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According to the Daily Mail on August 17, a new study shows that one third of the exoplanets that are larger than the earth have water.
Scientists say that every outsole planet that is 2-4 times the size of the earth can have water, the main component of life, indicating that they can have extraterrestrial life. Analysis of data from the Kepler Space Telescope and the Gaia satellite suggest that running or frozen water may form half of the mass of these exoplanets. In contrast, water is only 0.02% of the mass of the earth.
The 4,000 exoplanets that have been identified or are currently identified are classified by size into two categories. The average radius of one type is about 1.5 times as large as that of the earth, while the other type is about 2.5 times.
Dr. Zeng Li, one of the most important researchers at Harvard University in the United States, said: "It is a huge surprise to know that there are so many exoplanets with water, we have studied the relationship between mass and radius and developed a statement for this. The model of the relationship. "This model is based on the mass and radius data of the exoplanets that they recently obtained from the Gaia satellite. The beauty is that it explains how these existing data are related to the composition of the planet.
This model shows that smaller planets are often rocky planets – they are usually five times the mass of the earth. Larger planets are typically ten times the mass of the earth. "It can be a water planet," Dr. said. Zeng. They presented their findings at the Goldschmidt International Conference in Boston and explained: "This is indeed water, but not like the water that occurs on earth." He said that the surface temperatures of these planets are expected to be between 200 and 500 degrees Celsius. Their surface may be covered with an atmosphere with a main component of water vapor and a liquid water layer below it, which goes deeper into the surface and turns the water into ice under high pressure.
The discovery of exoplanets orbiting other stars in 1992 stimulated interest in understanding these planetary groups to determine whether they are suitable for the evolution of life.
Dr. Zeng said: "Our data show that about 35% of all known exoplanets above the earth should be watery, they can be formed in the same way as the giant planets we found in the solar system." Jupiter, Saturn, Uranus and Neptune are similar With ground-based spectroscopic tracking, the newly launched TESS will reveal more of these planets. The new generation of space telescopes – – The James Webb Space Telescope – is expected to reproduce the atmosphere of some exoplanets. This is an exciting time for those who are interested in these distant worlds. "
Professor Sara Seager, a planetary science scientist at the Massachusetts Institute of Technology, who is the deputy science director of the mission, said the mysterious medium-sized exoplanet can be rich in water. I hope that future atmospheric observations can support or deny this new discovery. "
[责编：张梦凡]
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