Universe

What everybody ought to know about galaxies!

A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.   What are galaxies? The word galaxy is derived from the Greek galaxias, literally “milky”, a reference to the Milky Way. Galaxies range in size [ … ]

What is the Space Launch System (SLS)?

The Space Launch System (SLS) is an American Space Shuttle-derived heavy expendable launch vehicle. It is part of NASA’s deep space exploration plans including a manned mission to Mars.   What is the Space Launch System (SLS)? [ … ]