more dynamic planet than we imagined maybe 20 years ago. And that's due to the fact that we now have very high resolution observations where you can see that there are changes occurring."
Perhaps humans will be able to witness those changes a decade from now, as private space firm Space X yet again reiterated in 2018 that it intends to send people to the red planet before 2030."