Monday April 21, 2003

Space Station Science

I've found another cool web site. This one is part of science.nasa.gov. The site I discovered today (with the assistance of a mailing-list friend ;-) is Space Station Science: Picture of the Day. You can subscribe to get the latest nifty info and picture in your mailbox, daily. I love the web.

Here's an excerpt from the entry for April 21, 2003:

The Physics of Space Gardens

Credit: ISS Expedition 6 Flight Engineer Nikolai Budarin

It could only happen in space: A tiny bubble of air hangs suspended inside a droplet of water. The droplet rests in the cup of a delicate green leaf, yet the stalk doesn't bend at all. Cosmonaut Nikolai Budarin photographed this scene on April 9, 2003. He was peering into the Russian Rasteniya greenhouse onboard the International Space Station (ISS), and his snapshot illustrates some of the strange physics of gardening in space .

First, consider what would happen on Earth: The air bubble, lighter than water, would race upward to burst through the surface of the droplet. Meanwhile, the leaf would be busy tipping the heavy water onto the floor below. Everything would be in motion, the picture a blur.

In Earth-orbit, though, the scene is truly motionless. The air bubble doesn't rise because it is no lighter than the water around it--there's no buoyancy. The droplet doesn't fall from the leaf because there's no force to pull it off. It's stuck there by molecular adhesion.

Be sure to read the rest of the story, with links and explore the archives. I recommend Blowing Bubbles too!

Space Station Science ( in category SciTech ) - posted at Mon, 21 Apr, 23:30 Pacific | «e»