Category Astronomy/Space

For >30 years, scientists have argued about a controversial hypothesis relating to periodic mass extinctions and impact craters – caused by comet and asteroid showers – on Earth. Now scientists have concluded that mass extinctions occurring over the past 260 million years were likely caused by comet and asteroid showers.

A graph showing how the rate of cratering has changed on Earth over time. The arrows indicate the dates of mass extinctions. Credit: Michael Rampino / NYU

Michael Rampino, NYU geologist, and Ken Caldeira, a scientist in the Carnegie Institution’s Department of Global Ecology, offer new support linking the age of these craters with recurring mass extinctions of life, including the demise of the dinosaurs...

An artist’s impression of the innumerable Earth-like planets that have yet to be born over the next trillion years in the evolving universe. Credit: NASA / ESA / G. Bacon (STScI)

Earth came early to the party in the evolving universe. According to a new theoretical study, when our solar system was born 4.6 B years ago only 8% of the potentially habitable planets that will ever form in the universe existed. And, the party won’t be over when the sun burns out in another 6B years. The bulk of those planets – 92% – have yet to be born.

This conclusion is based on an assessment of data collected by NASA’s Hubble Space Telescope and the prolific planet-hunting Kepler space observatory...

The Kepler space telescope’s planet-hunting mission was launched in 2009 but lost its key orientation abilities in 2013

Mysterious light on a distant star could be a sign of alien civilisation, some astronomers have claimed, stirring controversy. Not so fast, said NASA.

“The mysterious star, KIC 8462852, does have an odd light curve,” said Steve Howell, working on the Kepler space telescope’s planet-hunting mission. “It does not look like a normal exoplanet or binary star light curve. However, I think that saying that it immediately is alien is a bit of a stretch,” Howell said in an email to AFP.

Kepler observes distant planets and stars by observing transits, or the dimming of light when another celestial body passes in front...