A Distant Planet Has An Extreme Forecast Astronomers have observed a planet orbiting a distant star that experiences temperature swings of hundreds of degrees in a matter of hours. Greg Laughlin, author on the Nature study, says weather models for the planet include glowing skies and 10,000 mile-per-hour winds.
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A Distant Planet Has An Extreme Forecast

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A Distant Planet Has An Extreme Forecast

A Distant Planet Has An Extreme Forecast

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And now, a trip a bit down the road to a planet called H8606b. It's in your star chart - your planet chart perhaps. It's impressive enough to be able to spot a planet orbiting around another star, this exosolar planet. But trying to predict the weather there - well, that's something else. And such weather temperature on that planet, swings of 700 degrees in just a few hours. Talk about your global warming. Joining me now is Greg Laughlin. He is a professor of astronomy and astrophysics at the University of California Santa Cruz, and one of the authors of a paper in this week's journal Nature that tries to do just that, modeling the atmospheric conditions on a very unusual planet. Welcome to the program.

Professor GREG LAUGHLIN (Astronomy and Astrophysics, University of California Santa Cruz): Hi.

FLATOW: Where is this planet?

Prof. LAUGHLIN: So this planet is about 190 light years from earth and so when we observe it, we're actually looking back to the Monroe administration. It's located in the sky close to the Big Dipper. So it's actually up in tonight's night sky, although it's a little too dim to see with the naked eye.

FLATOW: And is the first weather forecast for an exosolar planet?

Prof. LAUGHLIN: Well, this is the first forecast of a storm brewing on a planet outside our own solar system. The telescope that we used, the Spitzer space telescope, had observed sort of static weather patterns on a number of other planets orbiting other stars, but this is the first planet where we had predicted that a storm would occur and we are able to see the dramatic effects of that storm.

FLATOW: You mean, it was raining and thundering?

Mr. LAUGHLIN: No, it was heating up tremendously, and global shock waves were being driven around the planet.

FLATOW: Wow. Tell us a bit about this planet so we understand that storm.

Mr. LAUGHLIN: Yes. So this planet has an extremely eccentric orbit. The orbit looks more like that of a comet than what we would normally think of for a planet. It spends most of its time - it takes 111 days to go around its star. It spends most its time about 80 million miles from the star. That's about not quite the distance from the sun to the earth in that system, but then every 111 days, it comes screaming through for a very, very close encounter with its parent star. It comes to about 3 million miles from the surface of the star and during that time, if you're sitting on this planet, if you're floating above the hot surface, the hot gaseous surface of this planet, then you see the star filling something like a thousand times the area their own sun occupies in our sky, and so there's this brief period which lasts for a few hours of just tremendous heating on one hemisphere of the planet.

FLATOW: So, it's like zipping around the star like a comet.


FLATOW: And in that brief time, the temperature is skyrocketing.

Mr. LAUGHLIN: Yeah, so this temperature on the hemisphere of that is getting the brunt of the stellar radiation. It turns out, and we observed this, it spikes from roughly 980 degrees Fahrenheit all the way up to more than 2,000 degrees Fahrenheit. So, it kind of goes from a really hyper oven cleaning temperature up to sort of a natural gas flame temperature in a matter of hours. So it goes, you know, sort of it's an out of the frying pan into the fire kind of situation on this planet.

FLATOW: That's a new definition of global warming.

Mr. LAUGHLIN: (Laughing) High-speed global warming.

FLATOW: (Laughing) High speed. 1-800-989-8255. Talking with Greg Laughlin, the professor of astronomy and astrophysics at the University of California Santa Cruz. How did you discover all of this happening on that planet?

Mr. LAUGHLIN: Well, the planet has been known since 2001. The planet was discovered using this technique that astronomers have used to discover many planets around the stars, the Doppler Wobble method, and the Doppler Wobble method shows you what the orbital period is and what the orbital shape is. And we realized that the shape was so extreme and that this close encounter with the planet was so intense that the brewing storm on the surface should be visible using the Spitzer Space telescope, and so we're able to schedule the telescope to have a look.

FLATOW: What would the storm look like if, you know, we could see it?

Mr. LAUGHLIN: Well, if you were looking at this planet from a safe distance, you would see a blindingly bright crescent, and the crescent would have sort of a bluish cast. The starlight that hits the planet- the red and the yellow light tend to be absorbed, and the blue light is reflected. And then on the night side of the planet, the temperature is so hot that it would be glowing like red hot coals. So, if you've ever seen pictures of Jupiter, it has those sort of turbulent storms, and this would look something like that except that the storms themselves would be glowing with their own heat.

FLATOW: And this is a gas giant.

Mr. LAUGHLIN: It's a gas giant. Yeah, the planet is roughly the same size as Jupiter and it has about four times the mass of Jupiter.

FLATOW: Is it rotating quickly?

Mr. LAUGHLIN: It is rotating, not that quickly. Jupiter rotates in about 10 hours and this planet takes about 34 hours probably to rotate on its axis. So, its day is a bit longer than an earth day.

FLATOW: So, as it goes by, it's sort of barbequing.

Mr. LAUGHLIN: That's right. That's right. One hemisphere of the planet gets the brunt of the radiation and so it is certainly getting barbequed as it goes by.

FLATOW: And so, it doesn't even have enough time for it to spin around and get the other side done.

Mr. LAUGHLIN: That's right. The planet is actually, you know, over billions of years, has adjusted the length of its day so that one hemisphere takes the heat during these close encounters.

FLATOW: And it's the same side all the time?

Mr. LAUGHLIN: No, it's a different side each time because the orbital period isn't commensurate with the spin period, but nevertheless, each time it goes by, there is one hemisphere that takes the heat, and then that heat is distributed across the planet over, you know, the next days and weeks.

FLATOW: So, is all that gas just boiling and bubbling?

Mr. LAUGHLIN: Well, I wouldn't say it's boiling and bubbling. It's more that it's raising supersonically across the planet, so that the overall patterns have this sort of finger-like look and then they are moving at far faster than the speed of sound. So, if you're sitting in the atmosphere of this planet especially if you're on the night side, it's hot and unpleasant and then all of a sudden, you have this weather front go by at thousands of miles per hour where the temperature increases very, very rapidly.

FLATOW: Are there other planets in this solar system?

Mr. LAUGHLIN: There are almost certainly no planets in the inner region of this solar system. This planet would - its gravitational effect would slingshot any other planets that were close by out of the system. There could be planets further out, say at the distance of Jupiter from our own sun, but they haven't been detected yet.

FLATOW: Mm hmm. And is there any chance - is there any way we, here on earth, can actually look at this planet? Is it too far away?

Mr. LAUGHLIN: Well - so, an interesting thing is that the orbit is quite crazily elongated, and about six days after this close approach, then the planet actually passes between the star and the earth. And if the orbital geometry is just right, then the planet will actually block out some of the stars light as seen from the earth. This is called a planetary transit, and this has been observed for about 50 other planets outside of our own solar system. And so, if this occurs, it blocks out about one percent of the star's light, and it's something actually that amateur astronomers who have their technique down to a fine art can detect. And this transit, if it occurs, is going to be happening on the early morning of Valentine's Day. And so there will be astronomers all over the world watching to see whether or not the planet actually goes in front of the star. There's about 15 percent chance that the transit will occur.

FLATOW: We'll know who the true astronomers are on Valentine's.

Mr. LAUGHLIN: (Laughing) That's right.

FLATOW: (Laughing) 1-800-989-8255. Let's go to Mirali(ph) in - is it Novi, Michigan?

MIRALI (Caller): Yeah, that is right.


MIRALI: Thank you very much for taking my call. It's absolutely fantastic to hear the kind of stuff that they are discovering. My question is not as much about the astronomy as how I can get my kids, both in - one in elementary and one in middle school grade. My son especially is absolutely fascinated by the stars and he - I know he was fascinated by dinosaurs, and he wants to be a astro-paleontologist or whatever he calls it to be. So, I was kind of wondering, there are not many of these sources really that we could use. If you can point us in the right direction, that would be great.

FLATOW: Yeah. How do you get his kids or keep them interested? What should he do?

LAUGHLIN: Yeah. So, one - and sort of close to home thing that you can do, there's a Web site that we run, oklo.org, which is all about extrasolar planets, and it's sort of written at a level that interested people can, you know, sort of really relate to. And then for kids, I think that the NASA sites often have great stuff for kids as well. So, if you go to nasa.gov, for instance, and just follow the links there, you'll uncover quite a bit of fascinating stuff. When I was a kid, the public library, the books on astronomy at the public library were really what inspired me and I think now the Web can play that kind of role.

FLATOW: Good luck to you, Mirali. 1-800-989-8255. Do we have a name for this or just a number?

LAUGHLIN: The HD80606b, so I guess the name is b. Lower case b.

FLATOW: We're talking about planet lower case b in this hour on Talk of the Nation Science Friday from NPR News, talking with Greg Laughlin. I want to thank you very much, Greg, and good luck to you again. You'll be doing more observations. I know where you're going to be on Valentine's Day.

LAUGHLIN: That's right. Warm in bed while everyone else does the observing.

FLATOW: (Laughing) There you have it. Thanks a lot. Greg Laughlin is a professor of astronomy and astrophysics at the University of California Santa Cruz.

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