The results are in, my friends:
NASA’s Transiting Exoplanet Survey Satellite has identified over 850 candidate exoplanets,
or planets outside our solar system, some of which have the potential to support life.
TESS, that hardworking gal, has been on this exoplanet-hunting mission for over a year. And
not only has this satellite exceeded the wildest dreams of the many scientists who use it to
find exoplanets, but it has also gathered unprecedented data on other astrophysical
phenomena, like exocomets and supernovae. TESS uses four large, specially designed cameras
that are able to scan the sky for stars outside our solar system. The cameras view overlapping
sectors of the sky for 27 days at a time, waiting to see the brightness from a star
blip in a certain way, an event called a transit. This indicates that something has passed in
front of the star, likely something that’s orbiting it…like a planet. This method is
called transit photometry, giving TESS the first part of its name.
And TESS double checks her work, too. That same object must pass by the same star,
causing the same blip, at least three times before being considered a candidate exoplanet.
Once potential exoplanets are identified, TESS then notifies astronomers on the ground to take
a closer look with their telescopes to confirm. TESS has already helped identify at least
28 confirmed new exoplanets, with more being confirmed every day. Scientists are looking at these planets to
see if any of them could potentially host alien life, but that’s not even the only
reason we’re interested in exoplanets. Some of them are what scientists are calling
‘missing link’ planets. These are somewhere in between smaller, rocky
planets, like our Earth and larger, gaseous planets like Neptune.
We don’t have any of these in-betweener planets in our solar system, so these ‘missing
links’ will be really exciting to study, since they’ll help us understand how these
kinds of planets form along-side rockier, more Earth-like worlds, and how these solar
systems evolve in the first place. TESS has pointed us to several solar systems
that look really promising, including three planets of particular interest that orbit
a relatively quiet star that’s relatively close to us.
When I say ‘quiet’, I don’t mean that it’s not blasting heavy death metal, I mean
that this star doesn’t flare very often, which makes it and the planets that move around
it easier to study. And when I say ‘close’, it is 73 light-years away, which sounds like
quite a ways, but is actually considered a close neighbor of ours!
The star in question is a red dwarf star called ‘TESS object of interest 270’, or TOI
270 for short. It’s got at least three planets orbiting it, and those are the ones we’re
looking at closely: TOI 270 B, C, and D. They’re all varying distances from the star,
with estimated temperatures ranging from a toasty 254 degrees Celsius to a nice and cool
66 degrees. One of the larger, gassier planets is identified
as a mini-Neptune—one of these missing link planets.
It was initially thought to be in the ‘habitable zone’ of its star, meaning it could have
liquid oceans and host life. But as scientists looked at it more closely,
they now think that TOI-270 D’s atmosphere is too thick, making the planet a greenhouse
that’s probably far too hot to host life. So that’s a bummer, but researchers still
want to probe the compositions and characteristics of the planets orbiting TOI-270.
Plus they think there may be other planets in this system, so we’re not giving up.
TOI-270 is just one of many systems that TESS has pointed us toward.
And while looking for star-planet systems like these, TESS was also able to observe
other exciting things outside our solar system, like exocomets
And because TESS looks at one particular patch of sky for so long, it can also observe stellar
events, like the beginnings of supernovae. Again, this means TESS can then tell ground
telescopes to take a closer look, which researchers hope will help us better understand the origins
of astronomical explosions of all different kinds. And get this—scientists can use
those observations to calculate how fast the universe is expanding.
Hopefully we’ll be able to get even closer looks at all the stuff that TESS has scouted
out for us when the James Webb Space Telescope eventually launches.
The JWST could even take measurements of the compositions of these exciting planets and
their atmospheres, telling us even more about whether these exoplanets could support life.
Thanks for the recon mission, TESS. We can’t wait to see what else you point out for us.
If you want to see just how close we are to launching the JWST, check out this video here,
and make sure you subscribe to Seeker for all your planetary discovery news. If you
have other planet questions for us, leave them down in the comments below and as always,
thanks for watching.