How Mars lost its fresh water

The surface of Mars once flowed with water fresh enough to sustain life, according to data collected by two of NASA's Martian rovers. The findings suggest freshwater rivers and streams once existed in the Meridiani Plains region near the Martian equator, 3.8 billion years ago. But all that changed when a huge asteroid impact turned the fresh water into a highly acidic soup.

Astronomers 'see' strands of cosmic web

Astronomers say they have for the first time seen the gas strands theorised to hold the universe together in a "cosmic web". Cosmologists believe that matter between galaxies is distributed in a network of strands known as the cosmic web. The vast majority of atoms in the universe are thought to reside in this web as hydrogen left over from the Big Bang, and galaxies are believed to form at network nodes. Until now, this web had never been seen. Small sections of it had been detected by its absorption of light from bright background sources, but those results didn't reveal its overall structure.

Fossil fish re-defines origins of walking

Fossils of a creature that looked part-fish and part-limbed animal, Tiktaalik roseae, the precursor to walking land animals, represents the best-known transitional species between fish and land-dwelling animals.

Scientists get Pre-RNA molecule to self-assemble

Chemists have found a way to make a pre-RNA molecule assemble itself in a pond-like setting — potentially suggesting a key step in how life originated. Pre-RNA is hypothesised to have eventually evolved via RNA in­to DNA.

“Impossibly” large stellar explosions identified

A newly identified type of stellar explosion breaks all the old rules — and records — for such explosions. The “superluminous” outbursts have been coming to scientists’ attention since the end of the last decade, but no one knew what they were at first. The new study proposes that the blasts are probably associated with the formation of a magnetar, an extraordinarily magnetized, dizzyingly fast-spinning neutron star.