For the first time in recorded history a very small asteroid has been discovered before burning up in Earth’s atmosphere as a brilliant fireball. During the night of Oct 5/6, Rich Kowalski of the Mount Lemmon Survey discovered a new Near-Earth asteroid named 2008 TC3. It now appears that this object will hit the atmosphere of the Earth tonight (Oct 7 UT) at 2:46 UT (10:46 EDT) over northern Sudan in northeast Africa.
Based on the brightness of this asteroid, it is very small and probably on the order of 2-meters or 7-feet in diameter. As big as this may seem, objects this small usually break up into much smaller pieces with little remaining to hit the ground. If pieces do survive to hit the ground they will probably be small, no bigger than a grapefruit. What this object will do is produce a spectacular fireball for a few tens of seconds over the Sudan. The Near-Earth Object Project Office at NASA-JPL estimates that an event of this size occurs once every few months somewhere in the world. The fireball will probably be more spectacular than the Sept 19 fireball observed over southern California but will only be visible within a few hundred miles of northern Sudan. It will not be visible from the rest of the world.
This is the first time a small fireball producing asteroid has been observed before entering the Earth’s asteroid. Why hasn’t this happened before? Object of this size are very faint. In fact, of the 360000+ known asteroids, we have only found 2 other asteroids that are this small. Also asteroids very close to Earth move very fast. Now moving fast isn’t the problem, the problem is that there is so much junk in orbit around the Earth from decades of satellite launches, that it is very hard to tell the difference between a small close asteroid and an old satellite. So the current asteroid hunting telescopes have to be lucky to pick one of these objects up. In the future, the next generation of asteroid survey telescopes will be able to discover these objects further out. There may come a time in the not too distant future, when a spectacular fireball will be predicted to occur over a major population center days in advance. When that day happens, you won’t have to be lucky to see a fireball, you can just go outside at the predicted time and enjoy the show.
Before it hit the Earth’s atmosphere, 2008 TC3 was on an orbit that took it as close to the Sun as 0.91 AU and as far from the Sun as 1.63 AU. It took 1.43 years to orbit the Sun.
If any photos of the fireball become available I will post link to them.
Links to a few publications about 2008 TC3…
The discovery announcement from the Minor Planet Center
Press release from the University of Arizona
Press release from the Near-Earth Object Project Office at NASA JPL