Fireballs show up in the night sky all over Earth on a regular basis. Depending on the size of the object creating them, they can range from a brief streak of light to huge explosions that send shockwaves for miles in all directions. Smaller ones are more common, of course, but the massive fireball that appeared over Australia in 2016 may have been even more special that astronomers first realized.
As ScienceAlert reports, observations of the fireball in 2016 revealed it to be on the larger side, producing a brilliant streak in the sky as the intense friction of entry into Earth’s atmosphere tore it apart. It’s now thought that the object may have been a rare example of a “minimoon.”
Most of the time, a meteor streaking through the sky just happened to be in the wrong place at the wrong time in its orbit around the Sun. Chunks of space rock end up on a collision course with Earth and, when they get too close, they die in a fiery blaze. Every once in awhile, one of those objects approaches Earth at the right angle and speed that it actually enters an orbit around our planet, cruising around Earth like a tiny neighbor.
In a new paper published in The Astrophysical Journal, researchers compiled all the observations of the 2016 Australian fireball with the help of the Desert Fireball Network, calculating the angle at which it impacted Earth’s atmosphere as well as its speed and other factors. The fact that the object was moving very slowly and the angle at which it fell to Earth strongly suggests it was in orbit around our planet for some time before its brilliant light show.
Going forward, the scientists say that new ground-based telescopes may offer us the opportunity to detect and observe similar minimoons for months or even years before they meet their destructive ends.