Earth Isn’t Unique and the Universe is Home to Many Similar Planets Claims New Study

A new method used to study an exoplanet's geochemistry suggests Earth is not unique, and the universe is most likely "full of" rocky Earth-like planets. 

Thought that our planet was unique? Well, think again.

A very large number of similar planets could be scattered all across the universe, which increases probabilities that there are worlds that are as alive as ours is.

That is the conclusion reached by a new study by researchers from the University of California (USA), published this week in the journal Science, and funded by NASA.

“We have just raised the probability that many rocky planets are like the Earth, and there’s a very large number of rocky planets in the universe,” revealed co-author Edward Young, UCLA professor of geochemistry and cosmochemistry.

During the study, the group of scientists analyzed the elements in rocks from asteroids or rocky planet fragments that orbited six white dwarf stars. White dwarf stars are dense, burned-out remnants of traditional stars

In their final evolutionary stage, white dwarfs attract rocky material from smaller objects that orbit around them because they contract and expand.

By analyzing the chemistry of the stars, the scientists managed to understand the composition of the rocks of planets that once orbited it. These data can provide information about its habitability, magnetic field, atmosphere and many other usefully insights.

Artist's impression of the exoplanet Proxima Centauri b shown as of a arid (but not completely water-free) rocky Super-Earth. This appearance is one of several possible outcomes of current theories regarding the development of this exoplanet, while the actual look and structure of the planet is known in no ways at this time. Proxima Centauri b is the closest exoplanet to the Sun and also the closest potentially habitable exoplanet as well. Image Credit: Wikimedia Commons.
Artist’s impression of the exoplanet Proxima Centauri b. Image Credit: Wikimedia Commons.

“We’re studying geochemistry in rocks from other stars, which is almost unheard of,” Young said.

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“Learning the composition of planets outside our solar system is very difficult,” explained co-author Hilke Schlichting.

“We used the only method possible — a method we pioneered — to determine the geochemistry of rocks outside of the solar system.”

By studying the white dwarfs and the elements that exist in their atmosphere, scientists are essentially taking a peek into the elements that were in the core of the body that orbited the white dwarf. The closest white dwarf star studied in the new study is located around 200 light-years from Earth and the farthest is 665 light-years away, according to a statement.

“Observing a white dwarf is like doing an autopsy on the contents of what it has gobbled in its solar system,” Doyle revealed.

The data revealed in the news study and analyzed by scientists was collected by telescopes, most of which came from the W.M. Keck Observatory in Hawaii.

“If I were to just look at a white dwarf star, I would expect to see hydrogen and helium,” Doyle explained.

“But in these data, I also see other materials, such as silicon, magnesium, carbon, and oxygen — material that accreted onto the white dwarfs from bodies that were orbiting them.”

Until now, scientists did not know in detail if the chemistry of rocky exoplanets was similar or substantially different from that of Earth.

Doyle revealed that the rocks analyzed by the UCLA team is very similar to froms from Earth and Mars. “They are Earth-like and Mars-like in terms of their oxidized iron. We’re finding that rocks are rocks everywhere, with very similar geophysics and geochemistry.”

“It’s always been a mystery why the rocks in our solar system are so oxidized,” Young explained.

“It’s not what you expect. A question was whether this would also be true around other stars. Our study says yes. That bodes really well for looking for Earth-like planets in the universe.”