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Early Mars was covered in ice sheets, not flowing rivers, researchers say
A large number of the valley networks scarring Mars's surface were carved by water melting beneath glacial ice, not by free-flowing rivers as previously thought, according to new research. The findings effectively throw cold water on the dominant 'warm and wet ancient Mars' hypothesis, which postulates that rivers, rainfall and oceans once existed on the red planet.
Ancient part of immune system may underpin severe COVID
New genetic and patient analyses suggest severe COVID is linked to overactive complement, one of the immune system's oldest branches, and excess blood clotting.
NASA astronauts safely splash down after first commercial crew flight to space station
Two NASA astronauts splashed down safely in the Gulf of Mexico Sunday for the first time in a commercially built and operated American crew spacecraft, returning from the International Space Station to complete a test flight that marks a new era in human spaceflight.
Cooling of Earth caused by eruptions, not meteors
Ancient sediment found in a central Texas cave appears to solve the mystery of why the Earth cooled suddenly about 13,000 years ago.
NASA data helps new model predict big solar flares
Scientists have developed a new model that successfully predicted seven of the Sun's biggest flares from the last solar cycle, out of a set of nine. With more development, the model could be used to one day inform forecasts of these intense bursts of solar radiation.