The 12 Strangest Objects in the Universe
A Moon with a Moon
What’s better than a moon? A moon orbiting a moon, which the internet has dubbed a moonmoon. Also known as submoons, moonitos, grandmoons, moonettes and moooons, moonmoons are still only theoretical, but recent calculations suggest that there’s nothing impossible about their formation. Perhaps astronomers may one day discover one.
Dark matter — the unknown substance comprising 85 percent of all matter in the universe — is strange. But researchers are at least sure about one thing: Dark matter is everywhere. So team members were scratching their heads over a peculiar galaxy they spotted in March 2018 that seemed to contain hardly any dark matter. Subsequent work suggested that the celestial oddity did in fact contain dark matter, though the finding paradoxically lent credence to an alternative theory positing that dark matter doesn’t exist at all. Get it together, astronomers!
The Most Bizarre Star
When astronomer Tabetha Boyajian of Louisiana State University and her colleagues first saw the star known as KIC 846285, they were flummoxed. Nicknamed Tabby’s star, the object would dip in brightness at irregular intervals and for odd lengths of time, sometimes by as much as 22 percent. Different theories were invoked, including the possibility of an alien megastructure, but nowadays, most researchers believe the star to be surrounded by an abnormal ring of dust that’s causing the darkening.
Highly Electric Hyperion
The title of weirdest moon in the solar system could go to many celestial objects — Jupiter’s overly volcanic Io, Neptune’s geyser-spewing Triton. But one of the strangest looking is Saturn’s Hyperion, a pumice-stone-like irregular rock pockmarked with numerous craters. NASA’s Cassini spacecraft, which visited the Saturn system between 2004 and 2017, also found that Hyperion was charged with a “particle beam” of static electricity flowing out into space.
A Guiding Neutrino
The single, high-energy neutrino that struck Earth on Sept. 22, 2017, wasn’t, on its own, all that extraordinary. Physicists at the IceCube Neutrino Observatory in Antarctica see neutrinos of similar energy levels at least once a month. But this one was special because it was the first to arrive with enough information about its origin for astronomers to point telescopes in the direction it came from. They figured out that it had been flung at Earth 4 billion years ago by a flaring blazar, a supermassive black hole at the center of a galaxy that had been consuming surrounding material.
The Living Fossil Galaxy
DGSAT I is an ultradiffuse galaxy (UDG), meaning it is as big as a galaxy like the Milky Way but its stars are spread out so thinly that it is nearly invisible. But when scientists saw the ghostly DGSAT 1 in 2016, they noticed that it was sitting all alone, quite unlike other UDGs, which are typically found in clusters. Its characteristics suggest that the faint object formed during a very different era in the universe, back just 1 billion or so years after the Big Bang, making DGSAT 1 a living fossil.
Double Quasar Image
Massive objects curve light, enough so that they can distort the image of things behind them. When researchers used the Hubble Space Telescope to spot a quasar from the early universe, they used it to estimate the universe’s expansion rate and found that it is expanding faster today than it was back then — a finding that disagrees with other measurements. Now physicists need to figure out if their theories are wrong or if something else strange is going on.
Infrared Stream from Space
Neutron stars are extremely dense objects formed after the death of a regular star. Normally, they emit radio waves or higher-energy radiation such as X-rays, but in September 2018, astronomers found a long stream of infrared light coming from a neutron star 800 light-years away from Earth — something never before observed. The researchers proposed that a disk of dust surrounding the neutron star could be generating the signal, but the ultimate explanation has yet to be found.
Rogue Planet with Auroras
Drifting through the galaxy are rogue planets, which have been flung away from their parent star by gravitational forces. One particular peculiarity in this class is known as SIMP J01365663+0933473, a planet-size object 200 light-years away whose magnetic field is more than 200 times stronger than Jupiter’s. This is strong enough to generate flashing auroras in its atmosphere, which can be seen with radio telescopes.