Science: Space

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Friday, 26 July 2013

Helmet Scare Shuts Down Space Walk

Astronaut Luca Parmitano's helmet malfunctioned during Tuesday's space walk outside the International Space Station. Water built up inside, causing the excursion to be abandoned. Audie Cornish talks with NPR's Geoff Brumfiel about what happened yesterday, how serious it was, and what NASA believes could be the cause of the leak.

AUDIE CORNISH, HOST:

We want to warn claustrophobics about our next story and alert aspiring screenwriters because in space, no one expects to drown. Yesterday, more than 200 miles above earth at the International Space Station, Luca Parmitano was about 90 minutes into a spacewalk when he noticed that his head was wet and getting wetter. Water then got into the Italian astronaut's eyes.

His spacewalking buddy, Chris Cassidy, took a quick look and saw nearly a pint of water floating around in Parmitano's helmet. The pair returned to the space station and removed his helmet as quickly as possible. Parmitano is fine. Joining me now is NPR's Geoff Brumfiel. He's been following the story. And Geoff, to start, what is NASA saying happened here, about the possible cause of this water leak?

GEOFF BRUMFIEL, BYLINE: Well, not very much. They had a press conference yesterday and talked about possible sources, but believe it or not, there are actually multiple sources of water in a space suit, so they're not sure where it came from.

CORNISH: I don't understand this. Why would there be water in a space suit in the first place?

BRUMFIEL: Well, the first reason is for the astronauts themselves. Spacewalking is kind of hard work. You're out there for several hours. You're doing physical labor, so they actually have drink bags inside the suits. The other reason is that even though you might think space is really cold, and it is, there's a need to regulate the temperature because you basically have no way to radiate your heat so they actually have these built in radiators that circulate water through the suit that help keep the astronauts cool.

CORNISH: So we're joking around here, but how serious was this yesterday for Parmitano?

BRUMFIEL: It was pretty serious. You know, they stayed calm, as everyone at NASA always does, but they did get him into the airlock quickly. Not as quickly as they would have done in a full-blown emergency, but they got the helmet off right away. They got the gloves off and they had to get him clear. I mean, the problem here is that water in space does not behave like water on earth.

Surface tension causes it to sort of glom together like mercury does, you know. Little beads of mercury will tend to clump up. And so what potentially could have happened is he would have this big floating blob of water in his helmet that he couldn't clear away 'cause it's in his helmet and he could've inhaled it. He could've choked or drowned. So it was potentially, actually, a pretty dangerous situation.

CORNISH: So what happens now? Will Parmitano get a chance to get out of there, to at least get a different suit?

BRUMFIEL: Well, the situation at the moment is that they have to figure out where this water actually came from. The leading candidate at the press conference yesterday was the cooling system, but they really don't know. And they also don't know whether it was an isolated incident or whether it's a problem with all of the space suits.

So in order to get the astronauts back out there, they're going to have to troubleshoot this and they spent all day doing that, the astronauts and mission control. They do have a backup space suit, so if it turns out to be a problem with this one spacesuit, they will probably go back out there at some stage.

And Parmitano's up there till November, so he may have a shot at it.

CORNISH: That's NPR's Geoff Brumfiel. Geoff, thank you so much.

BRUMFIEL: Thank you.

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NASA Uses Photo Of Earth From Saturn To Boost Space Interest

On July 19, a spacecraft nearly 900 million miles from Earth took a color picture of our planet. NASA's Cassini spacecraft snapped the picture from orbit around Saturn. Now scientists have finished processing the picture. It shows a small blue dot next to the giant ringer planet.

MELISSA BLOCK, HOST:

This week, NASA is trying to do its part to raise science literacy. To give people a better understanding of Earth's position in the solar system, the agency's posted a picture of our planet taken from a billion miles away, give or take 100 million miles or so. And joining me now to talk about the picture and why NASA took it is NPR's Joe Palca. Joe, good to see you.

JOE PALCA, BYLINE: Good to see you.

BLOCK: I'm looking at this picture. It's up on NPR.org and we see a spectacular image of Saturn's rings, right, and then a tiny, tiny white dot.

PALCA: Right. So the picture was taken for real. I mean, they took the picture because Cassini, the spacecraft that took the picture, is in this interesting situation where Saturn is between it and the sun. So Saturn is backlit and that makes the rings light up in some interesting ways. But they realize they had a picture of Earth in the frame and so they made a big deal about that.

BLOCK: They're making a big deal about it, why?

PALCA: Well, I think because it's not that scientifically interesting, but it's so cool. And the woman who is in charge of the Cassini mission really got into this and made a big deal about it. Her name is Carolyn Porco and she actually had a video made for the occasion or helped to have a video made for the occasion.

(SOUNDBITE OF VIDEO)

MORGAN FREEMAN: On July 19, you, me, Planet Earth and absolutely everything and everybody on it will have our picture taken from a billion miles away.

BLOCK: Joe, that's Morgan Freeman. That man is everywhere, absolutely everywhere.

PALCA: He is. And Carolyn Porco wrote me that she was thrilled that he was able to do this in short order, which he seems to have done. And I have to say, he's wrong about one thing because people on the other side of the planet who weren't facing Saturn at that moment, people on the other side of the planet weren't in the picture.

BLOCK: They weren't in the picture.

PALCA: But the point of this whole exercise, I think, was to think of this as a teachable moment. I mean, NASA wants to draw attention to the fact that we have been able to get a billion miles in space and orbit Saturn and take pictures back of the Earth. And it does give you perspective on the whole solar system from way out there, a perspective you can't get from, you know, even orbiting satellites, 'cause even there, you only see a part of the earth.

BLOCK: So Joe, when you look at this image, how does it compare with other images of Earth taken from outer space that we've been seeing?

PALCA: Well, most of the images that we see from outer space are more than just a dot in the picture. I mean, there are these famous pictures that the Apollo astronauts took when they were at the moon. You can see a lot of Earth rising over the moon and then, there have been pictures taken from Mars and even last week, there were pictures taken from the Messenger, NASA's Messenger spacecraft that's been in orbit around Mercury.

But there was a really famous picture taken in 1990 from 4 billion miles away by the Voyager spacecraft, so that's further out than this picture was. And if you think this picture of Earth is unspectacular 'cause it's a single...

BLOCK: Well, it's pretty spectacular.

PALCA: Well, the dot is pretty unspectacular. It's just a little dot. But there was an even littler dot in this Voyager picture, but it inspired people because it became known as a pale blue dot and it inspired Carl Sagan, the astronomer, to wax poetic about what it said about our place in the universe.

(SOUNDBITE OF ARCHIVED VIDEO)

CARL SAGAN: Every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every super star, every supreme leader, every saint and sinner in the history of our species lived there on the mote of dust suspended in a sunbeam.

BLOCK: So Joe, reminder, we are motes of dust on a mote of dust. Good to keep in mind when we're all atwitter about the royal baby and things like that.

PALCA: Right. Perspective.

BLOCK: NPR's Joe Palca. Joe, thanks so much.

PALCA: You bet.

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Wednesday, 17 July 2013

Mysterious Radio Bursts, Sent From Deep Space

Reporting in Science, researchers write of discovering four radio bursts from outer space. Physicist Duncan Lorimer, who detected the first such explosion in 2007, discusses what could be causing these radio signals, such as evaporating black holes, an idea proposed by Stephen Hawking in the 1970s.

IRA FLATOW, HOST:

Up next, another edition of the ever-popular We Have No Idea What's Going On Here. Six years ago, my next guest announced a strange discovery. He detected a signal from outer space, a burst of radio emissions, just milliseconds long, from outside our galaxy. It was the first of its kind. No one could figure out what might have caused it, either.

And now we know it wasn't a fluke. Last week, astronomers added four more of these mysterious radio bursts to the list. They tracked them from coming in from all over the universe. The furthest one was 11 billion light-years away. Their findings appear in the journal Science.

But what's causing them? Is it a signal from intelligent life? Should we call back Jill Tarter and the SETI Institute? Or is there more a plausible, but eye-opening explanation like a black hole evaporating? Mm. Duncan Lorimer is the Woodburn professor of physics at West Virginia University in Morgantown, West Virginia. Welcome to SCIENCE FRIDAY.

DUNCAN LORIMER: Good afternoon.

FLATOW: These are very mysterious bursts, and you have no idea what they are.

LORIMER: That's about the top and bottom of it, yes. Yeah, we really - just beginning to come to terms with what they are and what they could be.

FLATOW: Mm-hmm. You discovered the first one of these. They're called the Lorimer bursts, named after you. Did you know that it was going to be so tough to figure it out?

LORIMER: Yes. I think right from the beginning, we were really scratching our heads. The first person to see this was actually my undergraduate student David Narkevic, who was working for me at the time. And when he - I can still remember when he brought it into my office and showed me this plot. We were looking at the data for something else, and we came across this signal. And, yeah, we...

(LAUGHTER)

FLATOW: Did...

LORIMER: We've been losing sleep about it ever since.

FLATOW: Did you think it was a fluke or something?

LORIMER: We were - right from the get-go, we were convinced that it was astrophysically real, because of the properties that we saw in the data. It sweeps across the band, just like we would expect, and like we see in other astrophysical sources. But, yes, because it was only one source, you know, normally scientists and astronomers like lots of sources. A sample of one is always rather uncomfortable.

FLATOW: Yeah. I'm reminded of the discovery of the cosmic background radiation over at Bell Labs back, what was it, in the '50s, and they couldn't figure out what the heck - they thought the instruments were bad.

LORIMER: Right. They thought, at one point, pigeons have - had been getting into the detectors.

(LAUGHTER)

FLATOW: OK. So you've had time to think about it. Can you speculate, then, what these bursts may be?

LORIMER: Yes. It's always fun to speculate. I think we're in an era right now where they're probably going to be more theories than bursts for quite a while. So, you know, you mentioned in your introduction the possibility of extraterrestrial intelligence sending this signal. I think that becomes unlikely now that there's more than one of them. With one source, you could always think about it as some sort of single civilization. But now, you're seeing them, essentially, at different parts of the sky. It's very unlikely that different civilizations would be sending things in exactly the same way.

So I think it's something natural in origin, and that - it's really the time scale is the biggest clue to the size of the object, because it's only a few milliseconds in size. The emitting region can only be a few light-milliseconds across. And so that points to some sort of compact, star like a black hole or a neutron star where, potentially, there's large amounts of energy can be released.

One very interesting paper that came out last week was that it's - it could be electromagnetic energy from a collapsing neutron star, collapsing to a black hole, and energy was released as the star collapsed.

FLATOW: All right. Stay with us, Dr. Lorimer. We're going to take a break. When we come back, we'll talk a lot - lots more about this strange burst coming from outer space. Stay with us. We'll be right back after this break.

(SOUNDBITE OF MUSIC)

FLATOW: This is SCIENCE FRIDAY. I'm Ira Flatow, talking with Duncan Lorimer about the Lorimer bursts, named after him, discovered eight years ago. New bursts discovered of some mysterious energy coming from somewhere in the galaxies. And there's no doubt that you will discover what it is someday, is there?

LORIMER: I think it's fair to say that we'll get to the bottom of it. The story of these bursts closely parallels what happened with gamma-ray bursts about 40 years ago, where people discovered these things and, initially, were very puzzled. But, eventually, it took collaborations - large groups of astronomers to find counterparts of the signal, other parts of the electromagnetic spectrum. And that's what's - one of the things that people are trying to do here. They can locate a galaxy where - that's hosting one of these sources, and you can pin down a distance, and you start to really understand the energetics and really go forward from there.

FLATOW: But in the meantime, you have this giant source of energy sending a beam toward you. Can you use that beam going through space to study what's going on in that space?

LORIMER: Yes. That's one of the very exciting side benefits of these sources. The signals propagate through intergalactic space. You know, we're fairly convinced that they are - they're coming from well beyond the Milky Way, and there's a lot of interest in probing the space between galaxies. We're quite aware of studies of dark matter based on galaxy dynamics and other measurements, so matter that you can't see, that's gravitationally attractive.

Here, we're able to potentially look at the - what's known as baryonic matter, normal matter - in this case, the free electrons that are propagating the intergalactic space. So if we can measure one of these host galaxies, we can literally count the number of free electrons along the line of sight to one of these bursts. And that gives us a brand-new probe of the electron content of the universe, which is really exciting.

FLATOW: Mm-hmm. Do you think these are very rare events, or might they be happening all the time, and you just discovered them?

LORIMER: Well, the radio telescopes that found them have very small fields of view, and the bursts themselves don't last very long. And it's becoming clear from these recent results that the bursts could be going off in - over the entire sky about once every 10 seconds.

FLATOW: Wow. Wow.

LORIMER: So that's quite high when you compare it to supernovae, extragalactic supernovae, gamma-ray bursts. So it's quite a puzzle as to what's producing these events so often.

FLATOW: Might you have to come up with a whole different object there that's making these, that you've never seen before or thought about?

LORIMER: Possibly. This scenario that I outlined before the break about these collapsing neutron stars, the people that came up with that are dubbing those blitzars.

FLATOW: Blitzars?

(LAUGHTER)

LORIMER: Just like an explosion. They get it from the German for thunder and lightening. So, yeah, that's using a nice, fancy word, but it's using a phenomenon that we think we understand, and that is these neutron stars. So, you know, things like that are possible. But, yes, I mean, people are free to postulate more exotic phenomena. And, you know, I think the jury's very much open.

FLATOW: All right. Sounds quite interesting. Thank you very much for taking time to talk with us. Good luck to you.

LORIMER: Oh, you're very welcome. Thank you.

FLATOW: You're welcome. Duncan Lorimer is the Woodburn professor of physics at West Virginia University in Morgantown, West Virginia.

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