Wu Jialiang (Lecturer of General Education Foundation Course at the Chinese University of Hong Kong) Photo: Radio Television Hong Kong I don't know if you like watching doomsday movies? A very common episode is: an asteroid is about to hit the earth, and human beings try their best to reverse this tragedy, such as launching a nuclear bomb to rewrite the orbit of the asteroid, and finally all human beings are safe and sound. These apocalyptic movies often raise the question: Can we find another planet to live in when the Earth is at stake? When this question is put into the study of astronomers, it becomes: Are there habitable planets outside the solar system that allow liquid water to exist?
Will there be life on these remove background from image planets? Even more intelligent than us? This episode of "Zero Distance Science" is about to explore the possibility of "Second Earth" with you. The vast starry sky search In the past, astronomers often thought that the second Earth only existed in another solar system, ignoring the possibility of red dwarf (Red dwarf) planets also serving as the second Earth. In the vast sky, the proportion of red dwarf stars is much larger than that of stars like the sun. This knowledge suddenly enlightened astronomers! Red dwarfs have lower surface temperatures and brightness than the sun, but they live longer than the sun.
To discover the planets of red dwarf stars, we must rely on the transit method introduced earlier in " Another Solar System " . Because this involves observing small changes in the red dwarf's brightness, space telescopes are more useful than surface-based telescopes because they are not affected by the clouds in Earth's atmosphere. Exoplanet_1 The surface temperature and brightness of the red dwarf star (right) is lower than that of the sun (left). After many efforts by astronomers, and with funding from private institutions and NASA, the space telescope dedicated to searching for the second Earth, the Transiting Exoplanet Survey Satellite (TESS), finally It was launched by SpaceX on April 18, 2018.