Space Pictures This Week: Birth of a Star, Moon Lineup

Moon Roundup

Photograph courtesy NASA/JPL-Caltech  

Future astronauts looking up at the Martian night sky will see not one, but two moons gliding across the overhead sky.

This illustration shows the size comparison of the two moons, Diemos, at the far left and Phobos, as seen from the Martian surface,  alongside with Earth's moon as it appears from the surface of Earth.

On August 1, NASA's Curiosity rover captured both moons flying across the overhead sky together. At the time the rover snapped the images, 7.5-mile-wide (12-kilometer-wide) Deimos was 12,800 miles (20,500 kilometers) in altitude, while 14-mile-wide (22-kilometer-wide) Phobos was much closer at only 3,900 miles (6,240 kilometers) from the rover.

In contrast, Earth's moon has a diameter of 2,159 miles (3,474 kilometers) and is on average 238,000 miles (380,000 kilometers) away from Earth.

Published August 23, 2013

Falling Stars

Photograph by L. Starwisper, National Geographic Your Shot  

Like a pair of falling stars, meteors streak through the sky above Jiangxi, China, during the Perseid meteor shower on August 13.

(See Your Best Shots of the Perseid Meteor Shower)

Skywatchers on the Asian continent had a ringside seat to this year's cosmic fireworks show as the official peak of the Perseids occurred during the overnight hours after the moon had set.

Despite the light pollution from cities, suburban observers were able to count as many as 30 or 40 shooting stars per hour, while the dark countryside saw peak rates reach up to 130 meteors per hour.

Published August 23, 2013

Asteroid Flyby

Photograph courtesy NASA/JPL-Caltech  

A potentially hazardous asteroid—called 1998 KN3—is seen in this infrared image by NASA's WISE satellite gliding past a giant cloud of gas and dust near the famous Orion nebula star factory.

Infrared light can help astronomers determine the physical properties of asteroids like size and surface reflectivity.

The glow of the 0.7-mile-wide (1.1-kilometer-wide) asteroid appears as the yellow-green dot toward the upper left of this image, indicating to astronomers that the space rock is about room temperature—cooler than the blue stars, but warmer than the red dust.

Published August 23, 2013

Colorful Curtains

Photograph by Karl Ander Adami, National Geographic Your Shot    

Like a cosmic curtain being pulled across the skies, a colorful display of northern lights is seen in this image taken from the dark countryside of Estonia.

Aurora borealis are caused by giant clouds of charged particles blasting off the surface of the sun and hitting Earth's magnetic field. The solar particles are funneled down through the polar regions and strike oxygen and nitrogen based molecules in the upper atmosphere, causing them to glow like neon signs.

Published August 23, 2013

Cosmic Bubble

Photograph by Terry Hancock, National Geographic Your Shot  

Like a cosmic bubble suspended among the stars, the Bubble Nebula is a giant cloud of gas and dust 11,000 light-years from Earth in the northern constellation of Cassiopeia.

High speed radiation blasting out from a hot, young star—45 times more massive than our own sun—has blown out this distinctive ten-light-year-wide bubble shaped cloud structure.

Published August 23, 2013

Cosmic Sentinel

Photograph by Keith Marsh, National Geographic Your Shot  

A centuries-old bristlecone pine seems to reach toward the starry sky and the ghostly glow of the Milky Way in this long exposure photograph taken in the White Mountains of California.

The central core of the Milky Way galaxy, more than 30,000 light-years from Earth, glows from the light of millions of stars at the center of the image.

Published August 23, 2013

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Image courtesy ESO  

Published August 23, 2013