Brave New Worlds

Fourteen years ago, we only knew of one solar system in the universe — our own. Since then, scientists have discovered about a hundred planets orbiting other stars.

Steve Vogt: The one thing I know, that we will know before I die, is how unique our solar system is. Are we an oddball or are we commonplace?

That’s Steve Vogt, an astronomer and member of the California and Carnegie Planet Search, based in Santa Cruz. Their team has discovered over half of the known extrasolar planets by looking for stars that wobble in response to their planets’ gravity Since they never actually see the planets they discover, astronomers can’t say much about their size and composition.

But if astronomers could see a star become dimmer as a planet goes across its face, they might be able to say whether it’s rocky like Earth or gaseous like Jupiter. So far, only one planet has been seen passing directly between us and its star. Dr. Vogt’s team caught such a passage in 1999.

Steve Vogt: It’s a wonderful feeling, very exciting. And that was, sort of like, the first and only transiting planet out of some two thousand stars that we’ve looked at now for planets, and that’s about what we expected . . . And we’re looking hard to find another one . . . Maybe one of these days we’ll get lucky.

Excerpts from Interview with Dr. Vogt:

“The one thing I know, that we will know before I die, is how, how unique our solar system is. Is our kind of solar system with the big gas giants like Jupiter, Saturn, Neptune, and Uranus in the wide swinging orbits, and the earths, and the mars, . . . in the closer orbits, is that a common or an anonymous occurrence And so we’d like to have a good idea of what fraction of stars like our sun make the kind of solar system that we live in; are we an odd ball or are we common place and that’ll give us a really good idea then of how likely that we’ll find earths in habitable zones around other stars.”

“It was a wonderful feeling, very exciting. And that was, sort of like, the first and only planet out of some two thousand stars that we’ve looked at now for, for, planets, and that’s about what we expected . . . we’re looking hard to find another one . . .  Maybe one of these days we’ll get lucky.”

[Author’s Comments: From what I’ve gathered this field is undergoing two different general trends. One is the perfection of existing technology to learn more about smaller planets. The other is the sprouting of a whole bunch of new methods for finding planets. Finding solar systems like our own seems like a matter of time rather than feasibility. One potential method that I was interested in was using other stars as gravitational lens to find planets. It hasn’t panned out yet. Dr. Vogt also thought that we might see a picture of an earthlike planet before he dies … if NASA’s projects do their job and astronomers find likely candidates.]

“We’re able to easily detect Jupiter class, or even Saturn planets now, but we’d like to be able to push down routinely to get to things that are even a lot smaller than that, to things that are 10-15 times the size of the Earth – things that are starting to look like big rocks rather than big gasbags.”

“Planets are now just popping out the woodwork left and right, and its sort of like, well it’s no big deal, everybody can find planets. It took decades, man decades, of effort to develop the techniques to do this.”

“One is to keep the radial velocity database going for the next 5-10 years so that we can find planets that are in orbits like our Jupiter, that are in orbits that are 5 times as big as the earth’s orbit that have 11-12 year periods, because those are places where we’ll find solar systems like our own, those are places where we’ll find earthlike planets in a habitable zone. An earthlike planet that could have oceans, and water, and life . . . that will take four to five years, and we already have candidates that we know to be true Jupiters and its just a matter of time . . . ”

“”In certain circumstances you happen to be in the plane of the orbit and when your near to the plane of the orbit, as the planet comes around in front of the star, it actually crosses the disk of the star, we call that a transit, and you can actually see the planet cross the disk of the star, we can’t resolve the star, so there’s really nothing we can see like to image, but we can see a drop in the brightness of the starlight for a few hours as the planet moves across the disk of the star and then across to the other side.”

“So far we have one planet that we’ve discovered transiting. We’ve got a number of candidates but none of them have panned out so far.”

What you have in your mind?