A Total Solar Eclipse Over China
5.08.2008

What's that black dot over the Sun? The Moon. This past weekend, the Sun went dark during the day as the Moon completely covered it. The total solar eclipse was visible over a thin swath of Earth extending from northern Canada to China.

Cutaway Callisto: Ice, Rock, and Ocean
6.11.1998

Cruising past the moons of reigning gas giant Jupiter, Voyager and Galileo have returned tantalizing evidence for a liquid water ocean beneath the surface of Europa. Now researchers are reporting telltale indications that the battered Jovian moon Callisto may also harbor a subsurface

Sunset, Moonset, Taj Mahal
27.10.2022

On October 25th, Sun and New Moon set together as seen from Agra, India. Their close conjunction near the western horizon, a partial solar eclipse, was captured in this elevated view in hazy skies near the solitary dome of the Taj Mahal.

APOD: 2025 September 7 Б All the Water on Planet Earth
7.09.2025

How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius.

Lunar Module at Taurus Littrow
28.06.2002

Can the Hubble Space Telescope take a picture that shows the Apollo lunar modules on the Moon? With its 2.4 meter diameter mirror, the smallest object that the Hubble can resolve at the Moon's distance of around 400,000 kilometers is about 80 meters across.

Jupiters Europa from Spacecraft Juno
3.10.2022

What mysteries might be solved by peering into this crystal ball? In this case, the ball is actually a moon of Jupiter, the crystals are ice, and the moon is not only dirty but cracked beyond repair. Nevertheless, speculation is rampant that oceans exist under Europa's fractured ice-plains that could support life.

Ring of Fire Revisited
30.05.2003

Early on Saturday, May 31 (UT) the new Moon will once again slide across the Sun's fiery disk, and once again an annular solar eclipse will be the result -- since the Moon's apparent diameter will be a little too small to completely cover the Sun.

Moondog Night
10.12.2014

In this night scene from the early hours of November 14, light from a last quarter Moon illuminates clouds above the mountaintop domes of Kitt Peak National Observatory near Tucson, Arizona. Bright Jupiter...

APOD: 2025 February 9 Б Milky Way over the Australian Pinnacles
9.02.2025

What strange world is this? Earth. In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia. Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains unknown.

Enceladus and the Search for Water
10.03.2006

Based on data from Cassini spacecraft instruments, researchers are now arguing that liquid water reservoirs exist only tens of meters below the surface of Saturn's small (500 kilometer diameter) but active moon Enceladus. The exciting new results center around towering jets and plumes of material erupting from the moon's surface.