Ganymede from Juno
14.06.2021

What does the largest moon in the Solar System look like? Jupiter's moon Ganymede, larger than even Mercury and Pluto, has an icy surface speckled with bright young craters overlying a mixture of older, darker, more cratered terrain laced with grooves and ridges.

Unwinding M51
6.04.2024

The arms of a grand design spiral galaxy 60,000 light-years across are unwound in this digital transformation of the magnificent 2005 Hubble Space Telescope portrait of M51. In fact...

APOD: 2026 June 28 Б AR 4478: Giant Sunspot Group
28.06.2026

Right now, one of the largest sunspot groups in recent history is crossing the Sun. Active Region 4478 is not only big -- it's violent, showing tangled magnetic fields capable of throwing off huge clouds of particles into the Solar System. Some of these CMEs might impact the Earth.

Highlights of the Summer Sky
27.06.2018

What can you see in the night sky this summer? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) summer sky events fan out toward the left, while late summer events are projected toward the right.

Fly Me to the Moons
25.02.2013

Sometimes the Moon is a busy direction. Last week, for example, our very Moon passed in front of the planet Jupiter. While capturing this unusual spectacle from New South Wales, Australia, a quick-thinking astrophotographer...

Extrasolar Super Earth Gliese 1214b Might Hold Water
10.09.2013

Might this distant planet hold water? Actually, given how close Gliese 1214b is to its parent star, any water, if it exists, would surely be in the form of steam. In the above artist...

APOD: 2024 April 3 Б Unusual Nebula Pa 30
3.04.2024

What created this unusual celestial firework? The nebula, dubbed Pa 30, appears in the same sky direction now as a bright "guest star" did in the year 1181. Although Pa 30's filaments look...

Saturns Hexagon and Rings
20.02.2013

Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere else in the Solar System.

Wonder and Mystery above the Very Large Telescopes
9.05.2011

What's that bright orange dot above the large telescope on the right? Even seasoned sky enthusiasts might ponder the origin of the orange orb seen by scrolling across this panoramic image, taken last December. Perhaps identifying known objects will help.

Comet Hyakutake Finder Chart for Early April
31.03.1996

During April Comet Hyakutake heads in toward the Sun after passing the Earth. At this time the comet's orbit places it north of the Earth. Remaining visible in the northern sky as it nears the Sun, it will set progressively earlier in the evening.