NASA announced the discovery ( http://
index.html#.VK01u2TF_90 ) of eight Earth-like
planets outside of our solar system, and one of
them has perhaps the best chance scientists have
found yet for harboring extraterrestrial life.
Kepler 438b is believed to be 12% larger than Earth
and lies within its sun’s “Goldilocks zone”—
meaning its distance from the star is just right for
potentially containing liquid water on its surface.
It’s 475 lightyears away from us, which is quite
close in the grand scheme of the universe but still
very, very far away ( http://www.popsci.com/
long-would-it-take-walk-light-year ) .
Launched in 2009, NASA’s $600 million Kepler
spacecraft surveys the Milky Way for Earth-like
planets orbiting other stars. To date, they’ve found
1,000 of them ( http://www.space.com/28105-
nasa-kepler-spacecraft-1000-exoplanets.html ) ,
and that’s only in our galaxy. Who knows how
many untold cousins of Earth there are elsewhere
in our galaxy and beyond?
It works, essentially, by observing the brightness
of stars in a fixed view. Analysts on Earth then
look for instances when an extrasolar planet
crosses in front of its star, causing the brightness
to dim. That might seem rather primitive, but a lot
can be gleaned from that dimming. It can tell us
the size of the planet, the shape of its orbit, its
distance from the star—and can give us a fairly
educated guess at what its composition is like.
That said, these planets are
too far away for us to directly observe or measure
things like atmosphere.
Astronomers at the Harvard–Smithsonian Center
for Astrophysics confirmed the existence of these
new planets ( http://www.cfa.harvard.edu/
news/2015-04 ) , using a computer program called
BLENDER to rule out the possibility of false
positives caused by stars crossing the view of
other stars. They published their findings in the
Astrophysical Journal ( http://
iopscience.iop.org/0004-637X/ ) .
The search for alien life will be boosted by the
TESS ( http://tess.gsfc.nasa.gov/ ) satellite,
launching in 2017, and the James Webb Telescope
James_Webb_Space_Telescope ) —Hubble’s
replacement—which will be put into orbit in 2018.
Author : Adam Epstein
URL : http://qz.com/322433/scientists-just-