Rodolfo Frino
Rainbow solar system
Hypothetical extrasolar system.
"An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun. Starting in 1988, and as of 1 January 2017, there have been 3,557 exoplanets in 2,668 planetary systems and 601 multiple planetary systems confirmed. HARPS (since 2004) has discovered about a hundred exoplanets while the Kepler space telescope (since 2009) has found more than two thousand. Kepler has also detected a few thousand candidate planets, of which about 11% may be false positives. On average, there is at least one planet per star, with a percentage having multiple planets. About 1 in 5 Sun-like stars [a] have an "Earth-sized" [b] planet in the habitable zone. [c] Assuming there are 200 billion stars in the Milky Way, [d] one can hypothesize that there are 11 billion potentially habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included.
Besides exoplanets, there are also rogue planets, which do not orbit any star and which tend to be considered separately, especially if they are gas giants, in which case they are often counted, like WISE 0855−0714, as sub-brown dwarfs. The rogue planets in the Milky Way possibly number in the billions (or more)." (Text credits: Wikipedia).
Rainbow solar system
Hypothetical extrasolar system.
"An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun. Starting in 1988, and as of 1 January 2017, there have been 3,557 exoplanets in 2,668 planetary systems and 601 multiple planetary systems confirmed. HARPS (since 2004) has discovered about a hundred exoplanets while the Kepler space telescope (since 2009) has found more than two thousand. Kepler has also detected a few thousand candidate planets, of which about 11% may be false positives. On average, there is at least one planet per star, with a percentage having multiple planets. About 1 in 5 Sun-like stars [a] have an "Earth-sized" [b] planet in the habitable zone. [c] Assuming there are 200 billion stars in the Milky Way, [d] one can hypothesize that there are 11 billion potentially habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included.
Besides exoplanets, there are also rogue planets, which do not orbit any star and which tend to be considered separately, especially if they are gas giants, in which case they are often counted, like WISE 0855−0714, as sub-brown dwarfs. The rogue planets in the Milky Way possibly number in the billions (or more)." (Text credits: Wikipedia).