Mysterious Planet-Like Objects in the Orion Nebula Are Baffling Astronomers

The James Webb Space Telescope has observed dozens of Jupiter-mass, often paired objects, nicknamed JuMBOs, raising questions about how they formed

a color image of the Orion Nebula
The James Webb Space Telescope captured this long-wavelength color composite image of the Orion Nebula using its Near Infrared Camera (NIRCam) instrument. NASA, ESA, CSA / Science leads and image processing: M. McCaughrean, S. Pearson, CC BY-SA 3.0 IGO

Thanks to new images of the Orion Nebula from the James Webb Space Telescope, astronomers have discovered dozens of mysterious celestial bodies that defy their understanding of how stars and planets form. Researchers have named them Jupiter Mass Binary Objects—or JuMBOs for short—and they may represent a brand-new astronomical category.

The baffling objects are too small to be stars, and because none orbit a parent star, they can’t be technically classified as planets, either.

“It seems we’re missing something in all of the theories we’ve got so far,” says Matthew Bate, an astrophysicist at the University of Exeter in England who was not involved in the new observations, to the Guardian’s Hannah Devlin. “It seems that there’s a mechanism that’s forming these [objects] that we haven’t thought of yet.”

Scientists shared their findings—which have not been peer-reviewed—online on Monday.

Since it launched in December 2021, the James Webb Space Telescope has confirmed an exoplanet, provided a new view of Uranus’ rings and produced a dazzling portrait of the Pillars of Creation, to name a few achievements. This time around, the powerhouse telescope turned its instruments toward the Orion Nebula, also known as Messier 42, an area of gas and dust located some 1,350 light-years away from Earth.

It’s the closest large star-forming region to our planet, and when looking up at the night sky, it appears to be part of the Orion constellation—more specifically, the nebula is part of the “sword” that hangs from the mythical Greek hunter’s “belt.”

James Webb’s images revealed a cluster of nearly 150 free-floating objects, each with about the same mass as Jupiter, that astronomers can’t quite explain. Existing theories suggest it’s not possible for such small objects to form from the gas and dust within a nebula. Even more perplexing, many of the objects exist in pairs—had the JuMBOs been ejected from young stars’ orbits, that still would not explain how they paired up. The new Webb images show 42 such couplings.

“It’s like kicking a cup of tea across a room and having all the tea land in the teacup,” says Samuel Pearson, an astrophysicist at the European Space Agency who co-authored the JuMBO observations, to the New York Times’ Jonathan O’Callaghan. “And then doing that 42 times.”

Image of gas in space
This section of the James Webb Space Telescope's short-wavelength infrared image of the Orion Nebula shows 'fingers' of gas. NASA, ESA, CSA / Science leads and image processing: M. McCaughrean, S. Pearson, CC BY-SA 3.0 IGO

Researchers decided to take a closer look at the Orion Nebula using the James Webb telescope after ground-based observations suggested something funky might be going on there—more specifically, the team suspected Webb might help them observe “very small objects,” as Mark McCaughrean, a senior adviser for science and exploration at the European Space Agency, tells the Guardian. And while that’s exactly what happened, the new observations bring up more questions than answers.

“We find them down as small as one Jupiter mass, even half a Jupiter mass, floating freely, not attached to a star,” McCaughrean adds to the publication. “Physics says you can’t even make objects that small. We wanted to see, can we break physics? And I think we have, which is good.”

Scientists estimate the JuMBOs are one million years old and have surface temperatures of more than 1,000 degrees Fahrenheit. Since they don’t have a parent star, however, their temperatures will likely drop.

For now, astronomers are still trying to figure out how and why the objects formed, as well as what their existence means for current theories about star and planet formation. They plan to look for JuMBOs in other nebulas and use the telescope’s observations to figure out what they are made of. For now, all they can identify is water and methane.

“Maybe all star formation regions host these double-Jupiters (and maybe even double-Neptunes and double Earths!), and we just haven’t had a telescope powerful enough to see them before,” Heidi Hammel, an astronomer who works on James Webb Space Telescope projects but was not involved in the JuMBO observations, tells BBC News’ Jonathan Amos.

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