Astronomy Picture Of the Day (APOD)Blue Flash
Difficult to observe, the momentary green flash above the rising or setting sun has been documented as a phenomenon caused by the atmospheric bending or refraction of sunlight. Like a weak prism, the Earth's atmosphere breaks white sunlight into colors, bending red colors slightly and green and blue colors through increasingly larger angles.
Rich star fields and glowing hydrogen gas silhouette dense, opaque clouds of interstellar gas and dust in this Hubble Space Telescope close-up of IC 2944, a bright star forming region in Centaurus, 5,900 light-years away. The largest of these dark globules, first spotted by South African astronomer A. D.
The Mysterious Cone Nebula
Sometimes the simplest shapes are the hardest to explain. For example, the origin of the mysterious cone-shaped region seen on the far left remains a mystery. The interstellar formation, dubbed the Cone Nebula, is located about 2700 light years away.
M2 9: Wings of a Butterfly Nebula
Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.
Apollo 17 s Moonship
Awkward and angular looking, Apollo 17's lunar module Challenger was designed for flight in the vacuum of space. This sharp picture from the command module America, shows Challenger's ascent stage in lunar orbit.
M16: Infrared Star Hunt
The head of an interstellar gas and dust cloud is shown here in false-color, a near-infrared view recorded by astronomers hunting for stars within M16's Eagle Nebula. Made famous in a 1995 Hubble...
M16: Stars, Pillars and the Eagle s EGGs
The Hubble Space Telescope's 1995 image of pillars of dust and gas, light-years long, within the Eagle Nebula (M16) was sensational. The three prominent pillars in that close-up visible light picture also appear...
International Space Station Over Earth
High above a cloudy Earth, the International Space Station (ISS) orbits silently. The Space Shuttle Endeavor Crew took the above picture as they departed the space station in mid-December. Endeavor brought up three...
The Secret of the Black Aurora
What causes black aurora? These gaps in normal bright aurora are frequently recorded but rarely questioned. Recent research using data from four Cluster spacecraft orbiting the Earth has now likely found the secret: black auroras are actually anti-auroras.
A Year of Dark Cosmology
We live in the exciting time when humanity discovers the nature of our entire universe. During this year, in particular, however, the quest for cosmological understanding appears to have astronomers groping in the dark.