Are there aliens on other worlds who are more advanced than us? A scientist answers

By Amira Shehata

Sunday, November 19, 2023 at 11:00 p.m

British newspaper “Daily Mail” reports that Professor Jane Greaves of Cardiff University has identified at least two worlds in our Milky Way galaxy, orbiting two stars 70 and 110 light-years away.

“These stars are much older than the Sun (about 8 billion years), which means any planets in them may have had time to radiate less,” he said. “This puts the planets at an age that must be heated and the available radiative heat is balanced as Earth.” When its continents appeared.

Professor Greaves believes that it is worth looking at these rocky worlds as soon as possible, as there is a high probability that life on them could exist on Earth.

The two stars, known as HD 76932 and HD 201891, were born in our galaxy’s ancient and turbulent past, but could have “more advanced biospheres” than our planet, he said.

Continents form due to plate tectonics, which involves the movement of rocky plates floating above the planet’s molten interior.

Over the course of Earth’s 4.5 billion year history, these plates have moved as a result of the heat generated by radiative processes on the planet as landmasses have split, drifted apart, and been pushed back together.

This heat comes from radioactive elements such as uranium-238, thorium-232 and potassium-40 found in the Earth’s core, which release energy as they decay.

Professor Greaves said that if astronomers found evidence of the abundance of thorium and potassium in stars in distant star systems, it would help them focus on exoplanets with masses similar to our Earth but much older.

“The outlook for finding rocky exoplanets with continents seems very promising,” he concluded.

The closest rocky planet ever discovered outside our solar system is HD 219134b, a giant terrestrial planet orbiting a K-type star 21 light-years from Earth. However, there is no indication that it contains continents.