Discoveries of the cosmos and ancient life on earth wowed scientists and the general public in 2020. However, these big claims require more evidence before they can earn a place in science textbooks.
Cloudy with a chance of life
The scorching landscape of hell next door can be a place to look for life. Telescopes trained on clouds of Venus discovered traces of phosphine in quantities that suggest something must be actively producing the gas (SN: 9/14/20). On Earth, phosphine is emitted by certain bacteria or industrial processes, which has led some astrobiologists to speculate that microbes may live in the relatively temperate upper atmosphere of Venus. However, the analyzes of other research teams suggest that the phosphine detection was a misinterpretation – possibly the result of a coincidence in the data processing (SN: 10/28/20).
For the first time, astronomers may have seen a rapid burst of radio waves in the Milky Way. What’s even more fascinating is that the source of the super bright surge in radio waves appears to be a magnetar – a type of neutron star with an intense magnetic field (SN: 06/04/20). However, it is too early to claim that magnetars caused one of the dozen previously discovered high-speed radio bursts, as those flashes came from galaxies too far away to trace the bursts back to a source.
Tubes stuck to the outer shells of hundreds of fossilized brachiopods discovered during an outcrop in China may have housed the earliest known parasites. The shell-like brachiopods lived about 512 million years ago. Researchers speculate that organisms living in the tubes stole food from their filter-fed hosts (SN: 06/02/20). That the tubes were never found alone or on other fossils in the outcrop suggests that the organisms could not survive alone. However, some critics have questioned whether the relationship was really parasitic, as the battered brachiopods were no worse off than their tube-free counterparts.
Found: ordinary matter
Only about half of the expected amount of common matter in the universe has ever been cataloged. But this year astronomers claimed that the other half is hiding in intergalactic space (SN: 05/27/20). This conclusion is based on an analysis of how a small sample of rapid radio bursts from other galaxies was distorted by particles en route to Earth. Before the missing matter case can be closed, however, more of these bright radio wave rays must be examined.
Start your cosmic engines
A ghostly subatomic particle may have been revved up by a star’s destructive encounter with a black hole. The neutrino detected by the IceCube detector in Antarctica carried 200 trillion electron volts – about 30 times as much energy as a proton accelerated by the Large Hadron Collider. Scientists have tuned neutrino detection to a flash of light in the sky caused by a black hole that tears apart a star. The probability that the neutrino and lightning will coincidentally coincide is only 0.2 percent. If the finding is correct, it is only the second time that a high-energy neutrino has been traced back to its source, and the first direct evidence that crushing a star can accelerate neutrinos to high energies (SN: 05/26/20).
The longstanding debate about when people first traveled to and from America continues. A group of researchers reported that people came to North America more than 15,000 years earlier than is generally believed, based on the discovery of stone tools around 33,000 years old found in Mexico (SN: 07/22/20). However, some archaeologists doubt that the artifacts are even stone tools, saying that they are just naturally broken stones instead.
Another research group reported that indigenous South Americans crossed thousands of kilometers of open ocean and reached eastern Polynesia more than 800 years ago, not long after settlers from Asia originally colonized the islands (SN: 07/08/20). This conclusion is based on genetic evidence suggesting that the intrepid South Americans were paired with ancient Polynesians. However, some anthropologists wonder if early South American groups had the equipment or seafaring skills necessary for the trip. The ancient Polynesians, who were seasoned seafarers, may have traveled to South America and brought new DNA with them on their way back home.