Season's greetings! The Cone and Christmas Tree nebulae glow merrily in this lovely view submitted to National Geographic's Your Shot on December 17.
Hydrogen gas lit by a bright star inside the nebula explains the ruddy glow of the Christmas Tree Nebula.
Roughly 2,700 light-years away, the Cone Nebula (on the left) poses a bit of a puzzle to astronomers. They suspect that a powerful stellar wind from a compact star at the tip of the cone explains its shape.
Vermont Tepee Settles in for a Starry Night
A classic birch-bark, handmade Abenaki tepee rests under the star tracks filling a Vermont sky. Exposed to the winter nights of South Burlington, Vermont, the tepee photo was submitted in December by National Geographic Your Shot photographer Brian Drourr.
Hubble Wraps Up a Starry Ribbon
A holiday greeting from Hubble! The storied space telescope celebrates the season with this image of a starry explosion that resembles a holiday ribbon.
The knots in planetary nebula NGC 5189 each measure roughly the size of our solar system.
The ribbon shape of the nebula is sculpted by its central star, which wobbles as it rotates. "Reminiscent of a lawn sprinkler," the Hubble team says of the nebula image, the most-detailed look ever of this intriguing object.
Misty Fog Glows Over a State Forest
A misty field overlooked by the Milky Way glimmers in this summer picture, which was recently submitted to National Geographic's Your Shot.
The green gleaming above the edges of the horizon is known as airglow or nightglow, visible only to the most dark-adapted eyes. The planet's atmosphere glowing with a faint light causes the airglow, which is kin to the much brighter aurora.
Stars Dance Around Bright Gas Clouds
Lights dance in the young star cluster NGC 3572, seen in the nighttime sky above Chile. Youthful stars swirl amid gas clouds in this view.
Most stars form in such clusters, where gas clouds combine and are compressed by the explosive winds from the newborns. The circles and spikes surrounding the blue stars in this picture result from aberrations in the European Southern Observatory image's photographic process.
Supernova Burns Bright with X-Ray Bands
The remnants of the Cassiopeia A supernova burn brightly with x-rays revealed by NASA's Chandra X-ray Observatory. The star itself exploded some 330 years ago, making it one of the most recent supernovae in our galaxy.
Some 10,000 light-years away, the colors shown in this image reveal the strength of the x-rays emitted by the supernova remnant: red for low-energy ones, green for medium strength, and blue for the most powerful.