A team of Chinese researchers proposes to launch a space telescope to search for a copy of Earth within 32 light-years of the solar system.
Simulation of an Earth-like exoplanet. Image: Sci Tech Daily
Of the more than 5,000 discovered exoplanets, many are much larger than Earth or are located in habitable zones around stars that are smaller and cooler than the Sun. The Near Habitable Exoplanet Survey (CHES) mission, designed and developed by Ji’s research team for nearly a decade, aims to track around 100 Sun-like stars within 32 light-years of the Sun. solar system. This mission will measure small changes in the star’s relative position in the sky in search of an Earth-like planet orbiting.
Findings from the telescope could help answer the question “whether life exists only on Earth or exists in the universe,” said project leader Ji Jianghui, a researcher at Purple Mountain Observatory in California. Chinese Academy of Sciences (CAS) in Nanjing.
The planet and host star affect each other’s motions due to the gravitational attraction. If scientists detect slight periodic oscillations in the host star’s position, then a planet orbiting it is more likely. According to Ji, such a planet-detection method is highly effective because “it can detect any Earth-like planets that exist in or near the star’s habitable zone”. Compared to CHES, exoplanet hunting missions such as NASA’s Kepler and TESS telescopes can only observe planets whose orbits are aligned with the line of sight from Earth.
The CHES project is expected to discover about 50 Earth-like or super-Earth-like exoplanets. The astrometric method that CHES uses is a fundamental technique in astronomy, but has only been able to be applied to exoplanet studies in recent years thanks to technological advances, according to Wang Wei, science at the National Astronomical Observatory of China in Beijing. CHES needs to measure the oscillation of the star to the nearest 1 microsecond (1 degree includes 60 angular minutes, each minute includes 60 angular seconds). To achieve such precision, Ji’s team uses a key technology called laser center-plane measurement.
If approved, the team hopes to be able to build the telescope within five years and put it into orbit 1.5 million kilometers from Earth at the Lagrange 2 point between our planet and the Sun. This is the stable and fuel-efficient observation position used by many spacecraft today, including NASA’s James Webb Space Telescope.
An Khang (Follow SCMP)
at Blogtuan.info – Source: vnexpress.net – Read the original article here
