The space between stars is not empty - it contains copious amounts of gas and dust. Astronomers estimate that about 5-10% of the total mass of our Milky Way galaxy is contained in the int...

At the core of most galaxies including our own Milky Way is a massive black hole. Material falling into the environment of the black hole heats up, and can radiate dramatically, sometimes...

Not all stars are created equal. Although all of them are born mostly with hydrogen, the trace amounts of other elements present can vary by at least a factor of ten, depending on the pa...

Cambridge, MA Few nighttime sights offer more drama than the full Moon rising over the horizon. Now imagine that instead of the Moon, a gas giant planet spanning three times more sky loo...

For over a decade astronomers have been probing a region of the northern sky, not far from the handle of the Big Dipper, that is relatively free of bright stars and the diffuse glow of t...

Searches for interstellar molecular oxygen, O2,have a long history, andthe motivation for these searches has evolved. Prior to the late 1990’s, efforts to detect O2 were driven by a desir...

Anchorage, AK Building a terrestrial planet requires raw materials that weren't available in the early history of the universe. The Big Bang filled space with hydrogen and helium. Chemic...

Cambridge, MA New evidence from NASA's Chandra X-ray Observatory challenges prevailing ideas about how supermassive black holes grow in the centers of galaxies. Astronomers long have tho...

Seyfert galaxies are like normal galaxies, our own Milky Way included, except in one critical respect: their nuclei are fantastically bright. In some instances they are as luminous as 10...

On June 5, 2012, a rare event occurred - the planet Venus traversed the disk of the Sun, an event called a Venus transit. Because of the geometry of the orbits of Venus and the Earth, Ve...