2020-11-16

Research believes that the Milky Way may have hundreds of millions of potentially habitable planets

By yqqlm yqqlm

Xinhua News Agency, Beijing, November 15 New Media Special News The US media stated that according to the most conservative interpretation of a new study to be published in the American Astronomy Journal, our galaxy has at least about 300 million potentially habitable planets. Some of these exoplanets may even be our interstellar neighbors, and at least 4 of them may be less than 30 light-years away from the sun. The nearest may be up to 20 light years. These figures are based on the most conservative estimate, that is, 7%of sun-like stars have such a planet. According to the average expected ratio of 50%, there will be more such planets.

According to a report on the US Daily Science website on November 6, this study can help us understand how likely it is that these planets have elements that can support the existence of life. This is an important part of astrobiology, which specializes in the origin of life and the future of the universe.

It is reported that the authors of the paper are all scientists from the National Aeronautics and Space Administration (NASA). Collaborators from all over the place perform Kepler tasks together. In 2018, Kepler ran out of fuel and NASA announced its retirement. Nine years of observations by this space telescope have shown that there are billions of planets in the Milky Way—there are more planets than stars.

Steve Bryson, a researcher at NASA Ames Research Center and the first author of the paper, said:”Kepler The telescope has told us that there are billions of planets, and now we know that a large part of them may be rocky habitable planets. Although this result is far from conclusive, and the presence of water on the planet’s surface just supports the existence of life It’s one of the many factors that we can calculate with such certainty and precision that there are so many planets, which makes people very excited.”

According to reports, in order to calculate the incidence, the research team explored the radius It is an exoplanet that is half to 1.5 times the radius of the Earth, and then the range is reduced to the most likely rocky planet. They also focused on stars that are similar in age and temperature to the sun.

The report pointed out that there are countless such stars, each with its own distinctive characteristics, which affect whether the rocky planet in its orbit can support the existence of liquid water. Partly because of these complex factors, it is difficult to calculate how many potentially habitable planets are in the Milky Way, especially when the most powerful telescopes cannot detect these asteroids. As a result, the research team took a different approach.

Reported that the original intention of the Kepler Telescope was to understand how many potentially habitable planets are in the Milky Way, and the latest research results have taken an important step in this regard. Previous estimates of the frequency of occurrence of such planets ignored the relationship between the temperature of the star and the type of light that the star emits and is absorbed by the planet.

The latest analysis explains this relationship, giving people a more comprehensive understanding of whether a particular planet can support the existence of liquid water and even life. According to this method, the research team combined the planetary signal data set finally obtained by the Kepler telescope with a large amount of data collected by the European Space Agency’s Gaia probe.

One of the authors of the paper and a scientist at NASA Goddard Space Center said:“We have always known that based on the physical distance between the planet and the star, it is neither too hot nor too hot. Not too cold as the standard to define habitability has led us to make a lot of assumptions. The data of’Gaia’ on stars allows us to explore these planets and their stars in a new way.”

Report It is also said that based on the flux of the star, that is, the total amount of energy released by a certain area in a certain period of time,”Gaia” provides information about the amount of energy given to the planet by the host star. In this way, researchers can take into account the diversity of stars in the Milky Way and the solar system when analyzing.

Kupalup said:”Stars are different, and so are planets.”

The report pointed out that although its exact impact is still under study, the atmosphere of the planet is also related to the planet. How much light is needed on the surface to store liquid water. Using conservative estimates of the impact on the atmosphere, researchers speculate that the incidence is about 50%, that is, about half of sun-like stars have rocky planets with liquid water on their surfaces. Another optimistic definition of a livable area estimates this incidence to be approximately 75%.