Just as rivers have tributaries that feed their flow, small glaciers can flow as tributaries into larger ones. This astronaut photo shows Siachen Glacier and four of its tributaries coming Keep reading
Tag: astronaut
Growing Downstream
This astronaut photo shows Madagascar’s largest estuary, as of 2024. On the right side, the Betsiboka River flows northwest (right to left, in the image). Less than 100 years ago, Keep reading
Lines of Ice Eddies
In February 2024, the North Atlantic’s sea ice reached its furthest extent of the season, limning the coastline with tens of kilometers of ice. These images — both capturing the Keep reading
Ice Without Gravity
Astronaut Don Pettit is back in space, and that means lots of awesome microgravity experiments. Here, he grew thin wafers of ice in microgravity in a -95 degree Celsius freezer. Keep reading
Langebaan Lagoon
Strands of green and brown mix in Langebaan Lagoon on the South African coast in this astronaut photograph. The shallow tidal estuary has a sandy floor and, since no river Keep reading
Field of Dunes
Barchan dunes collide in this astronaut image of Brazil’s southern coastline. Barchan (pronounced “bar-kahn”) dunes are crescent-shaped; their tips point downwind into their direction of travel. When many barchan dunes Keep reading
Complex Dunes
Sometimes landscapes have a beauty that’s hard to see from the ground. This astronaut’s photo shows a dune field in the sand seas of Saudi Arabia. Vast linear dunes line Keep reading
Wave Clouds From Space
An astronaut snapped this image of wave clouds formed around the Crozet Islands, which lie between South Africa and Antarctica. Clouds like these form when warm, moist air gets pushed Keep reading
Where Fresh and Salty Meet
Waterways twist through the wetlands of Adair Bay in this astronaut-captured image of northwestern Mexico. The estuary marks the transition between the Great Altar Desert and the Gulf of California. Keep reading
Free Contact Lines
How a simple drop of water sits on a surface is a strangely complicated question. The answer depends on the droplet’s size, its chemistry, the roughness of the surface, and Keep reading