The discoveries about the cosmos and ancient life on Earth tempted scientists and the public in 2020. But these big claims require more evidence before they can earn a place in science textbooks.
Cloudy with life chances
The scorching landscape of hell next door can be a place to seek life. Telescopes trained in Venus clouds have detected remnants of phosphine in amounts that suggest something must be actively producing the gas (SN: 14/09/20). On Earth, phosphine is emitted by certain bacteria or industrial processes, leading some astrobiologists to speculate that microbes may be living in the relatively temperate upper atmosphere of Venus. But analyzes by other research teams suggest that phosphine detection was a misreading, perhaps the result of an error in data processing (SN: 28/10/20).
For the first time, astronomers may have glimpsed a rapid explosion of radio in the Milky Way. Even more intriguing, the source of the super bright impulse of radio waves appears to be a magnet: a type of neutron star with an intense magnetic field (SN: 6/4/20). But it’s too early to say that the magnets caused any of the dozens of fast bursts previously detected, as those flashes came from galaxies too far away to track the bursts to a source.
L. ROAD / ESO
Tubes attached to the outer shells of hundreds of fossilized brachiopods discovered in an outcrop in China may have housed the oldest known parasites. Clam-shaped brachiopods lived about 512 million years ago. The researchers speculate that the organisms living inside the tubes passed the food from their hosts who fed the filter (SN: 02/02/20). That the tubes were never found alone or in other fossils in the outcrop suggests that the organisms could not survive on their own. But some critics question whether the relationship was really parasitic, given that the tubed brachiopods did not look worse than their tubeless counterparts.
Zhifei Zhang / Univ. From the Northwest
Found: ordinary matter
About half the amount of ordinary matter expected by the universe has never been cataloged. But this year, astronomers have claimed that the other half is hiding in intergalactic space (SN: 27/05/20). That conclusion is based on an analysis of how a small sample of rapid radio bursts from other galaxies was distorted by particles on their way to Earth. Before the case of the missing matter can be closed, more of these radio wave explosions must be examined.
CSIRO, Alex Cherney
Start your cosmic engines
A spooky subatomic particle may have been developed by the destructive encounter of a star with a black hole. Detected by the IceCube detector in Antarctica, the neutrino carried 200 trillion volts of electrons, about 30 times more energy than that of a proton accelerated by the Large Hadron Collider. Scientists combined neutrino detection with a flash of light in the sky caused by a black hole shattering a star. The probability that the neutrino and the flash coincide by chance is only 0.2 percent. If the finding is maintained, it would be the second time a high-energy neutrino has been traced to its origin, and the first direct evidence that shattering a star can accelerate neutrinos to high energies (SN: 26/05/20).
M. Weiss, CXC / NASA
On the move
The long-standing debate about when humans first traveled to and from the Americas is burning. A group of researchers reported that people arrived in North America more than 15,000 years earlier than previously thought, based on the discovery of approximately 33,000-year-old stone tools unearthed in Mexico (SN: 22/07/20). However, some archaeologists doubt that the artifacts are even stone tools and say that instead they are just naturally broken rocks.
Another research group reported that indigenous South Americans crossed thousands of miles of open ocean and reached eastern Polynesia more than 800 years ago, not long after Asian settlers initially colonized the islands (SN: 8/7/20). That conclusion is based on genetic evidence that suggests intrepid South Americans paired with ancient Polynesians. But some anthropologists question whether early South American groups had the equipment or seafaring skills needed for the voyage. The ancient Polynesians, who were experts in navigators, may have traveled to South America, bringing with them new DNA on a journey back home.