The Martians have landed in Pasadena.
No, not little green men.
Six hundred Red Planet experts descended on Caltech this week for the Eighth International Conference on Mars.
It's a chance for researchers from around the world to discuss the big burning questions they have about our celestial neighbor.
Caltech planetary sciences professor Bethany Ehlmann helped organize the event, and she spoke with KPCC. Her answers have been edited slightly for length.
So, this is the eighth Mars conference. But it's not an annual event. The first was way back in 1973 and others seem to happen at random intervals thereafter. Why this year?
"This year is an exciting year to collect our perspectives after the Phoenix lander in 2007, after the successful landing of Curiosity and its nearly one year of Mars exploration on the surface and the continuing data that we're getting back from the orbiters. It's time to figure out what have we learned, what questions are still out there."
What are the big questions?
"The big questions relate to environments, relate to the possibility of life. The biggest level questions I think remain the same, but what we know about it, I think, has changed in the last decade or so, in terms of — we know that Mars was once a watery world. The argument now has switched to: Was that water deep in the sub-surface? Was it at the surface? How icy versus how warm and wet?"
Is there enough data available to answer these questions?
"Well, we've made progress. Science is iterative, right? So every few years we collect, reassess, see what kind of progress we've made. We really have the benefit, though, over the last decade, of having been part of a program of Mars exploration, where rovers built upon orbiters, which in turn feeds to where to send the next rover. So we've collected a wealth of information. And we're starting to approach for a few landing sites the level of knowledge that we'd have if we sent out a geologist on Earth."
If you could run a mission yourself, where would you send the rover?
"Oh, there's so many places to go on Mars. I think that's also been one of the lessons of the decade. Mars, like Earth, is a planet. And you get a little bit different perspective depending on whether you land in Antarctica versus landing in the Amazon versus landing here in Southern California, as to what the history of the planet is, what its environments have been like. So I think we need to visit multiple spots on Mars to figure out what's going on."
What should we be paying attention to in the next year when it comes to Mars exploration?
"In the fall, you're going to see the orbital insertion of MAVEN [Mars Atmosphere and Volatile EvolutioN]. That's a mission run by the University of Colorado, [UC] Berkeley, with NASA, that's looking to study the upper atmosphere. So what does that mean? Why do we care? Well, one of the reasons we care is [that] a question on Mars is: Where is the water? The thought is that some of it could have escaped. So MAVEN's going to look at what the rates of escape are today to get a sense of how much water is Mars losing. What does that tell us about what Mars was once like in the past? So stay tuned for MAVEN.
"Stay tuned also for India's mission. They're sending an orbiter mission. That, too, is supposed to do orbit insertion in the fall.
"And two other things coming up that get us to the surface — in 2015, we will have the launch of the Insight Mission. It's geophysics. It's going to bring a seismometer to Mars and measure heat flow of Mars. So we'll see if there are Marsquakes. And then, finally, instrument selections are coming up for the 2020 rover. 2020 is a long way off, but the planning starts now in terms of picking the instruments and designing them for the next round of rovers on Mars."
This story has been updated.