The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun. It can be quite ...
The past week brought some spectacular aurora to northern skies. These aurorae were caused by a large interplanetary shock wave that exploded from the Sun on April 4. When the shock wave reached the Earth on April 6, the resulting aurora could ...
Pluto is the only planet in our Solar System remaining unphotographed by a passing spacecraft. Distant Pluto and its moon Charon therefore remain somewhat mysterious. In addition to direct imaging by the Hubble Space Telescope, careful tracking ...
Nine years ago the massive Compton Gamma Ray Observatory was deployed in low earth orbit. Sparkling interior reflections and the bright limb of the Earth are visible in this 1991 window view of Compton's release by the crew of the Space Shuttle ...
Planetary nebulae do look simple, round, and planet-like in small telescopes. But images from the orbiting Hubble Space Telescope have become well known for showing these fluorescent gas shrouds of dying Sun-like stars to possess a staggering ...
Rising before the Sun on February 2nd, astrophotographer Joe Orman anticipated this apparition of the bright morning star Venus near a lovely crescent Moon above a neighbor's house in suburban Phoenix, Arizona, USA. Fortunately, the alignment of ...
M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of Scorpius. M7 contains about 100 stars in total, is ...
What's lighting up the Cigar Galaxy? M82, as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas, however. Recent ...
A huge eruptive prominence is seen moving out from our Sun in this condensed half-hour time-lapse sequence. Ten Earths could easily fit in the "claw" of this seemingly solar monster. This large prominence, though, is significant not only for ...
Star forming regions known as "EGGs" are uncovered at the end of this giant pillar of gas and dust in the Eagle Nebula (M16). EGGs, short for evaporating gaseous globules, are dense regions of mostly molecular hydrogen gas that fragment and ...