Like an ominous fog swirling around a street lamp, a nebula 1,499 light-years away in the constellation Orion burns dimly, illuminated by hot, massive stars embedded inside the gas cloud.
The Hubble Space Telescope snapped this image of NGC 1999, also known as the Keyhole nebula, back in 1999.
The creepy dark shape at the center of the image is actually a dim cloud of gas and dust that astronomers believe is a nursery for newborn stars.
Image courtesy NASA and The Hubble Heritage Team (STScI)
Dark shadows (at left) appear have flailing arms as they flee some unknown menace in this image of an isolated dark nebula some 1,200 light-years from Earth in the northern constellation Cepheus—the King.
Known as Sharpless 2-136, this galactic ghost formation is the site of intense star and planet formation and stretches about two light-years across.
Image courtesy Adam Block/NOAO/AURA/NSF
What looks like the legendary Frankenstein's monster, glaring with wild, piercing eyes, is actually a colorful cloud of gas and dust surrounding clusters of young stars.
Located some 20,000 light-years from Earth in the southern constellation Puppis, hundreds of hot, massive stars sit huddled together and belch out strong radiation into space. The outbursts ionize the molecules in the surrounding gas clouds and light them up in ghoulish colors.
Nicknamed the Black Widow Nebula, the cloud is teeming with clusters of massive young stars, seen as yellow specks in the center of this frame. Radiation from the stars is blowing the surrounding gas into two opposing bubbles, forming the bulbous body and spindly legs of the cosmic crawler.
The Black Widow is just one of the ghastly bodies littering the heavens that's included in our Halloween round-up of the top ten spooky space objects, as chosen by National Geographic editors.
In 2008 astronomers using the Hubble Space Telescope revealed that they had gazed into the Lidless Eye of the Dark Lord Sauron—and found a new planet.
Despite its eerie resemblance to the Lord of the Rings icon, the frame above actually shows a Hubble picture of Fomalhaut, a bright southern star about 25 light-years from Earth. The fiery "iris" is a ring of planet-forming material that surrounds the star, and a small bright speck embedded in the ring is the Jupiter-like planet Fomalhaut b.
The image was the first visible-light snapshot of a planet orbiting another star.
Image courtesy P. Kalas, U.C. Berkeley/ESA/NASA
Hot rocks rain from the sky, and oceans of lava ooze across one side while sunlight never shines on the other. Welcome to Hell, aka, the alien planet CoRoT-7b. Initially described in 2009, the weird world was the first rocky planet found outside our solar system.
But unlike Earth, CoRoT-7b orbits just 1.5 million miles (2.5 million kilometers) away from its star—about 23 times closer than Mercury is to our sun. The planet is also tidally locked, so that one side always faces the star while the other side lies in constant darkness.
Astronomers calculate that the surface of the star-facing side is a broiling 4,220 degrees Fahrenheit (2,327 degrees Celsius).
Illustration courtesy L. Calçada, ESO
A Blood Moon hangs over an autumn landscape in Sweden on October 11.
Also known as the Hunter's Moon, the Blood Moon is the first full moon after the Harvest Moon, which usually appears around the fall equinox. Around this time of year in the Northern Hemisphere, the moon rises a bit earlier than usual. It's thought the monikers arose because the fall full moons provided plentiful light for hunters tracking prey after sunset.
When a sunlike star dies, it swells up and eventually sheds its outer layers of gas, leaving behind a corpse known as a white dwarf. But sometimes the stellar dead come back to life by feeding from nearby companions.
Such "zombie" stars are known to astronomers as Type Ia supernovae, violent explosions that happen when white dwarfs consume so much material from neighbors that they reach a defined mass limit and explode.
Last March astronomers with the European Southern Observatory peered into a dark corner of the constellation Orion and snapped a new picture of a cosmic bat, the nebula NGC 1788.
Unlike nebulae that shine due to their own heated gases, this cloud gets its ghostly glow because its cold gas and dust are reflecting and scattering light from the young stars hidden inside.
This image, taken from ESO's La Silla Observatory in Chile, combines three wavelengths of visible light to reveal the bat's bright face flanked by faint spreading wings.
Image courtesy ESO
Black Hole Cannibal
Deep in the dark heart of the galaxy NGC 3393, two monsters are eating each other in an epic clash of the titans.
In August scientists with NASA's Chandra X-ray Observatory released this composite image of the spiral galaxy that shows not one but two supermassive black holes in its middle, separated by just 490 light-years.
Backyard astronomers often make friends with the Little Ghost Nebula, officially known as NGC 6369. The object can be seen from Earth as a faint cloud surrounding the corpse of a dead star in the constellation Ophiuchus.
In this 2004 Hubble Space Telescope picture, the nebula can be seen in greater detail, revealing the evolution of gas being ejected from the dying star.
As ultraviolet radiation pours from the star, it strips electrons from atoms in the gas, ionizing—electrically charging—the closest regions and creating the bright, blue-green ring. Redder areas on the outer edges of the nebula are places where ionization is less advanced.
Image courtesy ESA/NASA
The Death Star
Despite this small moon's ominous appearance, the Millennium Falcon would have nothing to fear from Mimas, a member of Saturn's family of natural satellites.
The huge crater that led to Mimas's Star Wars nickname is called Herschel. At about 80 miles (130 kilometers) across, the crater covers roughly a third of the moon's diameter.
In fact, astronomers think the impact that formed the basin must have come close to shattering the 250-mile-wide (400-kilometer-wide) moon.
(Also see "The Star Wars Worlds: More Science Than Fiction?")
Image courtesy SSI/NASA
Twilight fans take note: Scattered across our Milky Way galaxy are vampires that truly sparkle—so-called blue straggler stars that maintain the appearance of youth by sucking the life from other stars.
Blue stragglers are often found in dense star clusters. These tight bundles are thought to contain stars that all formed around the same time, and the majority of the stars in such clusters are among the oldest in the galaxy.
But the stragglers have a blue tinge to their light that suggests youth among stellar populations. Scientists think the vampires are stealing gases from their neighbors, allowing the small, aging stars to swell in mass and extend their lives by hundreds of millions of years.