Jupiter Fireball
© Hueso/Wesley/Go/Tachikawa/Aoki/Ichimaru/Petersen
The first of these collisions was observed by A. Wesley from Australia and C. Go from Philippines on June, 3 2010. The second object was observed by three Japanese amateur observers (M. Tachikawa, K. Aoki and M. Ichimaru) on August, 20 that year and a third collision was observed by G. Hall from USA on September, 10 2012 after a report of a visual observation from D. Petersen from USA.
Amateur astronomers observing Jupiter with video cameras for the past three years have observed a trio of collisions between small stellar objects occurring around the planet, according to research presented last week at the European Planetary Science Congress (EPSC 2013) in London.

The collisions are similar but smaller in scale than the meteor explosion that occurred over Chelyabinsk, Russia in February, explained Ricardo Hueso of the University of the Basque Country in Spain. Hueso presented a detailed report of these collisions during EPSC 2013, which concluded on Friday.

Such collisions are not uncommon in the Solar System, the researchers explained. Most smaller objects such as asteroids and comets have stable orbits, but some of them travel in orbits that place them at risk of colliding with planets. The smaller the objects, the more numerous they are and the more likely they are to cause collisions.

Comment: Not necessarily. The obvious reason that no one seems to want to spell out is that more material - big and small, 'stable' and 'unstable' - has entered the inner solar system. When it comes down to it, what everyone on this planet is about to learn is that there is no such thing as 'stability' in space!

The meteor responsible for the incident in Russia earlier this year was larger than most such objects, and as such collisions like the one it caused are rare. However, given that Jupiter is a larger planet with greater gravitational attraction, it typically gets hit far more often than Earth - and the collisions occur at much faster speeds.

Comment: Sure, but how on Earth (pun intended) can they claim that what they're seeing impact Jupiter is smaller than what hit Russia in February this year?!

If anything, given Jupiter's larger mass, those objects are going to be far larger.

In fact, Hueso and his colleagues report that their analysis shows that Jupiter could be hit by objects approximately 32 feet in size between 12 and 60 times each year, or approximately 100 times more than our home planet. Furthermore, those collisions occur at speeds of at least 37 miles per second, the astronomers added.

The research, which involved professional scientists assisting the amateur astronomers, also featured detailed simulations of objects entering Jupiter's atmosphere, where they disintegrated at temperatures topping 18,000 degrees Fahrenheit. The study also included observations of impact regions taken just tens of hours post-impact using instruments such as the Hubble Space Telescope or the Very Large Telescope (VLT).

"Despite observing the planet soon after the impact, Hubble and the VLT saw no signature of the disintegrated objects, showing that such impacts are very brief events," the researchers said in a statement. They noted that observatories like the Hubble and the VLT "cannot reliably observe" these impacts because their glow is "short-lived" and the collisions typically occur at "unpredictable" times.

These instruments "have packed observing schedules and cannot be dedicated to long-term monitoring of a planet," the astronomers added. "Amateur astronomers, who can dedicate night after night to observing a planet, have a far better chance of spotting these impacts, even if their equipment is far more rudimentary."

The first of the three collisions was observed on June 3, 2010 by Australian astronomer A. Wesley and C. Go from the Philippines. The second impact was witnessed by a trio of Japanese astronomers - M. Tachikawa, K. Aoki and M. Ichimaru - on August 20 of that year. American G. Hall observed the third collision on September 10, 2012 following a report of a visual observation from D. Petersen, who is also from the US.