There could be an invisible planet hiding on the edge of our planet Solar System? Can black holes bounce 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 do it again?
These may not be the questions that first led people to study the stars thousands of years ago. But as astronomers peer ever deeper into the dusty corners of the cosmos, strange discoveries have forced them to grapple with ever stranger questions about the nature of our universe and the limits of what might be out 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 the orbit of Neptune, a mysterious, massive entity may be moving through the ring of icy objects that surrounds our solar system. Scientists studying the area have found that the orbits of more than a dozen rocky objects are subtly altered, as if they were being pulled by the gravity of a huge, 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 takes up to 10,000 years to complete one orbit around the Sun. But apart from strange “knots” in the orbits of nearby objects, there is still no concrete evidence of the existence of planet nine. If it’s out there, slowly orbiting more than 500 times farther from the Sun than Earth, the mysterious world is too faint to be detected with current telescopes.
However, upcoming 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 find further evidence of the elusive world – potentially confirming or disproving its existence once and for all.
“Black Hole on the Run”
In April 2023, astronomers announced the detection of something never seen before: a “runaway” black holeuntethered to any galaxy and blazing through space at 4500 times the speed of sound with a vast trail of stars trailing 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 across (about twice the diameter Milky Way). Observations from the Keck Telescope in Hawaii found that one end of this star trail appeared to be connected to a distant dwarf galaxy from which the freely rotating black hole could be observed astronomically.
Black holes they form the heart of large galaxies like our Milky Way and anchor the surrounding gas, dust and star systems in place. So how can one of these space monsters simply vamoose? According to the study’s authors, it’s possible that the black hole once orbited a second black hole in a rare binary arrangement — and when a third black hole was introduced into the system during a galaxy merger, chaotic gravitational interactions sent one black hole flying. into the wild darkness there. If confirmed by subsequent studiesit will be the first evidence that black holes can escape from their galaxies.
James Webb Telescope’s JUMBO
Black holes are not the only space fugitives; planets were also seen on the lam, and in much greater numbers. In 2023, he discovered the James Webb Space Telescope (JWST). over 500 free-floating “rogue” planets floating through the Orion Nebula. Around 80 of them have been seen orbiting each other in binary pairs – a phenomenon with no clear explanation. Because these rogue worlds are roughly the size of Jupiter, scientists have named them Jupiter-mass binaries—or JUMBOs.
NASA estimates that it may exist trillions of rogue planets the wanderings of our galaxies, many of which were forced out of orbit during the chaotic early days of the star system’s formation. However, current models do not explain the existence of JUMBO. One theory suggests that these bizarre objects formed directly from collapsing clouds of gas and dust in interstellar space, a scaled-down version of how stars form. Another theory says that a passing star could have pushed the objects out of orbit, but the models showed that this explanation is highly unlikely. For the time being, JUMBOs represent a large-scale puzzle for astronomers.
Fermi bubbles
The black hole at the center of our galaxy isn’t (hopefully) going anywhere anytime soon, but in the not-too-distant past it behaved in unexpected ways. Astronomers can see evidence of massive energetic eruptions from our black hole in the form of two sets of giant bubbles – known as Fermi bubbles and eROSITA bubbles — that tower above our galaxy. These overlapping lobes of energy stretch over the center of the Milky Way like a giant hourglass, stretching roughly 25,000 light-years above and below our central black hole. Measured together, the bubbles cover about half the width of the galaxy itself.
Despite their extraordinary size, you can’t see them in the sky; The Fermi bubbles, filled with fast-moving particles called cosmic rays, can only be detected by telescopes that detect gamma rays, while the eROSITA bubbles – filled with extremely hot gas – are only visible as X-rays.
Astronomers don’t know exactly how the bubbles formed, but a 2022 study suggested they were the result of a huge a black hole explosion that lasted more than 100,000 years, beginning about 2.6 million years ago, when a huge amount 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 we thought.
Big question
While studying a peculiar blur of starlight known as Herbig-Haro 46/47, JWST spotted something even more mysterious in the far background of its image – a flood of hot gas in deep space. shaped perfectly like a question mark.
It’s not clear 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, and its light is stretched to redder and redder wavelengths as it traverses vast cosmic distances to reach us. It could be a galaxy, or perhaps several galaxies, tearing each other apart during a chaotic merger, the researchers told sister site Live Science. Space.com in 2023.
Whatever it is, the cosmic question mark is just one of many puzzles raised by JWST’s pioneering observations. Uncovering her identity may have to take a backseat to more pressing questions—like ours completely wrong in our understanding of the universe?