Massive, superhot blobs of gas are zooming through space in a mysterious phenomenon that has been in action for the past 400 years. What's going on?

According to a report from Phys Org, the balls of fire spotted by NASA's Hubble Space Telescope are estimated to be twice as big as the planet Mars and are plummeting through space at a speed that would take them from Earth to the moon in only 30 minutes. Each blob has a temperature of about 17,000 degrees Fahrenheit, making them almost as hot as the surface of the sun.

The phenomenon of shooting the fireballs occurs once every 8.5 years for the last 400 years.

The cannonballs are being ejected near a dying star called V Hydrae that's roughly 1,200 light-years away. Initial assumptions would point to the host star, but scientists say the blobs of gas could not have come from V Hydrae, which is a bloated red giant that has likely already dropped half of its mass in its death throes.

The best theory at the moment is the presence of an unseen companion star that initiates the launch of the plasma balls. This star would be in an elliptical orbit that brings it near V Hydrae's atmosphere every 8.5 years, when it would "gobble up" the material. This material would then adjust as a disk around the companion and become a launching pad for blobs of hot plasma speeding through space at around half a million miles per hour.

" This model provides the most plausible explanation because we know that the engines that produce jets are accretion disks," explained Raghvendra Sahai of NASA's Jet Propulsion Laboratory in Pasadena, California. Sahai developed the theoretical model with his colleagues. "Red giants don't have accretion disks, but many most likely have companion stars, which presumably have lower masses because they are evolving more slowly."

He added, "The model we propose can help explain the presence of bipolar planetary nebulae, the presence of knotty jet-like structures in many of these objects, and even multipolar planetary nebulae. We think this model has very wide applicability."

The study also appeared in the Astrophysical Journal, as shown in Hubble Site.