Astronomers have discovered two planets orbiting a star only 12.5 light-years away from Earth. The new planets are called TRAPPIST-1 and were found by using a telescope located in Chile. The new planets are much closer to their star than Earth is to the sun and may have water on their surface.
What is a planet?
A planet is a celestial body that, according to the International Astronomical Union (IAU), “is in orbit around the sun, is large enough to be spherical and has cleared its neighbourhood of other objects.” This definition excludes dwarf planets, which are smaller objects that orbit the sun but are not large enough to be considered planets.
Two new planets have been discovered orbiting a star only . light-years away from Earth. The planets were found using the radial velocity method, which uses the Doppler shift of spectral lines to determine the motion of a celestial body.
The first planet, called KOI-722b, has a mass about one-tenth that of Earth and is about twice as large. The second planet, called KOI-878b, has a mass about one-fifth that of Earth and is about the size of Jupiter. These planets are orbiting the star KOI-722b at a distance of about .5 AU (a distance equivalent to .5 light-years).
This discovery marks the first time that two planets have been discovered orbiting a star beyond our own galaxy. It also opens up new possibilities for studying how these planets formed and evolved.
What are the different types of planets?
There are a variety of different types of planets, each with its own unique features. Some planets are gas giants, like Jupiter, which is huge and has a lot of gas and dust orbiting around it. Other planets are smaller and rocky, like Earth.
The two new planets that have been discovered by international astronomers are both small and rocky. They are only about the size of Earth, which is why they were not spotted before.