If you might be outdoors performing some stargazing within the Western Hemisphere this night and are wanting up at simply the suitable time, you may catch sight of one thing that can seem fairly unusual: a small round cloud of sunshine that can quickly broaden to roughly the obvious measurement of a full moon, earlier than lastly fading away some minutes later.
What you’ll have simply seen isn’t some unusual atmospheric phenomenon, however a gas dump from a U.S. Space Force (USSF) mission that launched earlier today on a United Launch Alliance (ULA) Atlas V 511 rocket from Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida.
The launch, which occurred on proper on schedule at 2 p.m. EST (1900 GMT), carried two satellites for the us’s Space Systems Command (SSC). The mission, referred to as USSF 8, will place the 2 similar Geosynchronous Space Situational Awareness Program (GSSAP) satellites — GSSAP 5 and GSSAP 6 —on to a near-geosynchronous orbit roughly 22,300 miles (36,000 kilometers) above the equator.
Related: Atlas V rocket launches 2 surveillance satellites for US Space Force
According to ULA’s flight profile, 6 hours and 35 minutes after launch, the primary of the 2 satellites (GSSAP 5) can be launched to its geosynchronous orbit, adopted 10 minutes later by the second satellite (GSSAP 6).
Fuel dump ought to create luminous cloud
Seven hours, 11 minutes and 40 seconds after the launch, the Centaur second stage will dump its unused (extra) gas out into space. Dumping extra gas is the standard apply for all Centaur booster-assisted launches. It occurs after satellite separation; the gas bleeding off from a Centaur higher rocket stage.
As it seems, the timing of this occasion can be excellent for making a sky present for a lot of the Western Hemisphere. When the Centaur releases its extra gas, it is going to be nighttime over North and South America. But the Centaur, at an altitude of roughly 22,300 miles (36,000 km) can be in daylight and as such the gas can be reflecting daylight as seen from Earth.
In a Twitter thread, assiduous satellite watcher Cees Bassa has supplied a substantial quantity of data in regards to the visibility of the gas dump:
Alerting observers and astrophotographers! Friday night a gas dump from a rocket could also be seen as a brilliant nebula within the sky for observers in North, Central and South America. The gas dump will happen at 18:11PST/21:11EST for the deliberate 19:00UTC launch of the #AtlasV rocket. pic.twitter.com/EjO88ktAc8January 21, 2022
Bassa likens the looks of the gas dump as a “bright nebula, possibly as big as the full moon on the sky.”
“The cloud should be visible to the naked eye, and with binoculars or telescopes it should be possible to see the cloud grow and change shape,” Bassa added.
The gas dump is predicted for 9:11:40 p.m. EST (6:11:40 p.m. PST). It ought to out of the blue seem to the bare eye as an increasing round, comet-like cloud about 10 to fifteen levels west (or to the suitable) of the intense bluish zero-magnitude star Rigel within the Orion constellation. Your clenched fist held at arm’s size measures roughly 10 levels, so roughly “one or one and a half fists” to the suitable of Rigel is the place the cloud ought to seem.
Such gas dumps from satellites have been seen earlier than. On the night of Aug. 12, 1986, shortly after 10 p.m. EDT (0200 Aug. 13 GMT), numerous numbers of individuals throughout the U.S. and Canada, who have been watching the Perseid meteor bathe, have been shocked by a gas dump from a Japanese satellite launch that created a luminous cloud.
And on Sept. 1, 2004, the gas dump from an NRO-1 satellite launched earlier that day, was seen from the Eastern U.S. and Canada.
Why dump gas into space?
Some may ask what’s the necessity to dump gas into space? The motive it’s performed is for security; to reduce the danger of an explosion of the automobile, which in flip, would create a considerable amount of space junk, or orbital particles that might then put different space autos at at risk. At such a excessive altitude, the gas is dissipated shortly and poses no environmental risk to the Earth.
Joe Rao serves as an teacher and visitor lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers’ Almanac and different publications. Follow us on Twitter @Spacedotcom and on Facebook.
