Described at times as a big blue marble, from some vantage points Earth looks more like a small blue marble. Such was the case in this iconic image of the Earth and Moon system taken by the Chang'e 5-T1 mission last week. The Moon appears larger than the Earth because it was much closer to the spacecraft's camera. Displaying much of a surface usually hidden from Earth, the Moon appears dark and gray when compared to the more reflective and colorful planet that it orbits. The robotic Chang'e 5-T1 spacecraft, predominantly on an engineering test mission, rounded the Moon last Tuesday returned to Earth on Friday.

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display. Arms went high in the air, patience and experience paid off, and the amazing featured image was captured. The setting is a summit of the Austnesfjorden fjord close to the town of Svolvear on the Lofoten islands in northern Norway. The time was early March. Our Sun has been producing an abundance of picturesque aurora of late as it is near the time of its maximum surface activity in its 11-year magnetic cycle.

When orbiting Saturn, be sure to watch for breathtaking superpositions of moons and rings. One such picturesque vista was visible recently to the robot Cassini spacecraft now orbiting Saturn. In 2006 April, Cassini captured Saturn's A and F rings stretching in front of cloud-shrouded Titan. Near the rings and appearing just above Titan was Epimetheus, a moon which orbits just outside the F ring. The dark space in the A ring is called the Encke Gap, although several thin knotted ringlets and even the small moon Pan orbit there. APOD Wall Calendar: Moons and Planets

October 31, 1938 was the day after Martians encountered planet Earth, and everything was calm. Reports of the invasion were revealed to be part of a Halloween radio drama, the now famous broadcast based on H.G. Wells' scifi novel War of the Worlds. On Mars October 20, 2014 was calm too, the day after its close encounter with Comet Siding Spring. Not a hoax, this comet really did come within 86,700 miles or so of Mars, about 1/3 the Earth-Moon distance. Earth's spacecraft and rovers in Mars orbit and on the surface reported no ill effects though, and had a ringside seat as a visitor from the outer solar system passed by. Spanning over 2 degrees against stars of the constellation Ophiuchus, this colorful telescopic snapshot captures our view of Mars on the day after. Bluish star 51 Ophiuchi is at the upper right and the comet is just emerging from the Red Planet's bright glare.

October 31, 1938 was the day after Martians encountered planet Earth, and everything was calm. Reports of the invasion were revealed to be part of a Halloween radio drama, the now famous broadcast based on H.G. Wells' scifi novel War of the Worlds. On Mars October 20, 2014 was calm too, the day after its close encounter with Comet Siding Spring. Not a hoax, this comet really did come within 86,700 miles or so of Mars, about 1/3 the Earth-Moon distance. Earth's spacecraft and rovers in Mars orbit and on the surface reported no ill effects though, and had a ringside seat as a visitor from the outer solar system passed by. Spanning over 2 degrees against stars of the constellation Ophiuchus, this colorful telescopic snapshot captures our view of Mars on the day after. Bluish star 51 Ophiuchi is at the upper right and the comet is just emerging from the Red Planet's bright glare.

A mysterious formation known as Devils Tower rises into the dark above northeastern Wyoming's prairie landscape in this 16 frame panoramic view. Seen against the night sky's thin, pale clouds and eerie green airglow, star clusters and nebulae of the Milky Way arc toward the galaxy's central realm at right. Of course the scene contains the Milky Way's own haunting and grisly visages of halloween, including ghosts, a flaming skull, a glowing eye and a witch's broom. To find them, slide your cursor over the picture or just follow this link, if you dare. And have a safe and Happy Halloween!

Frightening forms and scary faces are a mark of the Halloween season. They also haunt this cosmic close-up of the eastern Veil Nebula. The Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape and covers nearly 3 degrees on the sky in the constellation Cygnus, this portion of the eastern Veil spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's estimated distance, a reassuring 1,400 light-years from planet Earth. In the composite of image data recorded through broad and narrow band filters, emission from hydrogen atoms in the remnant is shown in red with strong emission from oxygen atoms in blue-green hues. Of course, in the western part of the Veil lies another seasonal apparition, the Witch's Broom.

Frightening forms and scary faces are a mark of the Halloween season. They also haunt this cosmic close-up of the eastern Veil Nebula. The Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape and covers nearly 3 degrees on the sky in the constellation Cygnus, this portion of the eastern Veil spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's estimated distance, a reassuring 1,400 light-years from planet Earth. In the composite of image data recorded through broad and narrow band filters, emission from hydrogen atoms in the remnant is shown in red with strong emission from oxygen atoms in blue-green hues. Of course, in the western part of the Veil lies another seasonal apparition, the Witch's Broom.

Sometimes your eclipse viewing goes bad in an interesting way. While watching and photographing last Thursday's partial solar eclipse, a popular astronomy blogger suffered through long periods of clouds blocking the Sun. Unexpectedly, however, a nearby cloud began to show a rare effect: iridescence. Frequently part of a more familiar solar corona effect, iridescence is the diffraction of sunlight around a thin screen of nearly uniformly-sized water droplets. Different colors of the sunlight become deflected by slightly different angles and so come to the observer from slightly different directions. This display, featured here, was quite bright and exhibited an unusually broad range of colors. On the right, the contrails of an airplane are also visible. APOD Wall Calendar: Weather and Volcanoes

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun. During the most recent such pass starting late last year, Mars as usual, loomed large and bright. Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion. Featured here is a series of images digitally stacked so that all of the stars coincide. Here, Mars appears to trace out a narrow loop in the sky. At the center of the loop, Earth passed Mars and the retrograde motion was the highest. Retrograde motion can also be seen for other Solar System planets. APOD Wall Calendar: Moons and Planets

What's that in front of the Sun? The closest object is an airplane, visible just below the Sun's center and caught purely by chance. Next out are numerous clouds in Earth's atmosphere, creating a series of darkened horizontal streaks. Farther out is Earth's Moon, seen as the large dark circular bite on the upper right. Just above the airplane and just below the Sun's surface are sunspots. The main sunspot group captured here, AR 2192, is one of the largest ever recorded and has been crackling and bursting with flares since it came around the edge of the Sun early last week. Taken last Thursday, this show of solar silhouettes was unfortunately short-lived. Within a few seconds the plane flew away. Within a few minutes the clouds drifted off. Within a few hours the partial solar eclipse of the Sun by the Moon was over. Only the sunspot group remains, but within a few more days even AR 2192 will disappear around the edge of the Sun. Fortunately, when it comes to the Sun, even unexpected alignments are surprisingly frequent. Gallery: Last Thursday's Partial Solar Eclipse

What would you see if you went right up to a black hole? Featured is a computer generated image highlighting how strange things would look. The black hole has such strong gravity that light is noticeably bent towards it - causing some very unusual visual distortions. Every star in the normal frame has at least two bright images - one on each side of the black hole. Near the black hole, you can see the whole sky - light from every direction is bent around and comes back to you. The original background map was taken from the 2MASS infrared sky survey, with stars from the Henry Draper catalog superposed. Black holes are thought to be the densest state of matter, and there is indirect evidence for their presence in stellar binary systems and the centers of globular clusters, galaxies, and quasars. Gallery: Thursday's Partial Solar Eclipse