Astronomy Picture Of the Day (APOD)Pandora Close up at Saturn
What do the craters of Saturn's small moon Pandora look like up close? To help find out, NASA sent the robotic Cassini spacecraft, now orbiting Saturn, past the unusual moon two weeks ago. The highest resolution image of Pandora ever taken was then captured from about 40,000 kilometers out and is featured here.
Comet 45P Returns
An old comet has returned to the inner Solar System. Not only is Comet 45P/HondaMrkosPajduАkovА physically ancient, it was first discovered 13 orbits ago in 1948. Comet 45P spends most of its time out near the orbit of Jupiter and last neared the Sun in 2011.
A Full Sky Aurora Over Norway
Higher than the highest building, higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking molecules in the Earth's atmosphere.
The Trifid Nebula, also known as Messier 20, is easy to find with a small telescope, a well known stop in the nebula rich constellation Sagittarius. But where visible light pictures show the nebula...
Tidally locked in synchronous rotation, the Moon always presents its familiar nearside to denizens of planet Earth. From lunar orbit, the Moon's farside can become familiar, though. In fact this sharp picture, a mosaic from the Lunar Reconnaissance Orbiter's wide angle camera, is centered on the lunar farside.
Shell Game in the LMC
An alluring sight in southern skies, the Large Magellanic Cloud (LMC) is seen here through narrowband filters. The filters are designed to transmit only light emitted by ionized sulfur, hydrogen, and oxygen atoms. Ionized...
Curiosity Surveys Lower Mount Sharp on Mars
If you could stand on Mars -- what might you see? If you were the Curiosity rover, then just last month you would have contemplated the featured image -- a breathtaking panorama of the lower portion of Mount Sharp. The colors have been adjusted to mimic lighting familiar to Earthlings.
M31: The Andromeda Galaxy
What is the nearest major galaxy to our own Milky Way Galaxy? Andromeda. In fact, our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it.
NGC 6357: Stellar Wonderland
For reasons unknown, NGC 6357 is forming some of the most massive stars ever discovered. This complex wonderland of star formation consists of numerous filaments of dust and gas surrounding huge cavities of massive star clusters. The intricate patterns are caused by complex interactions between interstellar winds, radiation pressures, magnetic fields, and gravity.
The Magnificent Horsehead Nebula
Sculpted by stellar winds and radiation, a magnificent interstellar dust cloud by chance has assumed this recognizable shape. Fittingly named the Horsehead Nebula, it is some 1,500 light-years distant, embedded in the vast Orion cloud complex.