If we ever get around to moving through the cosmos like something out of "Star Trek," we're going to want to watch out for more than just errant asteroids and comets. As NASA recently discovered, plasma cannonballs flying at 500,000 miles per hour could also pose a potential threat.
The space agency recently revealed that the Hubble Telescope had detected massive blobs of super-hot gas, each more than twice the size of Mars, traveling at exceptional speeds away from a dying star. This deep space cannon fire, located more than 1,200 light years away, lies in the vicinity of a red giant named V Hydrae. The researchers studying the phenomenon say the plasma cannonballs are ejected roughly once every 8.5 years, a puzzling timeline that may have something to do with the orbit of a neighboring companion star.
"According to this theory, the companion would have to be in an elliptical orbit that carries it close to the red giant's puffed-up atmosphere every 8.5 years," the researchers said in a press release. "As the companion enters the bloated star's outer atmosphere, it gobbles up material. This material then settles into a disk around the companion, and serves as the launching pad for blobs of plasma, which travel at roughly a half-million miles per hour."
According to the researchers, it would take these plasma cannonballs only 30 minutes to travel the distance between Earth and the moon.
A team led by Raghvendra Sahai of NASA's Jet Propulsion Laboratory used Hubble's Imaging Spectrograph (STIS) to conduct observations of V Hydrae over an 11-year period. Not only were they able to witness the early stages of the plasma cannon fire, but they also recorded instances of ejected "cannonballs," each almost twice as hot as the surface of the sun, more than 37 billion miles away from their source. They estimate that the V Hydrae region has likely been firing plasma artillery into interstellar space for at least 400 years.
While they're uncertain over how long this process will continue, the current theory is that, eventually, the companion star will be engulfed by the dying red giant.
"This accretion disk engine is very stable because it has been able to launch these structures for hundreds of years without falling apart," Sahai said. "In many of these systems, the gravitational attraction can cause the companion to actually spiral into the core of the red giant star. Eventually, though, the orbit of V Hydrae's companion will continue to decay because it is losing energy in this frictional interaction. However, we do not know the ultimate fate of this companion."