Scientists Discover The First Planets Outside The Milky Way


The truth is out there. And beyond is a group of planets 3.8 billion light-years away, a recent discovery that, if confirmed, could extend the limit of what we know about the universe.

Using data from a NASA X-ray laboratory in space, Xinyu Dai, an astrophysicist and professor at the University of Oklahoma, detected, for the first time in history, a population of planets beyond the Milky Way. The mass of the planets varies in size from the Earth’s moon to the enormous Jupiter, the largest planet in our solar system.

There are few methods to determine the existence of distant planets. They are so far away that no telescope can observe them, Dai told the Washington Post. So Dai and his postdoctoral researcher Eduardo Guerras relied on a scientific principle to make the discovery: Albert Einstein’s theory of relativity.lens galaxy wp

The galaxy lens, in the center, and four background quasars with lenses.

Einstein’s theory suggests that light bends when pulled by the force of gravity. In this case, the light comes from a quasar, the nucleus of a galaxy with a spiraling black hole, which emits powerful radiations in the distance.

Between that quasar and the space laboratory is the galaxy of newly discovered planets. The gravitational force of the galaxy doubles the light that is directed towards the Milky Way, illuminating the galaxy in an effect called microlente. In that way, the galaxy acts like a kind of magnifying glass, carrying a celestial body that had never been seen by X-rays.

The technique was used for the first time to identify planets outside our solar system but within the galaxy, known as exoplanets.

“Microlentence is probably the only way,” said Dai.

In a university press release, Guerras had a less formal way of describing the complicated process: “This is a great science.”

The photo that emerged is a modest image of the extraordinary find that Dai said will advance the study of planetary science. The central elliptical object is the galaxy where the planets reside. The white points linked at the top and the white mark at the bottom are the lens images of the active radiation that pulsates from a black hole.

Dai estimated that distant galaxies contain 2,000 planets for each star. That means that billions of planets probably reside there, he said, consistent with the proportion found in free floating planets in the Milky Way that contains billions of planets.

“This discovery, if the interpretation of the data is maintained, looks very exciting,” Dr. Priyamvada Natarajan, a theoretical astrophysicist at Yale University, told NBC.

But other experts highlighted the skepticism. David Bennett, a NASA gravitational lens expert, said the research was “interesting,” but the data could be interpreted to suggest that the objects were not extragalactic, NBC reported.

The microlens can reveal amazing things, like the same star exploding four times, but the objects in space are not static, and will not always have the perfect quasar backdrop to bathe a given object with arc light. That gives a limited time to make a discovery with almost unlimited galaxies in the sky.

That could make this discovery even more remarkable: the fact that it might not have happened at all. Dai was simply looking to study the environment in and around a black hole. You may have found something else.

“It was coincidence,” he said.