NATIONAL GEOGRAPHIC'S SPACE PICTURES THIS WEEK LXXII

Space Pictures This Week: Birth of a Star, Moon Lineup
By Andrew Fazekas, National Geographic News, 23 August 2013.

A violent star birth is caught on film and moons line up in this week's best space pictures.

1. Violent Star Birth

Kaleidoscope jets of super-fast gas mark the violent birth of a star 1400 light years from Earth.

Thanks to the high-resolution imaging capability of a new giant radio telescope array called the Atacama Large Millimetre/submillimetre Array (ALMA) in the high desert of Chile, astronomers have been able to reveal a large energetic jet moving away from us, seen in orange and green in the lower right of the above image. Meanwhile another jet, visible in pink and purple toward the left of the baby star, is beaming towards Earth.

The speeds at which the jets are spewing out material have been clocked at nearly a million kilometres (620,000 miles) an hour. The shockwave from these blasts plough into the gas and dust that surrounds the baby star - making them light up like neon signs.

2. Moon Roundup

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-(12 kilometres)-wide Deimos was12,800 miles (20,500 kilometres) in altitude, while 14-mile-(22 kilometres)-wide Phobos was much closer at only 3,900 miles (6,240 kilometres) from the rover.

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

3. Falling Stars

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 ring side 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.

4. Asteroid Flyby

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-(1.1 kilometres)-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.

5. Colourful Curtains

Like a cosmic curtain being pulled across the skies, a colourful 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 funnelled down through the polar regions and strike oxygen and nitrogen based molecules in the upper atmosphere, causing them to glow like neon signs.

6. Cosmic Bubble

Like a cosmic bauble 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 10-light-year-wide bubble shaped cloud structure.

7. Cosmic Sentinel

A centuries old Bristelcone 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 centre of the image.

[Source: National Geographic News. Edited.]