Cold alien planet could shed light on Earth's future

By Alimat Aliyeva

Astronomers say that the first rocky planet orbiting an extinct star called a "white dwarf" gives an idea of what the Earth will be like in billions of years. This celestial body shows that, despite its coldness, our planet can become a deserted outpost in space after the Sun fades, Azernews reports.

This planet, whose mass is about 1.9 times the mass of the Earth, is being studied based on data from a telescope located on the Hawaiian Islands. According to the study, the newly discovered planet orbits a "white dwarf" near the bulge of space in the center of the Milky Way galaxy, about 4,200 light-years from the Solar System. A light—year is the distance that light travels in one year, and is approximately 9.5 trillion kilometers.

The "white dwarf" was an ordinary star with a mass one or two times the mass of the Sun. Its current mass is about half the mass of the Sun. Stars eight times less massive than the Sun dim and contract, turning into "white dwarfs", the most common type of remnant stars.

Before the "death" of the parent star, the new planet rotated at a certain distance. It is neither very hot nor too cold, and it is possible that liquid water may exist on its surface and possibly support life. Initially, it rotated at the same distance as the Earth from the Sun. After the extinction of the star, the planet was 2.1 times farther from its place.

Zhang Keming, an astronomer at the University of California and lead author of the study, said this planet is an icy world because the smaller "white dwarf" is extremely faint compared to when it was a normal star.

Astronomers say that the Sun, which is about 4.5 billion years old, will also turn into a "white dwarf". Jessica Lu, an astronomer at the University of California and co-author of the study, says: "At the end of our Sun's life, it will grow to gigantic proportions. Astronomers call it a red giant, the outer layers of which will be gently blown away by the wind. As our Sun loses mass, the orbits of the planets expand to larger sizes. Eventually, the Sun will lose all its outer layers, leaving behind a hot core. He is called a "white dwarf".

Scientists are debating whether the Earth will enter the red giant phase, which is estimated to occur in 7 billion years.