Radio galaxies are cosmic beacons, with the brightest ones beaming nearly a trillion solar-luminosities of radiation into space at radio wavelengths. The origin of this intense emission ...

Mars, Jupiter, and all the other planets and asteroids in the night sky that are visible to us can be seen because they reflect sunlight. The "albedo" is the quantity that quantifies a b...

Near Earth Objects (NEOs) are small solar system bodies that are infamous because their orbits take them near earth's orbit; sometimes they pass dangerously close to the earth or even col...

Polaris, the North Star, is not only renowned as a reliable beacon for early navigators. It is a Cepheid variable star, that is, a star whose mass and age are just right to prompt periodi...

The sun's photosphere is hot, about 6000 kelvin, and so the sun emits about 70% of its light in the visible portion of the electromagnetic spectrum, and about one-quarter in the infrared....

The Smithsonian Astrophysical Observatory is pleased to announce that Dr. Giovanni Fazio will receive the 2008 Royal Society of London/COSPAR Massey award for outstanding contributions to...

The sun's family of planets, including the Earth, as well as its other companions like comets, all formed from a disk of material that was present in the early days of the solar system. ...

Gamma-rays are the most energetic known form of light (that is, of electromagnetic radiation). A gamma ray is by definition at least a hundred thousand times more energetic than an optic...

Saint Louis, MO We live in the Milky Way galaxy - a disk-shaped collection of about 400 billion stars including the Sun. Many of those stars and much of the dense gas between the stars c...

Saint Louis, MO