NASA Announces End Of Mars Phoenix Mission
ROBERT SIEGEL, host:
You're listening to All Things Considered from NPR News.
It's getting dark and cold near the north pole of Mars. And while that may not affect your plans directly, the same cannot be said of the Mars Phoenix Mission. Today scientists at NASA said goodbye to their Phoenix Lander, which has run out of power. Last May, the Phoenix Lander landed in the northern polar region of Mars, and since then it's been snapping pictures, making weather measurements, and doing chemical analysis on Martian soil and ice. NPR's Joe Palca has been following that mission. He joins me now. And first of all, Joe, what was the main goal of Phoenix?
JOE PALCA: Well, the main idea was to go to this region near the north polar cap and see if measurements that were taken from space were accurate. And those measurements that were taken from an orbiting satellite that's in orbit around Mars said, wow, it looks like there's a lot of ice underneath the soil. Now, they didn't see it from space because it wasn't bright like ice, but they thought if we get there, maybe we can find some.
SIEGEL: Besides finding ice, did it find other things of interest in the region?
PALCA: Well, first of all, the thing is that it did find ice.
PALCA: I mean, the best - the strangest thing is it lands, and it looks out to the horizon and all you see is red dirt, and then it goes and it points the camera underneath the landing deck, and it's like a little ice skating rink that's been cleared away by the retro rockets as it came down. They say, ooh, that's a good sign. And then they have this arm that digs down and it finds a little ice in the soil. But it also found some interesting salts that they weren't expecting, perchlorate salts, which are possibly a nutrient for bacteria, maybe not good for your drinking water, might be OK for it. Also found that the soil was less acidic than they expected. And the other cool thing was a few weeks ago, they saw snow falling from the Martian clouds.
SIEGEL: Did the Phoenix Lander die a natural death?
PALCA: Yeah, I think you'd have to say nobody was terribly surprised. As you said, the sun was going down. This is a solar-powered spacecraft. They were seeing - getting less and less power each day as the sun was dropping below the horizon. And things kind of sped up when there was a dust storm on Mars, and that causes even less sunlight to reach the ground. And I think they are estimating that the mission ended about three weeks earlier than they expected.
SIEGEL: Any chance it will rise from its ashes when the sun comes out again in the spring?
PALCA: Well, it's already done that once because that's where it got its name. It was the mission that had been shelved and then, it was...
SIEGEL: Bureaucratically, it rose from its ashes.
PALCA: But in this case, probably not. Because as the winter progresses, it gets colder and colder. Carbon dioxide freezes out of the atmosphere. And they say that the Lander will be encased in a block of dry ice, which is not a great way to spend the winter. I should say, by the way, Robert, that there are still two functioning Mars probes on Mars. These two rovers...
SIEGEL: Rovers, yes.
PALCA: That you and I have been talking about for five - more than five years now. They are closer to the equator. And so even though they're getting less sun now, they're getting enough to keep moving.
SIEGEL: But their job was not to burrow in and take samples the way the Lander was.
PALCA: No. No, they were supposed to look around and point its camera and scrape rock and things like that.
SIEGEL: Lessons for future missions if any of our listeners are going to Mars.
PALCA: Well, they may not be, but there are some probes that are about to go to Mars. And I think probably one of the most important missions is how to deal with Martian soil. Now I am going to throw a technical term at you here, Robert. And I hope you get this: clumpy.
SIEGEL: It's clumpy soil.
PALCA: It's clumpy soil. And they drop the soil on top of this little grate that was supposed to have it go into the machine, and it was too clumpy to get through.
SIEGEL: I see.
PALCA: So they now have an anti-clumping technology development program for Mars to make sure they can get soil into their instruments.
SIEGEL: OK, Joe. Thank you.
PALCA: You're welcome.
SIEGEL: That's NPR's Joe Palca on the end of the Mars Phoenix's mission.