Space is no secret to be incredibly strange, but every year astronomers seem to outdo themselves in discovering bizarre new objects and events. From extreme exoplanets to stars with strange fates, clues to an old mystery and the beginnings of a brand new one, here are 10 of the strangest astronomical discoveries that blew us (and scientists) away this year.
Extremely uninhabitable exoplanet
A rocky Super-Earth exoplanet, K2-141b has a very familiar cycle. Like our home planet, it has liquid oceans that evaporate into clouds, then condense and fall back to the surface as rain. But we’re not talking about water here – all of that happens with rock.
Much of K2-141b’s surface is probably covered with a sea of lava. Its incredibly close star would make the weather hot enough to vaporize the rock, creating an atmosphere of silica that would be carried by supersonic winds to the night side of the planet, where it would cool and fall as rocky rain.
So, don’t take offense if we put this planet last on our list of must-visit planets when humans invent warp speed.
The Planet That Never Was
‘ Fomalhaut b was one of the first exoplanets discovered – and this year astronomers rediscovered it. A team that analyzed a decade of Hubble observations found that what was a bright point of light in 2004 had completely disappeared by 2014.
This is obviously not something planets can do easily, and the researchers proposed a pretty neat explanation – Fomalhaut b had never existed. Well, not as a planet, anyway. Computer simulations suggested that it was more likely a dense dust cloud formed by the collision of two asteroids or comets and then drifting apart over a decade.
It is not a planet, but the observation of such a short-lived cosmic event is all the more impressive.
A star is unborn
Planets aren’t the only things that disappear without a trace – a giant, bright star also recently passed quietly into the night.
The object, formerly known as a luminous blue variable star, was located in the dwarf galaxy Kinman at a distance of about 75 million light-years. At that distance, it made its presence known with an incredible light signature that was about 2.5 million times brighter than that of the Sun. Until it didn’t.
The star was last sighted in 2011, but when astronomers went to study it less than a decade later, it had simply disappeared. Normally, you would expect a star like this to go out with a bang and a very obvious supernova, but this one seems to have disappeared in a way that baffles astronomers.
On the subject of stars with strange fates, earlier this year a white dwarf was found to have gone supernova – and survived, against everything we thought we knew.
The clues paint an odd picture. The star has an unusual composition, without the expected hydrogen or helium but packing carbon, sodium and aluminum, which normally aren’t present in white dwarfs. It’s tiny, only about 40 percent the mass of the Sun. And it’s absolutely hooning through the galaxy at a blistering 900,000 km/h (560,000 mph).
The only explanation the team could come up with was that it had somehow gone through a partial supernova and survived. That would have burned off the missing elements, produced the unexpected ones, shrunk its mass, and sent the star hurtling off at its incredible speed.
Black hole turning a star into a planet
Fast radio bursts (FRBs) are one of the most fascinating cosmic mysteries in decades – and this year, new clues to their identity came to light.
Most of these signals are one-off events lasting mere milliseconds, but a few of them have been seen to repeat at random intervals. Or at least, astronomers thought they were random. Early in 2020 astronomers discovered one FRB that repeats on a 16-day cycle, firing off bursts for around four days then falling silent for 12 days.
A few months later, another study discovered a hidden pattern in a famous repeater that’s been watched intently since 2012. Previously thought to be random, eight years of observations revealed that this FRB was on a 157-day cycle, active for 90 days then quiet for 67 days. The team predicted its next active phase for August – and lo and behold, the thing flared back up again on schedule.
But the biggest clue to the FRB mystery, which may unravel their identity, was the first ever detection of one of these signals from our very own galaxy.
On April 28, astronomers picked up activity from a magnetar, an extremely dense neutron star with a powerful magnetic field. Along with the usual X-rays, this one emitted a bright burst of radio waves that looked suspiciously like an FRB. Magnetars were already high on the list of suspects, and this new detection strengthens the case.
Whether they account for any, some, or all FRBs remains to be seen, and will need more observations, but it’s a fascinating lead.
Most magnetic object ever
Another type of neutron star also captured astronomers’ attention this year, with a pulsar found to have the strongest magnetic field we’ve ever observed in the universe.
The team calculated that the magnetic field of this pulsar was as high as one billion Tesla (T). For reference, the Sun’s magnetic field tops out at about 0.4 T, while Earth sports a tiny 30 micro-Tesla. Your average white dwarf star may get as high as 100 T, and the strongest ever created in a lab on Earth is 1,200 T.
Don’t get too close though – this pulsar’s 1 billion T magnetic field would be enough to rip you apart atom by atom.
Brand new cosmic mystery
With the FRB case (almost) closed, we needed a new cosmic mystery to chew on – and space delivered one immediately. “Odd radio circles” (ORCs) are unexplained blobs of radio emission that don’t correspond to any known object or phenomenon.
Only a handful of ORCs have been found so far in radio images, and they don’t give off any optical, infrared or X-ray signals. Astronomers can’t yet tell how far away or big they are, either – they might be spots a few light-years wide lurking within the Milky Way, or they could be way beyond our galaxy and measure millions of light-years wide.
These odd radio circles appear to be a brand new astronomical object, although they may be connected to something we already know about. Either way, watching the observations and clues pour in over the next few years will be exciting.