Tonight's sunset might look rather unusual if you live on the East Coast of the United States. NASA will be launching a rocket from the Wallops Flight Facility in Virginia that will release payloads of barium and strontium into the atmosphere, turning parts of the night sky blue-green and others red.
NASA does this kind of experiment every so often in order to study the flows of ionized and neutral particles in the upper atmosphere. The agency uses luminescent chemicals like barium to better visualize and track clouds of these particles as they get moved around in the ionosphere by the Earth's magnetic field. (The launch has to be very carefully scheduled, because the chemicals need sunlight to become luminescent, but the observer needs to be watching a dark sky.) NASA is also notes that the amount of barium and strontium used in the test "is much smaller than that used in a typical July 4th fireworks display and poses no hazard to the community."
Luminescent chemicals help NASA study the ionosphere
The launch will also serve another purpose. The rocket being used is a Black Brant IX suborbital rocket, one that NASA hopes to eventually use to eject payloads like experiments or microsatellites into low orbit. This particular Black Brant rocket was built using some unconventional techniques and materials. Some of its parts were 3D-printed, and there are no welds in the body of the rocket cylinder, which was made possible by an entirely different fabrication process called "near net shaping." The hope is that these innovations could someday lower a rocket's mass and, in turn, its cost.
The rocket is scheduled to launch between 7:00PM and 9:00PM ET, and the chemical payloads will be released about six minutes after liftoff. NASA says that it should be visible as far as 235 miles north of the launch site (New York City and Long Island), 232 miles south of it (near Morehead City, North Carolina), and 165 miles west (Charlottesville, Virginia). That all depends on the weather conditions, though. If you're having trouble seeing it, or live outside that area, NASA will also be streaming the event, which we will embed above when it goes live.