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

Cosmic rays are very rapidly moving nuclear particles that impact the earth from space, and generally originate from well beyond the solar system. The energies of these particles can be m...

Cambridge, MA

Cambridge, MA On April 9, the Sun erupted and blasted a bubble of hot, ionized gas into the solar system. The eruption was observed in unprecedented detail by a fleet of spacecraft, reve...

Galaxies frequently collide with one another, leaving evidence for their stupendous interactions nearly everywhere in the sky. Our own Milky Way galaxy, for example, is heading towards it...