Medical discoveries dominated the news in 2020, but even under pandemic circumstances, astronomers continued their work. They searched for mystery signals via radio waves, discovered new galaxies, and even discovered which alien galaxies could detect Earth.
Radio emissions from an alien world
Planets in the solar system emit radio waves, especially Jupiter with its intense magnetic fields. But no one had ever detected radio waves emanating from a planet outside the Solar System until this year, when researchers picked up a signal from a gas giant in the Tau Boötes System, just 51 light-years from Earth. That signal could help them learn more about that exoplanet’s magnetic field, which could provide clues as to what is happening in its atmosphere.
X-ray blobs bursting from the Milky Way
Millions of years ago, an explosion in the center of the Milky Way blew energetic material above and below the galactic disk. That material is still visible and glows in the gamma-ray spectrum in two clumps discovered in 2010, known as the Fermi Bubbles. In 2020, researchers found a few more blobs in the same region, visible in the X-ray spectrum. Probably related to the Fermi bubbles, these faint, gigantic features of the Milky Way tower above the 25,000 light-year Fermi bubbles, reaching a width of 45,000 light-years from end to end. Researchers called them the “eROSITA bubbles”.
A long-lost missile booster
In 2020, Earth acquired a new “minimoon”, one of many objects the planet encounters in space from time to time that will orbit our planet. But closer examination by amateur and professional astronauts revealed that this minimoon was not a natural object at all, but rather a rocket booster launched by NASA in the 1960s.
Ghostly radio circles
Scientists often find things in space that look like fuzzy blobs, but the newly discovered odd radio circles (ORCs) discovered in 2019 and reported in 2020 are special. The round blobs, visible in radio telescope data, do not look like a known object. They are not supernova remnants or optical effects known as Einstein rings. Some scientists have even suggested they might be wormholes’ throats. But no one really knows what these newly discovered things are.
A million new galaxies
A radio telescope in the Australian outback mapped 83% of the observable universe over 300 hours of observations. And it revealed a large amount of data: 3 million galaxies, a million of which had never been seen before. The Australian Square Kilometer Array Pathfinder (ASKAP) relies on 36 antennas to capture the sky, but this was the first time all 36 had been used at the same time for a single project.
A touch of life on Venus?
Venus is perhaps the most inhospitable place in the solar system, with swirling acidic clouds and hellish temperatures. That’s why astronomers were getting ready to look for phosphine, a smelly gas thought to be a possible signature of life on alien planets, trained their phosphine-hunting telescope on Venus first: they wanted a reference image of a certain dead world . But with a shocking turn, they found the connection in the clouds of Venus.
However, other researchers have urged caution before suggesting that there is real life on Venus.
A newborn magnetar
On Nov. 12, researchers discovered a bright kilonova, a light show from the aftermath of two neutron stars merging. Kilonovas are rare in space, but researchers have seen them before. This one was special, however: strange signals in the kilonova light indicated the presence of something new. Researchers studying the event offered a few possibilities, but said the most likely is a newborn magnetar – a huge, super-magnetic neutron star that formed during the collision.
The source of a fast radio burst
Magnetars can also be responsible for the brightest flashes of light in space. These “fast radio bursts” have baffled astronomers for years, packing the energy the sun emits in days into mere milliseconds. Most seem to come from far beyond the Milky Way, but in 2020 researchers reported that an FRB came from our own galaxy, just 30,000 light-years from Earth. And this one had a known point of origin: a magnetar. Does this mean that all such eruptions are from magnetars? Nobody knows for sure.
The aliens that might see us
Astronomers detect alien planets by watching them pass between Earth and their stars. One day they may even study their atmosphere by watching the starlight shimmer through them. But that only works for planets with orbits aligned to place them between Earth and their home star. Planets that are not so aligned are usually invisible to current telescope technology.
In 2020, researchers asked which galaxies have Earth’s vantage points that allow them to see our tiny planet with its atmosphere pulsating with signs of life. They identified 1,004 galaxies that could see Earth within 326 light-years. One star just 12 light years from Earth has known exoplanets and will have the correct vantage point to see Earth when it gets into position in 2044.
Originally published on Live Science.