Welcome to planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the […]

Variable star R Aquarii is actually an interacting binary star system, two stars that seem to have a close symbiotic relationship. Centered in this space-based optical/x-ray composite image it lies […]

Even though Jupiter was the only planet visible in the evening sky on February 2, it shared the twilight above the western horizon with the Solar System’s brightest moons. In […]

Even though Venus (left) was the brightest planet in the sky it was less than 1/30th the apparent size of the Moon on January 29. But as both rose before […]

What’s happening at the center of our galaxy? It’s hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, […]

What will the Moon phase be on your birthday this year? It is hard to predict because the Moon’s appearance changes nightly. As the Moon orbits the Earth, the half […]

The Great Carina Nebula is home to strange stars and iconic nebulas. Named for its home constellation, the huge star-forming region is larger and brighter than the Great Orion Nebula […]

How can gas float above the Sun? Twisted magnetic fields arching from the solar surface can trap ionized gas, suspending it in huge looping structures. These majestic plasma arches are […]

Named for the southern constellation toward which most of its galaxies can be found, the Fornax Cluster is one of the closest clusters of galaxies. About 62 million light-years away, […]

The Mare Orientale, Latin for Eastern Sea, is one of the most striking large scale lunar features. The youngest of the large lunar impact basins it’s very difficult to see […]