This evening, if things go as planned, NASA will fill the sky with color soon after nine o’clock eastern time. The space agency will launch a Terrier-Improved Malemute sounding rocket from the Wallops Flight Facility on the Delmarva Peninsula that will deploy colorful vapor tracers. Skywatchers from New York to North Carolina may be able to catch a glimpse of the colorful tracer clouds lighting up the night sky in blue-green and red.
As Rhett Jones at Gizmodo reports, the rocket will release ten canisters, each about the size of a soda can, around five minutes after launch. This equates to an altitude between 96 and 124 miles above Earth. The canisters will release barium, strontium and cupric-oxide, forming colored clouds that researchers can visually monitor and track from the ground, which could help them understand the movements of particles in the ionsphere and aurora.
According to NASA, the mission, which is also a test of a new canister ejection system, was originally scheduled for May 31, but the experiment requires precise weather conditions, so it was scrubbed four times during the first week of June. A launch scheduled for yesterday was postponed because boats were present in the region where the 670-pound payload is expected to drop in the water.
While the heat wave that hit the East Coast over the weekend might not be great for barbecues, it is perfect for the rocket launch. “The area of high pressure responsible for the heat wave in the eastern U.S. will also promote clear skies through next week, which will bode well for the NASA launch,” says AccuWeather Meteorologist Faith Eherts.
This is by no means the first time NASA has lit up the night with vapor tracers. In fact, according to the agency, it has used sounding rockets to release vapor tracers in the upper atmosphere since the 1950s to understand the near-space environment.
But before you grab your tinfoil hat, know that the tracer experiments pose no dangers to life on the ground. According to NASA, the metals used are among those common in firework displays. But for the tracer experiments, the metals are released in much lesser amounts.
The sounding rocket program fills the gap between regions of the atmosphere that are too low for satellites to sample but too high for conventional aircraft to reach. While scientists do a lot of theoretical modeling of how particles in this region of the atmosphere move and interact, the vapor tracing allows them to check their assumptions.
The vapor tracers light up as they interact with ionized or neutral particles in the atmosphere, making the movements of these particles visible. Different types of tracers light up in the presence of diferent particles.
For instance, when barium, which is being used in tonight’s launch, is exposed to sunlight it ionizes rapidly and glows purple-red. Watching the dance of the barium clouds could provide information about how charged particles move in the ionosphere. But barium that is not ionized, which can be enhanced with the addition of strontium or lithium, can also be used to track neutral particles. Lithium alone can also be used to track neutral winds and can actually be used during daylight to track emissions, but glows a bright red at night.
For anyone interested in getting a glimpse of the colorful vapors, the What’s Up at Wallops? app provides updates on launch times and also includes a compass showing how to spot the dark rainbow. They are also posting launch updates to their twitter account and are streaming the launch live via Ustream.