SGU Episode 27

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SGU Episode 27
25th January 2006
(brief caption for the episode icon)
SGU 26                      SGU 28
Skeptical Rogues
S: Steven Novella
B: Bob Novella
J: Jay Novella
P: Perry DeAngelis
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Introduction

You're listening to the Skeptics' Guide to the Universe, your escape to reality. S: Hello and welcome to the Skeptic's Guide to the Universe. Today is Wednesday, January 25, 2006. This is your host, Steven Novella, President of the New England Skeptical Society. Joining me today are: Perry DeAngeles...

T: Hello, Everybody

S: Bob Novella...

B: Good Evening

S: And making a special reappearance, Jay Novella.

J: It's good to be back.

S: Yeah welcome back, Jay, it's good to have you again.

J: Yaaay.

laughter

T: Welcome, Jay. There's a rumor that Evan Berstein will be joining us little later.

S: He may be joining us a little bit later. He's not available at the moment. So there were a few news items to get things started. Evan sent me this one.

News Items

Most Earth-like Planet To Date Around Another Star (0:40)

S: He may be joining us a little bit later. He's not available at the moment. Um. So there were a few news items to get things started. Evan sent me this one: "The um most Earth-like planet discovered to date around another star. So..

J: Pretty cool.

S: It is very cool. Um. The reason why this is interesting because, a few months ago, this was one of the science or fictions that we did where the fake one was where astronomers found an Earth-like planet around a nearby star. um...

P: Once again Dr. Novella ahead of the curve.

S: And.

P: On these matters.

laughter

S: And this was one that we knew was coming because they're finding more and more Earth-like planets. By "Earth-like," I mean ... the size

P: The size and class?

S: No. haha. Umm.

B: M-class planets?

P: M-class, sorry.

S: Not yet that close. Just, you know, smaller and at a distance from the sun that is, you know, that resembles that of the Earth. Most of the planets that scientists and astronomers have discovered so far are uh, Jovian-like planets, they're gas giants and they're also very close. Like within, oh, what would be the orbit of Mercury. So very close to their to their stars. They're easier to see. The closer and bigger they are, the easier they are to see. But as they're refining their techniques, specifically, they're using a technique called microlensing to detect planets around stars. They're finding smaller and smaller planets farther and farther from their sun. The new record now ... um... and they just announced in the last day or so. There's a planet about 7. Um sorry

J: 5.5

S: 5.5 Earth-masses. So 5.5 times the mass of the earth. Mass of earth and

P: Does that mean five and a half times the gravity?

S: Yes, and 2.5 astronomical units from its star. An astronomical unit being the distance from the Earth to the Sun. So, 2.5 times the distance from the Earth to the Sun.

P: So why uhmm. Excuse me.

S: Go ahead.

P: So why basically um are uh, there are so many more gas giant type planets than planets like the Earth.

J: Well Perry, it's a situation where you're looking where the lights the best. That's really the only method we had when we were using the previosu method in determining the wobble that the planet exerted. The gravitational pull on the star. with the wobble; only a big planet close to the sun would produce that kind of effect, small planets can't. Now with the microlensing technique, now they are going to start seeing a lot more Earth-size planets. So that. So basically the answer to the question is that those were the only ones we could see using the old technique

S: So we don't know. We don't really know, because we haven't really been able to look for the smaller planets. We're hoping of course that we're gonna find a lot of Earth like planets around other stars. But it's also worth noting that htis partical star is a red giant. Uh. It's a lot cooler and dimmer than our sun. So the; although um this planet is only about 2 and half times the distance from its star as the Earth is from the Sun, it's very very cold. It's about as cold as Pluto. Um.

P: That's cold

S: yeah.

P: Hmmm

S: -364 degrees F. So ... Too cold to support liquid water and probably therefore life that we would recognize. So ...

P: What's the name of the planet?

S: Uh. The article does not have a name. It's has a designation: "OGLE 2005 BLG 39 LB."

P: Right

B: There could be life on that planet. I mean. There is .. You don't need photosynthesis. There could be chemosynthetic life. Look at Europa. You got tidal forces. Well, it depends. If there's a lot of um tidal forces acting on the planet, you would generate a lot of heat to melt the ice. You could create a liquid environment that could

S: Right.

P: You said surely there could be

Government and Wacky Science (55:40)

S: The Skeptics' Guide to the Universe is a production of the New England Skeptical Society. For more information about this and other episodes, visit our website at www.theness.com. 'Theorem' is performed by Kineto and is used with permission.

References