Actual asteroid impact with Earth's upper atmosphere

From NASA:

On October 8, 2009 about 03:00 Greenwich time, an atmospheric fireball blast was observed and recorded over an island region of Indonesia. The blast is thought to be due to the atmospheric entry of a small asteroid about 10 meters in diameter that, due to atmospheric pressure, detonated in the atmosphere with an energy of about 50 kilotons (the equivalent of 100,000 pounds of TNT explosives).

The blast was recorded visually and reported upon by local media representatives. See the YouTube video at:



neo.jpl.nasa.gov/news/news165.html

Seanie.

That's pretty amazing. circa 50 kilotons - the bomb on Hiroshima was only 15-18 kilotons! The article states that 50kT is equivalent to 110 million pounds of TNT (not sure were you read 100,000 pounds, Seanie).

The stated location is above land - I really would have thought that an airburst of that magnitude would have caused widespread reports of at least temporary blindness.

I realise that it's suggested that its a stratosphere event but I'm suprised that that did not have global reporting closer to the time. Maybe area is not well populated.

If it weren't on a NASA site I'd have dismissed this without much further ado. And even then a little bit of sceptism still remains.

Mark

FYI

Wall of secrecy - Why wasn't this asteroid observed before it hit?

SwRI's Chapman said he was not aware that the object was seen before it plowed into Earth's atmosphere.

"The body was large enough that some of the current Spaceguard Survey telescopes might have detected it a couple of days before it hit, were it coming from the night sky. But it struck during daytime and probably could not have been seen by those telescopes," Chapman explained. A second question is whether it was detected by military satellites that monitor bright flashes in the Earth's atmosphere for defense and security purposes.

"Almost certainly it was detected and presumably immediately identified as an explosion of a large meteoroid rather than, say, an explosion of a human-made device in the atmosphere," Chapman figures. "But these satellites are secret and, in the past, the establishments controlling them have delayed releasing the data, for weeks or months."

Earlier this year, Chapman added, a change in previous policy led the U.S. military to withhold the data from the public.

"Scientists hope that they will reverse that policy. This event will demonstrate whether the wall of secrecy is coming down again, or not," Chapman noted. "Evidently, because of the passage of weeks since the event, there has been no decision to release the data promptly."

mjc wrote:

The article states that 50kT is equivalent to 110 million pounds of TNT (not sure were you read 100,000 pounds, Seanie).

I just copied that part from the NASA article Mark! I didn't digest the figures when I read it.

And I haven't done any sanity check arithmetic - I don't know how many lbs equates to 1 kiloton - but the magnitude was large (in my mind) as reported.

I have a vague memory - going back to the 1980's - when the cold war was at its height. I remember reading that a 1 megaton airborne nuclear detonation over Birmingham would cause temporay blindness of an observer who saw the event from the closest periphery of London.

Okay this is 50kT compared with 1 megaton(ne) - still sounds quite large - I'm really suprised that there wasn't more news coverage.

Impact on Jupiter (big) then us (relativity small) - scary universe...

Mark