Could an invisible planet be hiding at the confines of our solar system? Can black holes ricochet through space like intergalactic billiard balls? Did our own galaxy’s black hole ‘wake up’ with a bang millions of years ago – and could it happen again?
These may not be the questions that led humans to study the stars thousands of years ago. But as astronomers peer ever deeper into the dusty recesses of the cosmos, peculiar discoveries force them to confront ever stranger questions about the nature of our universe and the limits of what might lie there.
From our own cosmic backyard to the distant depths of the early universe, here are five of the most mysterious objects scientists have discovered in space – and the best explanations for what they are.
Planet nine
Far beyond Neptune’s orbit, a mysterious and massive entity could be moving through the ring of icy objects that surrounds our solar system. Scientists studying this region have discovered that the orbits of more than a dozen rocky objects are subtly altered, as if pulled by the gravity of an enormous, invisible planet – a theoretical object known as Planet Nine.
This hidden world is estimated to be five to ten times more massive than Earth and will take up to 10,000 years to complete a single orbit around the Sun. But aside from strange “folds” in the orbits of nearby objects, there is still no concrete evidence for the existence of Planet Nine. If it’s out there, in slow orbit more than 500 times farther from the sun than Earth, the mysterious world is far too dark to be detected with current telescopes.
However, the next Vera C. Rubin Observatorywhich is currently under construction in Chile and will eventually record a 10-year time-lapse video of the night sky, should be able to spot more evidence of this elusive world – potentially confirming or denying its existence once and for all.
The “runaway black hole”
In April 2023, astronomers reported the detection of something never seen before: a black hole “on the run”independent of any galaxy and traveling through space at 4,500 times the speed of sound, with a huge trail of stars behind it.
The black hole is estimated to be 20 million times the mass of Earth’s sun, while its bright tail could be more than 200,000 light years long (about twice the diameter of the black hole). Milky Way). Observations from the Keck telescope in Hawaii revealed that one end of this stellar trail appears to be linked to a distant dwarf galaxy, from which the freewheeling black hole may have been astronomically distant.
Black holes form the core of large galaxies like our Milky Way, anchoring surrounding systems of gas, dust and stars in place. So how can one of these cosmic behemoths just wander around? According to the study authors, it is possible that the black hole already orbited a second black hole in a rare binary arrangement. Then, when a third black hole was introduced into the system during a galaxy merger, chaotic gravitational interactions sent a black hole flying. in the wild black yonder. If confirmed by follow-up studiesthis will be the first evidence that black holes can escape from their galaxies.
The JUMBOs of the James Webb telescope
Black holes are not the only cosmic fugitives; planets have also been spotted fleeing, and in much greater numbers. In 2023, the James Webb Space Telescope (JWST) detected over 500 floating “rogue” planets careening through the Orion Nebula. Around 80 of them were spotted orbiting each other in binary pairs – a phenomenon with no clear explanation. Because these rogue worlds are about as large as Jupiter, scientists have named them Jupiter Mass Binary Objects – or JUMBOs.
NASA estimates that there could be billions of rogue planets wandering our galaxy, many of which were knocked out of orbit during the chaotic early days of the star system’s formation. However, current models fail to explain the existence of JUMBOs. One theory suggests that these bizarre objects formed directly from the collapse of clouds of gas and dust in interstellar space, in a scaled-down version of how stars form. Another theory says that a passing star could have pushed the objects out of their orbit, but models have shown that this explanation is highly improbable. For now, JUMBOs pose a giant puzzle for astronomers.
Fermi bubbles
The black hole at the center of our galaxy is (hopefully) not going anywhere anytime soon, but it has been acting up unexpectedly in the not-so-distant past. Astronomers can see evidence of massive, energetic eruptions from our black hole in the form of two sets of gargantuan bubbles – known as Fermi bubbles And eROSITA bubbles – this tower above our galaxy. These overlapping energy lobes straddle the center of the Milky Way like a huge hourglass, extending about 25,000 light years above and below our central black hole. Measured together, the bubbles span about half the width of the galaxy itself.
Despite their extraordinary size, we cannot see them in the sky; Fermi bubbles, filled with fast-moving particles called cosmic rays, can only be spotted by telescopes detecting gamma rays, while eROSITA bubbles, filled with extremely hot gases, are only visible as rays x.
Astronomers aren’t sure how the bubbles formed, but a 2022 study suggests they are the result of a gargantuan phenomenon. explosion of a black hole that lasted more than 100,000 years, which began about 2.6 million years ago, when large quantities of matter poured into the maw of our black hole. If confirmed, this hypothesis would suggest that our black hole has been active much more recently than previously thought.
The big question
While studying a strange patch of starlight known as Herbig-Haro 46/47, JWST spotted something even more mysterious in the distant background of its image: a cloud of hot gas in space deep. shaped perfectly like a question mark.
It is not known exactly what the object is or how far away it is, but its reddish color in the JWST images suggests that the object is exceptionally old, with its light extending into wavelengths of more and more red as it crosses vast cosmic distances to reach us. It may be one galaxy, or perhaps several galaxies tearing apart in a chaotic merger, researchers told Live Science’s sister site. Espace.com in 2023.
Regardless, the cosmic question mark is just one of many puzzles introduced by JWST’s groundbreaking observations. Discovering one’s identity may have to take a back seat to more pressing questions – like, are we completely wrong about our understanding of the universe?