Astronomy Picture of the Day

2011-03-27

The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By ...

2011-03-26 Adam Block

The yellowish star near center in this remarkable telescopic skyview is T Tauri, prototype of the class of T Tauri variable stars. Nearby it is a dusty yellow cosmic cloud historically known as Hind's Variable Nebula (NGC 1555). Over 400 ...

2011-03-25 Kwon, O Chul

Intense auroral activity flooded the night with shimmering colors on February 24, captured here from a lodge near the city of Yellowknife in northern Canada. The stunning sequence (left to right) of three all-sky exposures, taken at 30 second ...

2011-03-24 Dennis Di Cicco

Last week's Full Moon was hard to miss. Rising on March 19, its exact full phase occurred within an hour of perigee, the closest point in the Moon's orbit to Earth. As a result it appeared some 14 percent larger and 30 percent brighter than a ...

2011-03-23 Peter Tuthill

What could cause a nebula to appear square? No one is quite sure. The hot star system known as MWC 922, however, appears to be embedded in a nebula with just such a shape. The above image combines infrared exposures from the Hale Telescope on ...

2011-03-22

The universe is filled with galaxies. But to see them astronomers must look out beyond the stars of our galaxy, the Milky Way. For example, consider this colorful telescopic view of spiral galaxy NGC 6384, about 80 million light-years away in the ...

2011-03-21

How could part of the early universe be so cold? No one is sure, and many astronomers now think that the CMB Cold Spot on the cosmic microwave background (CMB) radiation is not particularly noteworthy. As the early universe expanded and cooled, ...

2011-03-20 Anthony Ayiomamitis

Did you see the Full Moon last night? Near the horizon, the lunar orb may have seemed to loom large, swollen in appearance by the famous Moon illusion. But the Full Moon really was a large Full Moon last night, reaching its exact full phase ...

2011-03-19 R Jay Gabany

Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend ...

2011-03-18 Göran Strand

When warm sunset hues begin to fade, two celestial beacons now shine in the evening twilight, Mercury and Jupiter. Wandering away from the Sun in planet Earth's sky, Mercury will offer good views this month as spring approaches in the northern ...