Two NASA satellites were launched Friday from Vandenberg Air Force Base, Calif., on missions to reveal the inner secrets of clouds and aerosols, tiny particles suspended in the air.

“Clouds are a critical but poorly understood element of our climate,” said Dr. Graeme Stephens, CloudSat principal investigator and a professor at Colorado State University, Fort Collins, [...]

Many galaxies reside in galaxy groups, where they experience close encounters with their neighbours and interact gravitationally with the dark matter – mass which permeates the whole intergalactic space but is not directly visible because it doesn’t emit radiation.

These interactions cause large galaxies to spiral slowly towards the centre of the group, where they can [...]

Andy, Bob, and Charles play as a team.

Everyone is asked one of two questions: “What is the value of X” or “What is the value of Y?”

Only two answers are allowed: +1 or -1.

Either everyone is asked the first question, or one player is asked the first question and two players are asked the second [...]

When the sun’s rays shine on bare desert regions, there are no perennial grasses to insulate the rocks and soil from absorbing the heat of the sun, and the top inch of bare soil can reach 120 degrees Fahrenheit or more. The bare rocks and soil absorb the sun’s heat, which in turn heats the [...]