<p>This image of Arctic ice is a study in aging. Older, thicker ice contains fewer air pockets, giving the ice a light blue color. The gray ice is only a year old, and its thin structure lets some of the darker color of the seawater below show through.</p>

Black and Blue

This image of Arctic ice is a study in aging. Older, thicker ice contains fewer air pockets, giving the ice a light blue color. The gray ice is only a year old, and its thin structure lets some of the darker color of the seawater below show through.

Photograph by NASA Earth Observatory

Week's Best Space Pictures: Blue Ice and a Rocket Launch

Arctic ice changes color while volcanic gases swirl through the air in this week's best space pictures.

Arctic ice changes color while volcanic gases swirl through the air in this week's best space pictures.

DON'T MISS THE REST OF THIS STORY!
Create a free account to continue and get unlimited access to hundreds of Nat Geo articles, plus newsletters.

Create your free account to continue reading

No credit card required. Unlimited access to free content.
Or get a Premium Subscription to access the best of Nat Geo - just $19
SUBSCRIBE

Read This Next

'World’s worst shipwreck' was bloodier than we thought
World’s first ultrasounds of wild manta rays reveal a troubling truth
Titanic was found during secret Cold War Navy mission

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet