NASA | Hubble & Exoplanets

Uploaded by NASAexplorer on 09.09.2010

Marc Kuchner: I don't know--when I was growing up, there was no such thing as planets around
other stars. If you were to talk about it at a scientific meeting, people would laugh at you.
Not that I was talking at scientific meetings when I was in high school, but
so I'm told.
Music swells

Jennifer Wiseman: Planets are very small compared
to the stars that they orbit. They're also very dim.
Marc Kuchner: For example, the Earth is ten billion times fainter
than the Sun--ten billion times fainter.
Jennifer Wiseman: It's kind of like
trying to see a firefly next to a lighthouse.
It gets lost in the glare.
Marc Kuchner: The Hubble Space Telescope takes pictures of nearby
stars and uses a special tool called a coronagraph
and the coronagraph blocks out the light from the star.
Aki Roberge: It's a fancy way of putting your thumb over the star, basically, so you can see
something faint that is right next to it.
Jennifer Wiseman: We can also use Hubble and other telescopes to study
regions where we think planets might be forming.
Marc Kuchner: We see in images from Hubble, we see these rings of dust
around nearby stars.
Aki Roberge: Well what I observe
with Hubble are those disks. Those disks of gas
and dust around the young stars, in which we think the dust grains
are starting to clump together and build up into pebbles,
rocks, asteroids, comets, Earths.
Jennifer Wiseman: We're finding baby solar systems by using
Hubble and other telescopes, including sort of ground-based radio telescopes
that can peer into these disks around stars and
see young planets or regions where young planetary systems
are forming.
Aki Roberge: The study of exoplanets is
only a little over 15 years old.
Marc Kuchner: We've discovered more
than 400 extrasolar planets now.
Aki Roberge: You know, we're still just beginning to
understand how the processes that formed
our own solar system, also formed these really diverse
types of planets. I think the thing that excites me
most is just the basic discovery of what
exists. You know, what's out there. Waterworlds, carbon planets?
It sounds like science fiction, but not really.
Not anymore.
Marc Kuchner: Why did life arise on
Earth instead of somewhere else?
I mean if there's another planet that could have life on it,
why aren't we there?