Astronomy Picture Of the Day (APOD)Tonight: A Blue Moon
How often does a full moon occur twice in a single month? Exactly once in a Blue Moon. In fact, the modern usage of the term "Blue Moon" refers to the second Full Moon in a single month. Tonight's Blue Moon will be the first since November 2001.
While enjoying the spaceweather on a gorgeous summer evening in mid-July, astronomer Philippe Moussette captured this colorful fish-eye lens view looking north from the Observatoire Mont Cosmos, Quebec, Canada, planet Earth. In the foreground, lights along the northern horizon give an orange cast to the low clouds.
Steep cliffs drop into the rugged terrain of Melas Chasma in this stunning view from the Mars Express spacecraft orbiting the Red Planet. At a scale of 16 meters per pixel, the image data...
A Cygnus Star Field
In the constellation of the swan near the nebula of the pelican lies the gas cloud of the butterfly surrounding a star known as the hen. That star, given the proper name Sadr, is visible to the unaided eye but found here as the brightest object on the upper left.
Razorbacks in Endurance Crater
Over one year after its launch, robot geologist Opportunity has been spending recent sols on Mars inching its way down the slopes of Endurance crater. Littered with martian blueberries, some flat rocks within the crater also seem to have surprising razorbacks -- narrow slabs sticking up along their edges.
A Large Active Region Crosses the Sun
An unexpectedly large sunspot region is now crossing the Sun. The active region is home to rivers of hot plasma, explosive flares, strong magnetic fields, a powerful Coronal Mass Ejection (CME), and a sunspot group so large it can be seen by the protected eye without magnification.
A Solar Filament Lifts Off
Hot gas frequently erupts from the Sun. One such eruption produced the glowing filament pictured above, which was captured in 2000 July by the Earth-orbiting TRACE satellite. The filament, although small compared...
A String Of Pearls
Comet Shoemaker-Levy 9, named after its co-discoverers, was often referred to as the "string of pearls" comet. It is famous for its suggestive appearance as well as its collision with the planet Jupiter!
Saturns Rings in Natural Color
What colors are Saturn's rings? Recent images from the Cassini spacecraft now orbiting Saturn confirm that different rings have slightly different colors. The above image shows their sometimes-subtle differences in brightness and color. The rings reflect sunlight and so, even if they were perfectly reflecting, would appear the color of the Sun.
In this alluring time exposure, star trails arc across the night sky above Monterey Bay and the lights of Santa Cruz, California, USA. But since the exposure began around 3:01am PDT on July 15 it also records the long trail of a Delta II rocket lofting NASA's Aura spacecraft into Earth orbit.