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NASA Hubble Links 25 Alien Worlds, Introduces New Dawn of Exoplanet Research

A bunch of Jupiter-like giants have strikingly similar atmospheric conditions -- opening the door to an ultimate, unified theory of planet formation.

Monisha Ravisetti Former Science Writer
Monisha Ravisetti was a science writer at CNET. She covered climate change, space rockets, mathematical puzzles, dinosaur bones, black holes, supernovas, and sometimes, the drama of philosophical thought experiments. Previously, she was a science reporter with a startup publication called The Academic Times, and before that, was an immunology researcher at Weill Cornell Medical Center in New York. She graduated from New York University in 2018 with a B.A. in philosophy, physics and chemistry. When she's not at her desk, she's trying (and failing) to raise her online chess rating. Her favorite movies are Dunkirk and Marcel the Shell with Shoes On.
Monisha Ravisetti
3 min read
What the study team's brilliantly colored exoplanets might look like out in the universe.

An artist's concept of the 25 exoplanets examined in the study.

ESA/Hubble, N. Bartmann

After scrutinizing a staggering one thousand hours of telescope data -- divided between observations from NASA's Hubble and Spitzer -- international scientists discovered that a bunch of exoplanets scattered across the universe are inextricably linked by their atmospheres, marking a major milestone for the study of interstellar worlds. 

It's like a cosmic-doppelganger situation, but one that could elucidate how planets we're more familiar with, such as Earth and Mars, formed once upon a time. 

"Our paper marks a turning point for the field: We are now moving from the characterization of individual exoplanet atmospheres to the characterization of atmospheric populations," Billy Edwards, an astronomer at University College London and co-author of a study on the discovery published Monday in The Astrophysical Journal said in a statement.

Think of it like this: Say you want to understand the sounds and syllables of every language, but only have five words to work with. That's pretty difficult. But if you had 10,000 words to work with, you could find similarities between them, group them according to language, and perhaps extrapolate what the rest of the word ledger would sound like. Eventually, you might even find a linguistic rule to help decode the architecture of language altogether.

Likewise, in the past, we only had the planets of our solar system to understand different kinds of planet formation. Over time, we started spotting exoplanets throughout deep space, and today, we have thousands upon thousands of foreign worlds at our disposal -- a whopping sample size poised to grow exponentially thanks to the recent launch of NASA's James Webb Space Telescope

So, with such a rich exoplanet database, the new study's researchers decided to start piecing together which planets might come from the same "language" to understand their classification and maybe even take steps toward uncovering a unified planet formation theory. That'd be like the ultimate "linguistic rule."

"Many issues such as the origins of the water on Earth, the formation of the moon, and the different evolutionary histories of Earth and Mars are still unsolved despite our ability to obtain in-situ measurements," Quentin Changeat, an astronomer at University College London and lead author of the paper, said in a statement. "Large exoplanet population studies, such as the one we present here, aim at understanding those general processes."


An artist's rendition of planet HD 219134b, the nearby rocky exoplanet found outside our solar system. At 1.6 times the size of Earth it orbits its star every three days. 


For the study, the researchers specifically curated their 25 exoplanet subjects because the orbs already had a lot in common. They're super hot gas giants that orbit relatively close to a host star -- akin to our solar system's sunset-colored Jupiter, which hangs out around our sun. 

The team basically wondered whether there were more things they could add to the exoplanet similarity list, especially with regard to atmospheres. Sure enough, the new study determined that some of these exoplanets do indeed share common atmospheric, and even thermal, conditions. Further, they exhibit shared chemical properties and a few other things. 

These similarities, in essence, helped the researchers find trends between the doppelganger exoplanets. More specifically, according to the paper, the correlations helped answer five important, yet outstanding, exoplanet questions. In a sense, these solutions might've brought humanity slightly closer -- very, very slightly -- to a comprehensive understanding of how all the rocky, gassy, icy, weird and familiar worlds that speckle the universe came to be. 

The team notes that further research is required to bolster some of their findings, especially a few correlations regarding thermal similarities. 

Still, the sheer depth of the work is a rather brilliant achievement. It's extremely hard to inspect one exoplanet, let alone the over two dozen studied in the new paper. "Hubble enabled the in-depth characterization of 25 exoplanets," Changeat said, "and the amount of information we learned about their chemistry and formation -- thanks to a decade of intense observing campaigns -- is incredible."