NATIONAL GEOGRAPHIC'S SPACE PICTURES THIS WEEK LXXX

Best Space Photos of the Week: Mars, Saturn, and Rune Stones
By Andrew Fazekas, National Geographic News, 18 October 2013.

NASA is back in business, delivering views of Mars, Saturn, and distant galaxies, plus northern lights among the rune stones.

1. Lord of the Rings

In a view possible only for a spacecraft flying above the plane of the solar system, this composite was created by Gordan Ugarkovic, an amateur astrophotographer who digitally stitched together 36 individual Cassini frames covering the gas giant and its majestic rings.

On close examination, a bizarre hexagon-shaped jet stream can be seen circling Saturn's northern pole, while the planet itself casts a long shadow onto its rings.

2. Frosty Fall

Autumn comes to Mars, and much like Earth, the landscape is nipped with frost.

This orbital image of the red planet's southern hemisphere was snapped by NASA's Mars Reconnaissance Orbiter on October 16. The sky-high view of the bottom of Richardson Crater shows a field of sand dunes covered with fall's first hint of carbon dioxide frost.

2. Colourful Pinwheel

A kaleidoscope of colours adorns the swirling centre of the nearby active galaxy called NGC 1433.

The dim blue spirals seen in the image are central dust lanes surrounding this galaxy 30 million light-years away, as viewed by the Hubble Space Telescope.

Near the galactic core, the coloured filamentous structures highlighted in the superimposed image come courtesy of the Atacama Large Millimetre/submillimetre Array (ALMA). ALMA's sharp new radio observations reveal a spiral shape, as well as unexpected jets of material spewing from a supermassive black hole at the centre of the galaxy.

This outflow of hot gas extends only 150 light-years, making it the smallest such structure ever observed outside of the Milky Way galaxy.

3. Green Flames

Photograph by Robert Novak, National Geographic Your Shot

The night sky above Andøya Island on Vesterålen, Norway, appears lit up by a gargantuan green flame on September 18.

Photographer Robert Novak snapped the northern lights show just as Earth's magnetic field was buffeted by charged particles blasting off from the surface of the sun.

As solar particles get funnelled into our planet's atmosphere around the poles, they collide with air molecules, causing them to glow like curtains of dancing light.

4. Runic Trails

Photograph by P-M Hedén, TWAN

Like a ritual dance around an ancient temple, star trails swirl around the North Star above Viking-era rune stones, in this long-exposure picture snapped in Vallentuna, Sweden.

Taken over many hours, the photo shows stars appearing to form trails around the north celestial pole, which is almost exactly aligned with the northern pole star, Polaris.

In the Southern Hemisphere, the south celestial pole is marked by a much fainter star called Sigma Octantis.

5. Cosmic Petals

Like delicate petals of a cosmic flower, an elliptical galaxy flaunts concentric shells of stars, gas, and dust in this image captured by the Hubble Space Telescope.

Located some 350 million light-years from Earth in the southern constellation Hydrus, the snake, PGC 6240 is believed to be the by-product of an ancient collision between two galaxies.

[Source: National Geographic News. Edited.]