NATIONAL GEOGRAPHIC'S BEST SPACE PICTURES THIS WEEK LII

Week's Best Space Pictures: Solar Storm and a Cosmic Iris
By Jane J. Lee, National Geographic News, 20 March 2015.

Auroras paint the night sky green for St. Patrick's Day and a thermonuclear explosion flings debris away from a star in this week's best space pictures.

1. Solar Storm

The most powerful solar storm to wash over Earth's magnetic field since fall 2013 slammed into us on Tuesday, producing auroras that lit up night skies around the world. These northern lights painted the heavens over Donnelly Creek, Alaska, a neon green.

2. Homecoming from Space

Russian personnel greet a Soyuz spacecraft ferrying a U.S. astronaut and two Russian cosmonauts on a return trip from the International Space Station. The crew members had spent six months orbiting Earth.

3. A Riot of Stars

Star clusters, emission nebulae, and stellar nurseries: This image of a section of the Ara OB1 stellar association has it all. The brightest spot in the middle is the open star cluster NGC 6193. Its light illuminates the Rim nebula (right).

4. Rough Terrain

This rough region of Mars is near the fictional Ares 3 landing site depicted in author Andy Weir's book The Martian. Weir describes the area as flat and smooth, but in reality, the terrain would be rough going for anyone driving over it.

5. Iris in the Sky

A thermonuclear explosion on the surface of a white dwarf star ejected gas and debris into space in the shape of an eye’s iris. Three telescopes caught this mini-supernova in action, with x-rays shown in blue, optical data in yellow, and radio waves in pink.

6. An Icy "Neck"?

Rosetta - the spacecraft that ferried the lander Philae to a somewhat shaky landing on a comet - beamed back an image of this celestial object's "neck." The bluish region connects the two halves of the comet, and could contain ice mixed with dust.

Photo gallery by Nicole Werbeck.

[Source: National Geographic News. Edited. Some links added.]