NASA’s Kepler space telescope found a super Earth!
But don’t start planning your interstellar vacation just yet…
Hey guys!
Amy with you on DNews talking distant worlds that might be like our own.
The big exoplanet news from NASA last week is that the Kepler space telescope has found
the first near-Earth-size exoplanet!
Called Kepler-452b, we know this exoplanet is 60 percent larger in diameter than the
Earth and that it orbits in the habitable zone of a G2 star like our own sun.
The habitable zone is the region where it’s warm enough for liquid water to exist on the
surface.
But we don’t know the planet’s mass or its composition, so it might be rocky like
the Earth, or it might not be.
But we’re still calling it by the tantalizing name of super Earth.
Which sort of raises the larger question: what is a super Earth, and as we keep finding
different types of exoplanets, when should we actually be getting excited?
The most commonly found exoplanet types bear some similarity to our own giant planets,
Jupiter, Saturn, Uranus, and Neptune.
We hear a fair bit about Hot Jupiters.
These are gas giants like Jupiter that orbit their parent stars closer than Mercury orbits
our sun making them scorchingly hot.
There are also gas giants found around distant stars, Jupiter-like bodies orbiting at Jupiter-like
distances from their host stars.
Another neat exoplanet type that falls roughly under the gas giant banner is a group called
Chthonian Planets.
These are former gas giants who migrated so close to their parent stars that their atmospheres
have completely roasted away leaving behind a rocky or metallic core possibly covered
in molten lava.
Then there are the exoplanets classified as being somewhat Earth-like, somewhat being
the most important word.
The main type we hear about are Super-Earths, which sound like bigger, better version of
the Earth, but aren’t.
Super Earths have masses roughly 10 times greater than Earth’s and are ‘potentially’
rocky planets, so really, it’s just a mass distinction.
Some of these Super Earths could be gas dwarfs or Chthonian Planets.
Far more compelling are Exo Earths, planets with a similar mass and radius to the Earth
that have an atmosphere and also orbit their star’s habitable zone.
But, this doesn’t mean they’re Earthly.
Some models show both Venus and Mars living in our Sun’s habitable zone, albeit on the
fringes, and neither of those worlds are teeming with life like Earth is.
So an Exo Earth could be a distant sulfur-rich hell world!
And because so much of the search for life on other worlds is about finding water as
a necessary ingredient for life, a very interesting type of exoplanet is a Water World.
These planets are entirely covered in water, likely from surface ice that melted as they
drifted close to their parent stars.
Unfortunately, we haven’t actually found a true Earth orbiting another planet.
Earth-like, maybe, and planets with some similarities to Earth, yes, but we’re not moving to another
Earth anytime soon.
But that doesn't mean we should stop looking!
So, knowing that these exoplanet discoveries are more scientifically fascinating than indicative
of another world for us to live on, are you guys still excited about exoplanets?
While we’re asking space questions, should we be mining asteroids for precious metals?
Trace talks about one asteroid in particular that could be worth trillions