Earth-like life may exist on 'zombie planet'

(NLDO) - The shocking discovery by American scientists about a deadly exoplanet could reveal the future of the solar system 5 billion years from now.

A research team led by astronomer Aomawa Shields from the University of California at Irvine (USA) compared the climates of planets with water and Earth-like atmospheric composition orbiting two types of stars: white dwarfs and main-sequence K-dwarf stars Kepler-62.

Of the two types of stars, white dwarfs are the “zombies.” They are the remnants of Sun-like stars that have run out of energy and died.

Around them there may still be some remaining planets, previously thought to exist in a state of "zombie" death.

Earth-like life may exist on planets orbiting white dwarfs - Illustration AI: Thu Anh

But using a 3D global climate computer model commonly used to study Earth's environment, American researchers discovered a shocking truth: Planets around white dwarfs are even more habitable than planets orbiting Kepler-62.

Although white dwarfs may still radiate some heat from residual nuclear activity in their outer layers, they no longer undergo nuclear fusion in their cores, according to Dr. Shields.

Previously, scientists often did not pay much attention to the possibility of life on planets located in the habitable zones of these "zombie" stars. The habitable zone of white dwarf stars is much closer to the star than that of "living" stars.

So it could be that these worlds are tidally locked to their parent star, meaning they always face the same side toward the star, just as the Moon always faces the same side toward Earth.

In normal stars, this condition could make the dayside of the planet too hot, or conversely too cold due to too many clouds, as is the case with Kepler-62.

In contrast, planets orbiting white dwarfs are closer to their parent stars, and their rotation speeds are so fast that they could never produce as many clouds as the planet around Kepler-62.

Less cloud cover during the day and a stronger greenhouse effect at night create warmer conditions, more similar to the environment on Earth. So not only would this kind of "zombie" world be habitable, its ecosystem would also be very Earth-like.

These results suggest that white dwarf environments – once considered inhospitable to life – could open up new avenues for exoplanet and astrobiology researchers to pursue,” said Dr. Shields.

The discovery also opens a "narrow window" for life in the solar system - including Earth - 5 billion years from now, when our parent star also turns into a white dwarf.

Source: https://nld.com.vn/su-song-giong-trai-dat-co-the-hien-dien-o-hanh-tinh-thay-ma-196250215084026609.htm