2020 will be remembered as a tough year. It’s been a year of incredible tragedies, some beyond our control and others very much the consequences of our actions. We can find some comfort and solace in the fact that even in this dark time, scientists have learned more about our incredible universe.
Betelgeuse's unexplained dimming
Yes, the Betelgeuse dimming happened this year. As the pandemic spread and wildfires raged across Australia and World War 3 almost started, the star dropped out of the top 20 brightest stars in the night sky, reaching its dimmest magnitude since records began.
At its minimum, it was only 37 percent of its usual brightness. In late-February, the star began climbing in luminosity again. The reason for this unexpected drop in brightness is uncertain, but one theory suggests it was caused by a giant star spot. Hopefully, future observations will provide more clarity.
The red supergiant star Betelgeuse as it was dimming. ESO/M. Montargès et al. CC BY 4.0
Grains older than the Sun
Meteorites are fragments of the asteroid that formed at the very beginning of the Solar System almost 5 billion years ago. Most of them have remained unaltered since then – an original piece of the material present when the Sun and planets had just formed.
This year, researchers discovered traces of what was there before, with studies on grains from two meteorites that pre-date the Solar System, one of which could be as old as 7 billion years – the oldest material known.
Water on the Moon
Researchers have finally confirmed the presence of water on the Moon. Although evidence has been mounting for years, scientists were only able to say with certainty there is water present in the lunar soil a few months ago. There is roughly one glass of water per ton of soil.
Researchers also discovered that cold traps – regions in constant shadow – are a lot more common too, so some of that water might be in the form of ice.
Brightest supernova
Back in April, researchers discovered the brightest supernova, twice as bright as any stellar demise seen before. Astronomers believe this happened thanks to an incredible coincidence. First, a star released a large shell of material into space. Then it went supernova, releasing a huge amount of energy and material that slammed into the original shell, creating the observed bump in luminosity.
Three-way black hole interaction released a flare and gravitational waves
Apart from its innuendos, this phenomenal observation was groundbreaking for many reasons. Two black holes collided as they orbited a supermassive black hole. The collision was the heaviest black hole merger ever seen by gravitational wave observatories and it also released a flare, something that has never been seen before in such an event.
The resulting black hole continues to orbit the much larger supermassive black hole and researchers believe it might produce a new flare in the future. This is one to look out for.
Biggest explosion since the Big Bang
This year saw astronomers measure the largest explosion in the history of the universe. A supermassive black hole released such a powerful burst of energy that it created a cavity in the plasma surrounding its host galaxy that could fit 15 Milky Ways (not the chocolate bar) side-by-side. It was five times more powerful than anything we have observed before.
Fast radio burst in the Milky Way
Fast radio bursts (FRB) are mysterious, energetic, and very short emissions of radio waves coming from beyond the Milky Way. There are many uncertainties concerning their sources, but it has been a good year in terms of finding more details about the few FRBs known to be repeating.
2020 also marks the first discovery of an FRB in the Milky Way with a magnetar (an extremely magnetic neutron star) releasing an emission just 30,000 light-years away.
Phosphine was discovered on Venus. Well, maybe
September brought the exciting possibility of phosphine among the clouds of Venus. This gas is only produced by living organisms on Earth and is considered a possible bio-signature when looking elsewhere in the Universe for life, so the detection spurred speculation about its source.
Follow-up analysis revealed the results might not be as strong as previously thought (but hey, that’s science). There was also an issue with the original data. The team claim they are now going over the data again. Hopefully, we’ll know more in the next few months.
Networks of lakes on Mars
Water on Mars is not found on its surface but underground. Researchers had previously announced the discovery of a vast underground lake near the Martian south pole, but now they report that it is not just one lake. There is an entire network of underground lakes on Mars. We have no way of knowing yet if they are habitable, but it is an exciting finding nonetheless.
The year of asteroid samples
2020 saw several important discoveries regarding asteroids and how they evolved. Yet many eyes have been on the samples. NASA’s OSIRIS-REx performed a successful sample collection from asteroid Bennu in October and is getting ready to come back to Earth over the next 2.5 years. Just this month, the Japanese Hayabusa2 dropped its precious cargo of samples from asteroid Ryugu on Earth, the second time a pristine asteroid sample has ever been brought here.
