there life elsewhere in the Universe? Until just recently,
scientists didn't even know if there were planets beyond our
own solar system, much less habitable ones. But, in the last
decade, astronomers have found more than 30 of these extrasolar
planets by looking for the slight gravitational wobble they
induce in their parent stars.
At the Harvard-Smithsonian Center for Astrophysics, David
Latham and his colleagues are pioneering a more direct
method of extrasolar planet detection. In "Alien Worlds,"
Latham's team looks for stars that dim periodically, indicating
the transit of a planet between the star and Earth-bound observers.
The amount of light blocked reveals the diameter of the planet.
The frequency of the dimming provides the planet's orbit.
revealing as this technique is, it requires a lot of patience.
As Latham tells Alan Alda, "you have to look at a lot
of stars to see the ones that are lined up just right to see
a transit." The researchers' perseverance has paid off.
After seven years of work, Latham's team has just made the
first ever observation of an extrasolar planet passing in
front of a distant star.
powerful Keck Telescope, high atop a Hawaiian volcano
researchers aren't waiting to find a planet. Paul Horowitz
is working under the assumption intelligent life is already
out there- and looking for us. Horowitz scans the skies for
regular flashes of light; possible signals from one intelligent
civilization to another. Everyone acknowledges it's a longshot,
but it's just one more creative attempt at answering the question,
"Are we alone?"
more on this topic, see the web feature:
Anybody Out There?