Scientists Just Found Thousands of Exoplanets Outside Our Galaxy

Monday, 05 February 2018 - 10:03AM
Monday, 05 February 2018 - 10:03AM
Scientists Just Found Thousands of Exoplanets Outside Our Galaxy
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Image credit: YouTube

Astronomy is advancing in leaps and bounds lately, with a series of incredible new finds that help to inform our growing understanding of the universe.

Now, an important milestone has been made: for the very first time, scientists have been able to positively identify exoplanets that exist beyond the reach of our own Milky Way galaxy.

Up until now, while we've been pretty certain that planets must exist in foreign galaxies, we haven't actually be able to spot them—not because they're hiding, but simply because there's a limit to how far our sensors can reach. Planets are harder to spot than stars because, generally speaking, they don't give off as much energy, and their gravitational fields are far more difficult to pick out among the maelstrom of the universe.

As there are a lot of stars that are closer to the Earth than these distant planets, there's a lot of bright, distracting lights in the sky that keep us from being able to see clearly outside our own galaxy.

In order to get a better look at the blackness surrounding stars in other galaxies, researchers from the University of Oklahoma have made use of a technique called gravitational microlensing to peer further out into space than would otherwise be possible. Large, heavy objects in space distort the travel of light around them, so by focusing closely on the light that surrounds, say, a heavy neutron star, it's possible to catch a glimpse of what lies behind some of the brighter lights in the sky.

Essentially, viewing the stars through microlensing is a lot like using a curved mirror to look around a corner, but in space. The image isn't necessarily perfectly clear, but you can see a lot further using this technique than would otherwise be possible.

As a result of using microlensing to their advantages, scientists Xinyu Dai and Eduardo Guerras have now done what nobody has done before: they've spotted three dim planets orbiting a star that's hiding behind the RXJ 1131–1231 quasar.

According to Guerras:

Opening quote
"This is an example of how powerful the techniques of analysis of extragalactic microlensing can be. This galaxy is located 3.8 billion light-years away, and there is not the slightest chance of observing these planets directly, not even with the best telescope one can imagine in a science fiction scenario. However, we are able to study them, unveil their presence and even have an idea of their masses. This is very cool science."
Closing quote

There's still a lot of research to be undertaken with these planets in order to learn more about them, and there's probably a limit to just how much we'll be able to figure out while squinting through an intergalactic fairground mirror, but regardless, this is a hugely impressive breakthrough in our ongoing quest to learn as much as possible about the universe in which we live.

With any luck, this technique will lead to the discovery of plenty more distant planets in the coming months and years. It's worth assuming that this will lead to yet more incredible discoveries about how stars and planets from across the entire universe, leading us to yet more breakthroughs, and a better knowledge of what literally makes the worlds go round.