NASA Rocket to Create Clouds Tuesday
By Clara Moskowitz- Live Science
14 September 2009
A rocket experiment set to launch Tuesday aims to create artificial clouds at the outermost layers of Earth's atmosphere.
The project, called the Charged Aerosol Release Experiment (CARE), plans to trigger cloud formation around the rocket's exhaust particles. The clouds are intended to simulate naturally-occurring phenomena called noctilucent clouds, which are the highest clouds in the atmosphere.
"This is really essentially at the boundary of space," said Wayne Scales, a scientist at Virginia Tech who will use computer models to study the physics of the artificial dust cloud as it's released. "Nothing like this has been done before and that's why everybody's really excited about it."
The experiment is the first attempt to create artificial noctilucent clouds. A previous spacecraft, called Aeronomy of Ice in the Mesosphere (AIM), launched in 2007 to observe the natural clouds from space.
CARE is slated to launch Tuesday between 7:30 and 7:57 p.m. EDT (2330 and 2357 GMT) from NASA's Wallops Flight Facility in Virginia.
Noctilucent means "night shining" in Latin. Although difficult to spot with the naked eye, the clouds are best visible when Earth's surface is in darkness and sunlight from below the horizon illuminates the high-altitude clouds.
These clouds, also known as polar mesospheric clouds, are made of ice crystals. The natural ones tend to hover around 50 to 55 miles (80 to 90 km) above the Earth. CARE will release its dust particles a bit higher than that, then let them settle back down to a lower altitude.....
Noctilucent clouds over Mt.
Sabalan, a 15,784 ft extinct
volcano in northwestern Iran.
Credit: Siamak Sabet