Science

A 33-year-old man was infected with the coronavirus more than four months after his first attack, the first documented case of so-called reinfection, researchers in Hong Kong reported Monday. The finding was not unexpected, especially considering the millions of people worldwide are infected, experts said. And the man had no …

A team at Jodrell Bank splashed a pattern in the bursts (Getty) Astronomers have welcomed a mysterious radio eruption from space, which repeats in a regular pattern lasting more than 100 days. Researchers at Jodrell Bank Observatory in Macclesfield saw the radio burst (FRB 121102), repeated in a 90-day pattern, …

A global extinction event about 359 million years ago could have been delayed by killing a distant star, a new study suggests. Towards the end of the Devonian period (416 million to 358 million years ago) there was a mass extinction known as the Hangenberg Event; the extinct fish called …

An artistic illustration of what Planet 9 would look like, if it existed. Credit: R. Hurt (IPAC) / Caltech. For several years now, astronomers and cosmologists have been theoretically discussing the existence of an extra planet with a mass 10 times larger than that of Earth, located in the extreme …

A Hong Kong man has become the second confirmed patient to be infected with the coronavirus a second time, according to researchers from the University of Hong Kong. The finding suggests that some patients recovering from COVID-19, the disease caused by the coronavirus, may only have short-lived immunity to reinfection. …