Last night, off the coast of Virginia, NASA launched five small rockets in in five minutes to test the winds of the upper atmosphere. The rockets flew up to a height of about 100 km (60 miles) and released a chemical that was blown by those winds, forming an amazing, milky, ghostly scene:
The mission was called ATREX, for Anomalous Transport Rocket Experiment. The winds at this height above the Earth's surface aren't terribly well understood. This is far above where airplanes fly, but still well below the height of satellites. By releasing this (harmless) chemical and allowing the winds to blow it around, scientists could trace how these winds flow. Last night's launch took a while to get off the ground; there had been a few delays due to weather, and even holdups due to ships in the "red zone" in the Atlantic downrange from the launch site. The launches were visible for hundreds of kilometers up and down the coast. If you saw the launches and have pictures, NASA invites you to upload them to their Flickr group. NASA has a gallery of their own images from the launch online, and they're worth looking at. And this is a pretty interesting experiment. The height where these winds are located are where meteors burn up. Sometimes meteors burn up and leave a long tail of glowing debris that can stay lit for minutes. Called a persistent train, these can take on weird, twisted shapes as the winds blow them around. It's amazing to think we don't know that much about a part of the atmosphere not too far above our heads, and it makes me happy that scientists are -- as usual -- working hard to understand our planet better.