After sending robots to the moon, landing them on Mars and building its own space station, China is now eyeing the distant solar system. This month, scientists will release detailed plans for the country’s first mission to discover an exoplanet.
The mission is designed to survey planets in other parts of the Milky Way outside our solar system, with the goal of finding the first Earth-like planet that orbits the star’s habitable zone like the sun. Astronomers think such a planet, known as Earth 2.0, would have the right conditions for liquid water—and possibly even life—to exist.
More than 5,000 exoplanets have been discovered in the Milky Way, most of which were used by NASA’s Kepler telescope, which ran for nine years before running out of fuel in 2018. Some of these planets are terrestrial rocky celestial stars orbiting small red dwarfs, but none fit the definition of Earth 2.0.
Jessie Christiansen, an astrophysicist at NASA’s Exoplanet Science Institute in California, said that with current technology and telescopes, it is difficult to find small Earth-like planets when their host stars are 1 million times heavier and 1 billion times brighter. Signal. Pasadena Institute of Technology.
China’s Earth 2.0 plan hopes to change that. It will be funded by the Chinese Academy of Sciences and is wrapping up its early design phase. If the design passes a panel of experts in June, the mission team will receive funding to begin building the satellite. The team plans to launch the spacecraft on a Long March rocket by the end of 2026.
The Earth 2.0 satellite is designed to carry seven telescopes that can observe the sky for four years. Six of the telescopes will work together to survey the Cygnus-Lyra constellation, the same patch of sky that Kepler has searched. “The Kepler field is an easy-to-achieve result because we get very good data from there,” said astronomer Jiang Ge, who is in charge of the Earth 2.0 mission at the Shanghai Observatory of the Chinese Academy of Sciences.
The telescope will look for exoplanets by detecting tiny changes in the star’s brightness that indicate a planet has passed in front of it. Using multiple small telescopes at the same time gives scientists a wider field of view than a single large telescope like Kepler. Together, Earth 2.0’s six telescopes will look at about 1.2 million stars in a 500-square-degree sky, which is about five times wider than Kepler’s field of view. Meanwhile, Earth 2.0 will be able to observe dimmer, farther stars than NASA’s Transiting Exoplanet Survey Satellite (TESS), which surveys bright stars near Earth.
“Our satellite could be 10 to 15 times more powerful than NASA’s Kepler telescope in its sky-measuring capabilities,” Ge said.
The satellite’s seventh instrument will be a gravitational microlensing telescope to measure roaming planets — free-roaming objects that don’t orbit any stars — as well as distant exoplanets, similar to Neptune. It detects changes in starlight as the gravity of a planet or star distorts the light of the background star it is passing by. The telescope will be aimed at the center of the Milky Way, where a large number of stars are located. If successfully launched, it will be the first gravitational microlensing telescope to operate in space, Ge said.
“Our satellite can basically do a census and identify exoplanets of different sizes, masses and ages. This mission will provide a large sample of exoplanets for future research,” he said. A1A2A3A4A5A6A7A8A9A10A11A12A13A14A15
Double the data
NASA launched Kepler in 2009 to find out how common Earth-like planets are in the Milky Way. To confirm that an exoplanet is similar to Earth, astronomers need to measure the time it takes to orbit the sun. Such planets should have an orbital period similar to Earth’s and pass through their sun about once a year. Astrophysicist Chelsea Huang of the University of Southern Queensland in Toowoomba said scientists needed at least three transits to calculate the precise orbital period, which required about three years of data, and sometimes even more if there were data gaps. long time.
But four years after the Kepler mission, parts of the instrument malfunctioned, preventing the telescope from staring at an area of the sky for long periods of time. Kepler is on the cusp of finding some truly Earth-like planets, said Huang, who was a data modeling consultant on the Earth 2.0 team.
With Earth 2.0, astronomers have another four years of data that, combined with Kepler’s observations, could help confirm which exoplanets are truly Earth-like. “I’m very excited about the prospect of returning to the field of Kepler,” said Christiansen, who hopes to study Earth 2.0 data, if they become available.