The Sun is not the only star with a planetary system. All other planets that orbit other stars are called extra-solar planets, or exoplanet for short. Exoplanets have been detected around stars of a range of types and ages, suggesting that planet formation is a robust process Some exoplanets are similar to the. Earth in terms of size, surface temperature, atmosphere, etc. And they may even be in the habitable zone. Life may be found in the future on exoplanets. Astronomers are working on