The website of British magazine Nature pointed out in a report on April 12 that after sending robots to the moon, landing robots on Mars and building their own space station, China has set its sights on the distant solar system. In April, Chinese scientists will announce the detailed plan of the first exoplanet exploration mission.

According to the plan, the mission called “earth 2.0” will be launched in 2026 to investigate planets outside the solar system in the Milky way and find the first earth like planet active in the habitable area of sun like stars. Astronomers believe that such a “earth 2.0” planet will have conditions suitable for the existence of liquid water (or even life).

emerge as the times require

Scientists have found more than 5000 exoplanets in the Milky way, most of which were discovered by NASA’s Kepler space telescope. The Kepler telescope was launched in 2009. Its core goal is to find habitable earth like planets orbiting sun like stars. After nine years of operation, the telescope ran out of fuel in 2018.

Some of the exoplanets discovered by Kepler telescope are earth like rocky objects orbiting small red dwarfs, but none of them meet the definition of “earth 2.0”.

Astrophysicist Jesse Christensen of NASA’s Institute of exoplanet science at the California Institute of Technology said that under the current technology and telescope conditions, it is difficult to detect the signal of earth like asteroids.

“Nature” reported that China is planning a mission called “earth 2.0”, hoping to change this situation. It will be funded by the Chinese Academy of Sciences and the early task design phase is about to be completed. If the design passes the review of the expert group in June this year, the task force will receive funds to start the construction of the satellite. The team plans to use the long march rocket to launch the satellite by the end of 2026.

7 “eyes”

The earth 2.0 satellite will carry seven telescopes for a four-year mission. Six of them will work together to observe Cygnus and Lyra, and the Kepler telescope has also detected the same sky.

The six telescopes will use the “transit star method” to search for traces of exoplanets. The so-called “transit star method” refers to the weak luminosity change on the stellar surface caused by the planet passing through the stellar surface. Kepler mainly uses the “transit star method” to find exoplanets. However, compared with a single large telescope such as Kepler, the simultaneous use of multiple small telescopes can provide scientists with a wider field of vision. The six earth 2.0 telescopes will jointly observe about 1.2 million stars within 500 square degrees, which is about five times wider than Kepler’s field of view. At the same time, earth 2.0 will be able to observe darker and more distant stars than those detected by NASA’s transit exoplanet survey satellite (TESS). Tess was launched in 2018 to investigate bright stars near the earth.

Ge Jian, the head of the “earth 2.0” project and a researcher at the Shanghai Observatory of the Chinese Academy of Sciences, said: “the superposition of six telescopes can obtain five times the field of view of the Kepler telescope, and then use very low-noise instruments to obtain an observation depth of more than two to three times that of Kepler. The search ability of our detector will be 10 to 15 times that of the Kepler mission.”

The seventh instrument on the satellite will be a micro gravitational lens telescope to detect wandering planets (free roaming objects that do not orbit any stars) and Neptune like exoplanets far away from their stars. When the distant starlight passes through the exoplanet system, it is deflected and amplified by the planet’s gravity. The micro gravitational lens telescope can detect the exoplanet.

Ge Jian said the telescope will aim at the center of the Milky Way galaxy, where there are a large number of stars. If the launch is successful, it will be the first micro gravitational lens telescope to operate in space. “Our satellites can basically identify exoplanets of different sizes, masses and ages, providing rich data for future exoplanet research,” he said

Data doubling

To confirm that an exoplanet is an earth like planet, astronomers need to measure the time it takes to rotate around its main star. The orbital period of such a planet should be similar to that of the earth, rotating around its main star once a year. Huang Xu, an astrophysicist at the University of South Queensland in Australia, explained that scientists need to traverse stars at least three times to calculate an accurate orbital period, which takes three years or more.

But four years after the Kepler mission began, some parts failed, making it unable to stare at the same area of the sky for a long time. Huang Xu, who once served as a data simulation consultant in the “earth 2.0” team, said that with “earth 2.0”, astronomers can obtain data for another four years. The data provided by “earth 2.0” can be used in combination with the observation results provided by Kepler to help scientists confirm which exoplanets are real earth like planets. Christensen is excited about this and hopes to have the opportunity to study the data provided by earth 2.0.

Ge Jian hopes to find more than a dozen “earth 2.0” exoplanets. He plans to publish the data within a year or two after collecting them. At present, the “earth 2.0” team has about 300 scientists and engineers, most of them from China, but Ge Jian hopes to have more astronomers to join. He said: “earth 2.0 provides an opportunity for better international cooperation.”

The website of British magazine Nature pointed out in a report on April 12 that after sending robots to the moon, landing robots on Mars and building their own space station, China has set its sights on the distant solar system. In April, Chinese scientists will announce the detailed plan of the first exoplanet exploration mission.

According to the plan, the mission called “earth 2.0” will be launched in 2026 to investigate planets outside the solar system in the Milky way and find the first earth like planet active in the habitable area of sun like stars. Astronomers believe that such a “earth 2.0” planet will have conditions suitable for the existence of liquid water (or even life).

emerge as the times require

Scientists have found more than 5000 exoplanets in the Milky way, most of which were discovered by NASA’s Kepler space telescope. The Kepler telescope was launched in 2009. Its core goal is to find habitable earth like planets orbiting sun like stars. After nine years of operation, the telescope ran out of fuel in 2018.

Some of the exoplanets discovered by Kepler telescope are earth like rocky objects orbiting small red dwarfs, but none of them meet the definition of “earth 2.0”.

Astrophysicist Jesse Christensen of NASA’s Institute of exoplanet science at the California Institute of Technology said that under the current technology and telescope conditions, it is difficult to detect the signal of earth like asteroids.

“Nature” reported that China is planning a mission called “earth 2.0”, hoping to change this situation. It will be funded by the Chinese Academy of Sciences and the early task design phase is about to be completed. If the design passes the review of the expert group in June this year, the task force will receive funds to start the construction of the satellite. The team plans to use the long march rocket to launch the satellite by the end of 2026.

7 “eyes”

The earth 2.0 satellite will carry seven telescopes for a four-year mission. Six of them will work together to observe Cygnus and Lyra, and the Kepler telescope has also detected the same sky.

The six telescopes will use the “transit star method” to search for traces of exoplanets. The so-called “transit star method” refers to the weak luminosity change on the stellar surface caused by the planet passing through the stellar surface. Kepler mainly uses the “transit star method” to find exoplanets. However, compared with a single large telescope such as Kepler, the simultaneous use of multiple small telescopes can provide scientists with a wider field of vision. The six earth 2.0 telescopes will jointly observe about 1.2 million stars within 500 square degrees, which is about five times wider than Kepler’s field of view. At the same time, earth 2.0 will be able to observe darker and more distant stars than those detected by NASA’s transit exoplanet survey satellite (TESS). Tess was launched in 2018 to investigate bright stars near the earth.

Ge Jian, the head of the “earth 2.0” project and a researcher at the Shanghai Observatory of the Chinese Academy of Sciences, said: “the superposition of six telescopes can obtain five times the field of view of the Kepler telescope, and then use very low-noise instruments to obtain an observation depth of more than two to three times that of Kepler. The search ability of our detector will be 10 to 15 times that of the Kepler mission.”

The seventh instrument on the satellite will be a micro gravitational lens telescope to detect wandering planets (free roaming objects that do not orbit any stars) and Neptune like exoplanets far away from their stars. When the distant starlight passes through the exoplanet system, it is deflected and amplified by the planet’s gravity. The micro gravitational lens telescope can detect the exoplanet.

Ge Jian said the telescope will aim at the center of the Milky Way galaxy, where there are a large number of stars. If the launch is successful, it will be the first micro gravitational lens telescope to operate in space. “Our satellites can basically identify exoplanets of different sizes, masses and ages, providing rich data for future exoplanet research,” he said

Data doubling

To confirm that an exoplanet is an earth like planet, astronomers need to measure the time it takes to rotate around its main star. The orbital period of such a planet should be similar to that of the earth, rotating around its main star once a year. Huang Xu, an astrophysicist at the University of South Queensland in Australia, explained that scientists need to traverse stars at least three times to calculate an accurate orbital period, which takes three years or more.

But four years after the Kepler mission began, some parts failed, making it unable to stare at the same area of the sky for a long time. Huang Xu, who once served as a data simulation consultant in the “earth 2.0” team, said that with “earth 2.0”, astronomers can obtain data for another four years. The data provided by “earth 2.0” can be used in combination with the observation results provided by Kepler to help scientists confirm which exoplanets are real earth like planets. Christensen is excited about this and hopes to have the opportunity to study the data provided by earth 2.0.

Ge Jian hopes to find more than a dozen “earth 2.0” exoplanets. He plans to publish the data within a year or two after collecting them. At present, the “earth 2.0” team has about 300 scientists and engineers, most of them from China, but Ge Jian hopes to have more astronomers to join. He said: “earth 2.0 provides an opportunity for better international cooperation.”