NATIONAL GEOGRAPHIC'S BEST SPACE PICTURES THIS WEEK LXXXV

Week’s Best Space Pictures: Mars' Ancient River System
By Jane J. Lee, National Geographic News, 6 November 2015.

Feed your need for heavenly views of the universe with our pick of the most awe-inspiring space pictures. This week, light travels for 8.5 billion years and we glimpse a changing Cancun from on high.

1. Mapping Change

Cancun, Mexico and the thriving city that's grown out of what was once a sleepy fishing town look much different when seen by a satellite instrument that watches for thermal generation and reflection. This picture shows surface temperature and elevation.

2. Traces

Clouds drifting over Heard Island in the South Indian Ocean curl into a trail of vortices in this picture taken Monday. When winds encounter an object like a land mass, they spin into eddies called von Karman vortices. The swirling patterns can show up in clouds.

3. Transition

Galaxy Mrk 820 glows in the centre of this Hubble image released Monday. The object is classified as a lenticular galaxy, with aspects of both elliptical and spiral galaxies. Their star-making activities have also slowed down.

4. Oozing

Alaska's Malaspina glacier - North America's largest example of a piedmont glacier - squeezes through a steep-sided valley into a flat, open area like cake batter into a baking pan.

5. Ancient Channels

The craters and channels in the bottom part of this image could be the remains of a river system on Mars. The bare, rocky patch in the middle shows evidence of what might have been a river delta.

6. A Glimpse Into The Past

Eight and a half billion years ago, light left a huge galaxy cluster called MOO J1142+1527 and made its way to NASA's Spitzer Space telescope. The red galaxies bunched in the middle of this image are the heart of that cluster.

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