New interstellar immigrants

China is planning its first satellite mission to go beyond the solar system and look for exoplanets orbiting sun-like stars in the Milky Way.

The mission goal is to find the first earth-like planet orbiting a sun-like star in the livable zone. The exoplanet known as Earth 2.0 will have conditions suitable for the existence of liquid water and may give birth to life.

Although NASA's Kepler telescope discovered more than 5,000 exoplanets before the fuel ran out in 2065,438+08, none of them met the definition of Earth 2.0. Searching for exoplanets is discovered by observing the brightness of stars. When the planet passes in front of the star, the brightness of the star will darken.

Candidates for Earth 2.0 have an orbital period of about one year, so they pass in front of their stars once a year. It takes three passes to determine the orbit correctly, so it takes more than three years to observe the same star.

Kepler's early mission broke down, which made it impossible to stare at the same place for a long time, so it was impossible to determine the exact orbit of the alien planet it discovered. This new mission will use more telescopes to search the same sky and collect more data to calculate the orbit. With Earth 2.0, astronomers can get four more years of data, which, combined with Kepler's observations, can help to confirm which exoplanets are indeed similar to Earth.