Stephen Kane is searching for stars that might harbor planets with mild, warm climates that favor life — you know, like Earth — when he caught a glimpse of a young red dwarf star called AU Microscopii.” only 32 light years from home.”
“The star is a complete child, when it comes to planetary systems. That means we have the opportunity here to observe a planet at the earliest stage of planetary evolution,” he said. So Kane, an astrophysicist at the University of California at Riverside, and his colleagues have used the star as a laboratory and model for others like it, predicting the future. live in its future. That helped them figure out when planets orbiting it might fall.”residential area“—A distance that is neither too hot nor too cold to support life. They found that the star would glow brightly at first, then soften and burn less intensely, so that the range of life-friendly spots would move about 30 to 40 percent closer to the star in the future. The first 200 million years of the star. They published their work this month in Astronomy Magazine.
That makes sense for Kane and other scientists, who hope to one day see a life-friendly world beyond Earth, with a verdant ecosystem full of life forms. aliens, because it suggests that a planet in a habitable place may not last forever. For the “Goldilocks” best-case scenario, everything has to be just right, including the temperature that allows the planet to have liquid water on its surface – a prerequisite for life as we know it. (Life like us do not know it is another story.) Other factors are also important, like a breathable atmosphere, a stable climate, and enough protection from extreme ultraviolet radiation. Mars, for example, is in our sun habitable region, but it lost water and most of its atmosphere months ago. Venus lies at the inner edge of the region, but thanks to a carbon dioxide film, it heats up.
AU Microscopii offers scientists a glimpse of how that region can grow or shrink over a star’s lifetime. “These red dwarfs have a very long, very bad adolescence. It could be hundreds of millions of years before a star like this finally settles down as an adult,” said Sara Seager, MIT astrophysicist and former deputy chief science officer of NASA’s planet-finding mission. , said TESS.
Kane and his team show that just as their red dwarf and other stars like it can act like teenagers for a while, a currently nasty world could become livable. than. But the opposite is also possible: “A planet that is in the habitable zone now may not be there as the star is changing,” he said.
If the host star cools slightly, the planet could become too cold for any ET people to make a living on it; Lakes and rivers will gradually freeze. On the other hand, much older stars usually end up heating up, so aliens who were once in a life-friendly place could end up seeing the water needed for life to boil, for whatever Anything on their planet’s surface is toasted to death.
