14

None of the TRAPPIST-1 planets are "considered habitable"; we don't know nearly enough about them to say that (any news article which referred to the planets themselves as "habitable" needs firm correction). Three of them are within the habitable zone of the star, which is defined as the region around the star where liquid water could potentially be found on ...


11

Jupiter is about as large as a planet can get, physically. Suppose we slowly add hydrogen and helium to Jupiter, so slowly so as to keep it at more or less its current temperature. Surprisingly, it would get smaller. Jupiter is about as large as a planet can get. (There are exoplanets that are larger than Jupiter, but that's because they orbit so close to ...


8

The temperature estimate is based on no atmosphere. For instance, Earth, without our atmosphere, would have an average temperature of -20°C . The equator should be warmer, and any atmosphere will also add heat. Also, the objects are most likely tidally locked, which means that a single side of the planet will always face it's star, making it even warmer in ...


7

How do we have telescopes that are powerful enough to see nearby galaxies, such as Andromeda (M31), but are unable to see TRAPPIST-1 or the other exoplanets in its solar system in detail when TRAPPIST-1 is only 39 light years away? You don't need a telescope to see M31. It has an apparent magnitude of 3.4, which means it is easily visible to the naked eye, ...


4

Trappist-1 is difficult to see because it's not very big. In fact it's so small (~11% the radius, and ~8% the mass of the Sun), that if it were any less massive, it wouldn't be able to support fusion! Also, the human eye isn't very good at seeing much of the EM spectrum. So it's not emitting much visible light, BUT we can build tools to detect the ...


3

NASA has said roughly Earth sized. From this, reporters have written "Earth like". Some publications are even showing what look like photos of planets. These are likely generated with computers used for creating planets in games and films. As for life, we only know of one planet that developed life, and you can't build a statistical model from that. ...


3

In recent years, astronomers have been able to see (in their words, 'image directly') a few exoplanets. This is one of those: We have found about 2000 exoplanets so far, but we've only been able to directly image 22 of them as of 2017. Most exoplanets are found using indirect methods (e.g. by measuring the star's brightness over time, if there is a ...


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