NATIONAL GEOGRAPHIC'S BEST SPACE PICTURES THIS WEEK XCI

Week's Best Space Pictures: Enceladus' Faces and Space Jets
By Michael Greshko, National Geographic News, 25 December 2015.

Feed your need for heavenly views of the universe. This week, NASA’s Cassini spacecraft bids farewell to Saturn’s moon Enceladus, a young star generates colourful shockwaves, and the dwarf planet Ceres gets its best-ever close-up.

1. Two-Face

NASA’s Cassini probe spies Saturn’s moon Enceladus during its final flyby of the icy moon. The shot lays bare Enceladus’ geological activity: the moon’s smooth surfaces (left) are much younger than its heavily cratered ones (right).

2. Shock and Awe

An extremely young star in the Orion Nebula (about 1,400 light-years away) shoots out hot jets of gas that collide into surrounding material, creating shockwaves that form Herbig-Haro objects such as the “beam” and wisps in the lower left.

3. Spines of Rock

NASA’s Terra satellite gazes upon the Urals - mountain ranges in western Russia that naturally divide Europe and Asia. Continental collisions formed the Urals 250 to 300 million years ago, making them some of Earth’s oldest mountains.

4. Cosmic Coattails

Galaxy CGCG254-021, the orange blob to the right, streams a massive gas tail aglow with X-rays (blue). The tail, some 250,000 light-years long, probably formed as the galaxy moved through gas clouds in the Zwicky 8338 galaxy cluster.

5. Twin Peaks

Bolshaya Ipelka (center) and Opala (lower left), volcanoes on eastern Russia’s Kamchatka Peninsula, loom over the landscape, as seen from the International Space Station. Over millions of years, glaciers carved Boshaya Ipelka’s furrows.

6. Get the Lowdown

NASA’s Dawn craft flies over Gerber Catena, a crater chain on Ceres, revealing a crustal groove that’s indicative of past geological stress. Dawn took the photo from 385 kilometres (240 miles) above Ceres’ surface, its closest and final orbit.

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