Astronomy Picture Of the Day (APOD)A White Battle in the Black Sea
Trillions have died in the Earth's seas. Calcified shields of the dead already make up the white cliffs of Dover. The battle between ball-shaped light-colored single-celled plants -- phytoplankton called coccolithophores -- and even smaller, diamond-shaped viruses dubbed coccolithoviruses -- has raged for tens of millions of years.
The Holographic Principle
Is this picture worth a thousand words? According to the Holographic Principle, the most information you can get from this image is about 3 x 10 65 bits for a normal sized computer monitor.
Between the Rings
On April 12, as the Sun was blocked by the disk of Saturn the Cassini spacecraft camera looked toward the inner Solar System and the gas giant's backlit rings. At the top of the mosaicked view is the A ring with its broader Encke and narrower Keeler gaps visible.
NGC 4302 and NGC 4298
Seen edge-on, spiral galaxy NGC 4302 (left) lies about 55 million light-years away in the well-groomed constellation Coma Berenices. A member of the large Virgo Galaxy Cluster, it spans some 87,000 light-years, a little smaller than our own Milky Way.
Asteroid 2014 JO25
A day before its closest approach, asteroid 2014 JO25 was imaged by radar with the 70-meter antenna of NASA's Goldstone Deep Space Communications Complex in California. This grid of 30 radar images, top left to lower right, reveals the two-lobed shape of the asteroid that rotates about once every five hours.
The Red Spider Planetary Nebula
Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star.
What glows in the night? This night, several unusual glows were evident -- some near, but some far. The foreground surf glimmers blue with the light of bioluminescent plankton. Next out, Earth's atmosphere dims the horizon and provides a few opaque clouds. Further out, the planet Venus glows bright near the image center.
Two Million Stars on the Move
If you could watch the night sky for one million years -- how would it change? Besides local effects caused by the Earth's spin and the reorientation of the Earth's spin axis, the stars themselves will move.
Life Enabling Plumes above Enceladus
Does Enceladus have underground oceans that could support life? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, was originally unknown.
Luminous Salar de Uyuni
A scene in high contrast this thoughtful night skyscape is a modern composition inspired by M. C. Escher's lithograph Phosphorescent Sea. In it, bright familiar stars of Orion the Hunter and Aldebaran, eye of Taurus the Bull, hang in clear dark skies above a distant horizon.