When faraway stars explode, they send out flashes of energy called gamma-ray bursts that are bright enough that telescopes back on Earth can detect them. Studying these pulses, which can also come from mergers of some exotic astronomical objects such as black holes and neutron stars, can help astronomers like me understand the history of the universe.

Space telescopes detect on average one gamma-ray burst per day, adding to thousands of bursts detected throughout the years, and a community of volunteers are making research into these bursts possible.

On Nov. 20, 2004, NASA launched the Neil Gehrels Swift Observatory, also known as Swift. Swift is a multiwavelength space telescope that scientists are using to find out more about these mysterious gamma-ray flashes from the universe.

Gamma-ray bursts usually last for only a very short time, from a few seconds to a few minutes, and the majority of their emission is in the form of gamma rays, which are part of the light spectrum that our eyes cannot see.

You may have flown a flight simulator in a computer game or at a science museum. Landing without crashing is always the hardest part. But that's nothing compared to the challenge that engineers are facing to develop a flight simulation of the very large vehicles necessary for humans to explore the surface of Mars. The Red Planet poses innumerable challenges to astronauts, not the least of which is getting there.

NASA confirmed Monday that a mystery object that crashed through the roof of a Florida home last month was a chunk of space junk from equipment discarded at the International Space Station.