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We keep finding planets HUNDREDS of them! But once we find a planet... then what do
we do with it?
Hey everybody, Trace here with your Weekly DNews Space Update. The first exoplanet was
discovered in 1992, and since then we've confirmed 1800 more. But discerning anything about these
planets is pretty difficult, because they're so far away.
To simplify the discovery of these exoplanets NASA launched a planet-hunting telescope named
after the famous 17th century astronomer Johannes Kepler. This week, scientists at NASA announced
Kepler's namesake, in spite of being broken, discovered 715 new planets! To date, they've
found indications of over 3,500 planets, but what do we KNOW about these alien worlds?
Well, not a lot. It's really difficult to FIND planets orbiting far away stars and we've
never seen one up close. The farthest camera from our sun is Voyager 1 -- and it's barely
passed out of our solar system. What we can usually determine is the number of planets
orbiting a star, the masses of those planets and their relative sizes. The research depends
on excellent observation and timing paired with state of the art equipment.
Armed with all of these, researchers at CalTech discovered water on a planet 51 light-years
from Earth. It's called Tau Boötis b. Though scientists have found water vapor on planets
before, the method these researchers used is new! Tau Boötis b is what's called a "hot
Jupiter" because it is close to its sun, and about the size of our Jupiter. Prior to this
new method, we had to be watching at the moment one of these gas giants passed in front of
its star in order to perceive evidence of water. If we missed it, or were at the wrong
angle -- no dice.
But now, astronomers at the Keck Observatory in Hawaii are using the Near Infrared Echelle
Spectrograph to determine the glow of a planet's atmosphere to discern the light wavelengths
emitted by different molecules. In other words, they can now look at a planet's glow to determine
if a planet has WATER.
Spectrographs are used by chemists; you've probably seen them on CSI and other forensics
shows. They use thing learned in 20th century chemistry to analyze the chemical fingerprint
molecules. For example: atoms of oxygen, sodium or carbon absorb or reflect specific wavelengths
of light -- so every molecule has its own fingerprint of colors and hues, and by using
infrared, this spectrograph reveals even MORE information. Using this new technique, astronomers
can determine which elements are in the atmosphere of a planet light-years away just by pointing
their telescope at it.. MIND. BLOWN.
I mean, this equipment is pretty standard science fare, but for astronomers looking
at exoplanets, it's pretty cool. Using this new method we can point telescopes at planets
all over the visible universe and determine what KIND of planet that is. If we point it
at those in green-zones -- or a human habitable planet zone -- and find water, nitrogen and
oxygen in the atmosphere, we'll be able to make a map of planets likely to support Earth-like
life!
Astronomy is fantastic, old school science. I looked through a telescope for the first
time when I was a kid and it was breathtaking...
Have you ever tried it? Tell us below in the comments and thanks for watching! See you
next week for another Space Friday.