This Week's "Where in the Universe?" Challenge

May 14th, 2008

This Week's "Where in the Universe?" Challenge

Here's your image for this week's "Where in the Universe?" challenge. Take a look at the image and before proceeding to the end of this post, make your guess as to what location in the universe is represented here. It could be anywhere — nothing is off limits for this challenge! Near or distant, far and wide, Universe Today spares no expense when it comes to searching for unique and unusual images to test your visual knowledge of our universe! Give yourself an extra point for guessing (or knowing) the feature shown here, and another point for naming the spacecraft that took this image. Just a couple more ticks on the timer here before revealing the awesome power of this week's image….

Have you made your guess?

Here's the answer:

These are cloud vortices found near Alaska, here on Earth. These are called von Karman cloud vortices, named after Theodore von Karman, co-founder of the Jet Propulsion Laboratory. These vortices near the Aleutian Islands were photographed by an Expedition 15 crewmember on the International Space Station. The vortices are created by the wind encountering a barrier such as an island, then changing direction and velocity and forming eddies in the wind and subsequently, in cloud patterns. The image was taken almost a year ago, on May 23, 2007 and the location of the image is at 51.1 degrees north latitude and 178.8 degrees west longitude.

In the cloud image above, the islands disturb the wind flow. As a prevailing wind encounters the island, the disturbance in the flow propagates downstream of the island in the form of a double row of vortices which alternate their direction of rotation. The animation below (courtesy of Cesareo de la Rosa Siqueira at the University of Sao Paulo, Brazil) shows how a von Karman vortex develops behind a cylinder moving through a fluid.