TESS Planet Hunter Finds Its 1st Earth-Size World in 'Habitable Zone'

When launched TESS (Transiting Exoplanet Survey Satellite) had a mission goal of finding Earth sized planets , now it's starting to deliver on that with the discovery of it's first Earth sized planet orbiting a Red Dwarf Star just 100 light years away (I know .. just ) , but nevertheless it's in our back yard.

TOI 700 d, the outermost known planet in the system, is the really intriguing one. It's just 20% larger than Earth and completes one orbit every 37 days. The alien world receives 86% of the stellar energy that Earth gets from the sun, putting TOI 700 d in the habitable zone (at least as it's traditionally defined), discovery team members said.

All three planets may be tidally locked to TOI 700, always showing it the same face just as Earth's moon only ever shows us its near side. But tidal locking doesn't necessarily preclude the possibility of life on an alien world, astronomers say. And there's more good news along these lines regarding TOI 700.

"In 11 months of data, we saw no flares from the star, which improves the chances TOI 700 d is habitable and makes it easier to model its atmospheric and surface conditions," discovery team leader Emily Gilbert, a graduate student at the University of Chicago, said in the same statement.
www.space.com...

Each day a new discovery and with the new hardware going up we're getting closer to answering the question.

Meh. Most stars have planetary systems, from what I have seen has been gathered in the past couple of decades of research.

Read an article awhile ago too that explains what one really needs to be looking for if they want to find earth-like planets, and the conditions are very extreme.

A few examples I recall off hand...


Most stars are binary, meaning one star has another star that orbits it. The sun even in our part of the Milky Way seems to be pretty unique in that it is a single no binary system. Something important. For unlike what you read or watch in fantasy stories binary stars would wreck havoc with the stability of the orbit of an earth-like planet.

Most planetary systems discovered have elliptical orbits, the sun's planetary system is circular.

Most planetary systems discovered have the larger planets in the inner orbits. Imagine a planet like Jupiter being in an inner orbit near the earth. That too would play havoc with the earth's stability.

The way our solar system is designed the denser smaller planets are in the inner orbits, while the larger less dense gaseous planets are in the outer edges. These act as one of various barriers to extra-planetary debris entering our system. The act as magnets drawing debris to themselves, a shield of sorts for the inner planets.

The earth orbits a star classified as a yellow dwarf. Most stars in existence, in the Milky Way are red dwarfs much too small, and the others are much to big.

The sun is a heavy element rich star. The heavy elements found in our solar system, of which are needed for biological life can only be found in heavy element rich star systems. Of which there are few. Heavy elements can only be created in the furnaces of red giants as they end their life-spans as red giants and consume themselves. Our solar system is the result of a red giant explosion many billions of years ago, and a subsequent reforming of heavy elements to both form a star with nuclear fusion and its planetary system.

Our solar system in on the outer edges of the Milky Way, in a fairly unpopulated spiral arm. Nearer you get to the center of the galaxy the more dense stars are. Nearing the center of the galaxy there is so much radiation biological life on earth simply would not be possible.

Our earth is situated in exactly the right orbit from our star so that it is neither too hot or too cold. The earth's natural satellite, the moon, is the exact right size, and distance from the earth to keep its axis stable at 23.4 degrees, which not only allows for the seasons, but keeps the earth from wobbling, which would cause huge tidal waves, extreme earthquakes, and extreme variations in temperatures which would also be a huge hindrance for life. It is also what keeps the oceans in check.

There are far more things that just these I remember off the top of my head. The list is really extremely long. These are some of the things I remember.

If people were sincere about finding life like our own they would have to turn their attention to systems that could actually sustain life like ours. And the check-list would really narrow down the scope an extreme degree. Perhaps it may even be impossible, who knows. Perhaps there are other systems just right like our own. It is indeed an unfathomably huge universe.

From our puny perspective in the scheme of things, our wonderful blue sphere is the only one we know in the universe that has life. Personally, I doubt that is going to change for a long time.

a reply to: SimpleIdea

"From our puny perspective in the scheme of things, our wonderful blue sphere is the only one we know in the universe that has life. Personally, I doubt that is going to change for a long time."

They should be able to detect the chemical composition of planets atmosphere within the next 10 years ( Webb telescope, European ELT etc) which should tell us which planets are likely to harbor life. If they detect O2 in the atmosphere of an exo planet it be a very positive bio-signature.

Then I guess, SETI could concentrate their radio telescopes at those planets for radio signals.

originally posted by: glend
a reply to: SimpleIdea

"From our puny perspective in the scheme of things, our wonderful blue sphere is the only one we know in the universe that has life. Personally, I doubt that is going to change for a long time."

They should be able to detect the chemical composition of planets atmosphere within the next 10 years ( Webb telescope, European ELT etc) which should tell us which planets are likely to harbor life. If they detect O2 in the atmosphere of an exo planet it be a very positive bio-signature.

Then I guess, SETI could concentrate their radio telescopes at those planets for radio signals.

Two things,
One, just because there is O2 in an atmosphere, does not mean that life as we know it is likely there, as there are plenty of other factors involving whether the atmosphere can produce or have organic compounds, and whether or not they are O2 based or not, which brings me to my second point,
there is a possibility that life outside of our planet is not O2 based, it could be CH4 (Methane) based like what we have with bacteria huddled around thermal vents, and if the universe is infinite as some people say, then the chances of that kind of life along with others kinds of life such as happening somewhere else is guaranteed if we just search hard enough based the infinite monkey theorem and how there are infinite combinations,
and even if the universe is finite, we have evidence in seeing GN-z11 (which is the furthest known galaxy ever observed) that the universe is PRETTY big, even with the expansion effect in play (I'll link some sources below for further explanation). So when all is said and done, there is a good chance there is life of SOME kind out there.

Sources
About the infinite monkey theorem: en.wikipedia.org...
About specialized bacteria near thermal vents: oceana.org...
About hypothetical types of biochemistry:en.wikipedia.org...
About GN-z11:www.nasa.gov...
About the expansion effect:en.wikipedia.org...