Scientists aren’t messing around with this Man on Mars thing. They’ve been shooting spacecraft at the Red Planet since the mid-1960s. These days, the place is a veritable space parking lot.
With the recent revelation of the discovery of fluid water (we already knew there was ice on Mars), the pull of the planet becomes even stronger. And the questions — Is there life on Mars? Has there ever been? Can we live there? — become even more pressing.
How are scientists going to answer them? A stroll through that parking lot of information-gathering spacecraft may tell:
Mars Reconnaissance Orbiter
OK, so this isn’t actually parked. Orbiter, launched in August 2005, is the satellite that has done the real work of mapping the planet.
On the scene since November 2006 (Mars, remember, is 140 million miles away; it takes some time to get there), Orbiter has returned more data than all the other probes to the planet combined, according to NASA. Its mission is to examine the surface, the subsurface and the atmosphere with high-resolution cameras and a spectrometer. In effect, the data that Orbiter gathers informs the folks back home exactly where to send the probes and — someday — men and women.
Mars Science Laboratory rover Curiosity
Launched in November 2011, this car-sized vehicle is NASA's boots-on-the-ground. It’s part of the Mars Science Laboratory, which landed in Gale Crater in August 2012. Its mission: To evaluate whether that area of the planet could once have supported life.
Curiosity can analyze samples of atmosphere and surface, and has already found things in the surface like oxygen, nitrogen, carbon and hydrogen, “all essential chemical foundations for life.” With its on-board spectrometer, Curiosity captured evidence that dark streaks found on certain ridges are signs of a flow of salty water.
Artist's conception of an exploration rover on Mars. (Photo: NASA/JPL/Cornell University)
Mars Exploration rover Opportunity
This rover has been tooling around on the surface of the Red Planet for more than a decade. Launched in July 2003, it landed in a crater in January 2004, checked out some bedrock and immediately settled the debate on whether Mars ever had water.
Opportunity, which takes breathtaking images, has put in more miles than any other land vehicle ever (off-Earth vehicle, that is). Its original mission was to last three months, but it’s still going, preparing for its eighth Mars winter. It had a twin, the rover Spirit, that worked until March of 2010 before it got stuck and lost power.
Mars Atmosphere and Volatile EvolutioN satellite (MAVEN)
The youngest member of the Mars team, MAVEN just celebrated its one-year anniversary on the scene. Launched in November 2013, it arrived in September 2014.
MAVEN is measuring the Martian atmosphere — it’s the first spacecraft to directly do so — and how quickly it’s being lost to space. If scientists can figure out how fast gasses are escaping the atmosphere, the theory goes, they may be able to get an understanding of what the atmosphere once looked like and whether it could have, at one time, sustained life.
Launched in April 2001, this orbiter arrived in March 2002 and is still mapping and providing imaging through cameras and a spectrometer. It’s the longest-working Mars orbiter ever. One of its key jobs now is to act as a communications relay for the craft on the surface.
These dark, narrow streaks called recurring slope lineae, which flow downhill on Mars, may have been formed by flowing water. The blue color seen upslope of the dark streaks is not believed to be related to their formation, but instead caused by the presence of the mineral pyroxene. (Photo: NASA/JPL/University of Arizona)
Express is a European Space Agency orbiter; the Italian Space Agency and NASA are bumming rides to run some experiments. Launched in June 2003, it started relaying images in 2004. It includes a radar that can penetrate the surface — looking for sub-surface water — and a tool for studying solar winds.
On to the future ... and beyond
NASA has plans to launch a couple more craft next year, one a lander that aims to better “understand the processes of planet formation and evolution in the inner solar system.” The other launch, in conjunction with the European Space Agency and the Russian agency, Roscosmos, will be of an orbiter, designed to survey “trace gases in the planet’s atmosphere that may indicate active geological or biological processes.” The second mission also will test a new entry, descent and landing module. If all goes well, both should be up and running by late 2016 or early 2017.
And in 2020, a new mission is expected to be launched which hopes to sample Mars' surface and bring the samples back to Earth.
"It's very likely, I think," Alfred McEwen, a scientist at the University of Arizona who is in charge of the high-resolution camera on Orbiter, said during Monday’s announcement, "that there's life somewhere in the crust of Mars."
When he talks about life, McEwen is talking about microbes, not little green men. One thing is certain, though: These scientists will keep sending stuff to Mars until they find out for sure what's there.