What created the Waterfall Nebula? The origin is still being researched. The structure, officially designated Herbig-Haro 222, appears in the region of NGC 1999 in the Great Orion Molecular Cloud complex. The elongated gaseous stream stretches about ten light years but appears similar to a long waterfall on Earth.

The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded. At the very center is a white dwarf star, the surviving core of a former Sun-like star.

How much of Jupiter's moon Europa is made of water? No one is sure, but probably a lot. Based on the Galileo probe data acquired during its exploration of the Jovian system from 1995 to 2003, Europa possesses a deep, global ocean of liquid water beneath a layer of surface ice.

How complex is Jupiter? NASA's Juno mission to Jupiter is finding the Jovian giant to be more complicated than expected. Jupiter's magnetic field has been discovered to be much different from our Earth's simple dipole field, showing several poles embedded in a complicated network more convoluted in the north than the south.

Is this a fossilized turtle on Mars? No. Although resembling a large Earth tortoise, this is a layered rock outcrop on Mars that is estimated to span about 15 meters, making it much larger than turtles on Earth.

No one on Earth sees the Moon rotate like this. That's because the Moon is tidally locked in synchronous rotation, showing only one side to denizens of our fair planet. Still, given modern...

It was one of the largest and longest lived storms ever recorded in our Solar System. First seen in late 2010, the featured cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet.

The Southern Crown (Corona Australis) dazzles with young and ancient celestial jewels. The Corona Australis Cloud is a collage of reflection and emission nebulae on the left of todayБs image. At 430 light years away, this cloud is one of the closest star-forming regions to Earth.

On August 12, the Moon's shadow reached out to touch our fair planet. Beginning in the Arctic Ocean, it swept along a narrow track that led the dark lunar umbra across parts of Greenland, Iceland, the Atlantic, Portugal, and northern Spain.

Where do comet tails come from? There are usually no obvious places on the nuclei of comets from which the jets that create comet tails emanate. One of the best images of emerging jets...