* Astronomy

Half-Century Old Moon Mystery Solved

 

In the early morning hours of Nov. 15, 1953, an amateur astronomer in Oklahoma photographed what he believed to be a massive, white-hot fireball of vaporised rock rising from the center of the Moon's face. If his theory was right, Dr. Leon Stuart would be the first and only human in history to witness and document the impact of an asteroid-sized body impacting the Moon's scarred exterior.
Almost a half-century, numerous space probes and six manned lunar landings later, what had become known in astronomy circles as "Stuart's Event" was still an unproven, controversial theory. Skeptics dismissed Stuart's data as inconclusive and claimed the flash was a result of a meteorite entering Earth's atmosphere. That is, until Dr. Bonnie J. Buratti, a scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Lane Johnson of Pomona College, Claremont, California, took a fresh look at the 50-year-old lunar mystery.

"Stuart's remarkable photograph of the collision gave us an excellent starting point in our search. We were able to estimate the energy produced by the collision. But we calculated that any crater resulting from the collision would have been too small to be seen by even the best Earth-based telescopes, so we looked elsewhere for proof" - Dr. Bonnie J. Buratti.

Buratti and Lane's reconnaissance of the 35-kilometre wide region where the impact likely occurred led them to observations made by spacecraft orbiting the Moon. First, they dusted off photographs taken from the Lunar Orbiter spacecraft back in 1967, but none of the craters appeared a likely candidate. Then they consulted the more detailed imagery taken from the Clementine spacecraft in 1994.

"Using Stuart's photograph of the lunar flash, we estimated the object that hit the Moon was approximately 20 metres across, and the resulting crater would be in the range of one to two kilometres across. We were looking for fresh craters with a non-eroded appearance" - Dr. Bonnie J. Buratti.

Part of what makes a Moon crater look "fresh" is the appearance of a bluish tinge to the surface. This bluish tinge indicates lunar soil that is relatively untouched by a process called "space weathering," which reddens the soil. Another indicator of a fresh crater is that it reflects distinctly more light than the surrounding area.
Buratti and Lane's search of images from the Clementine mission revealed a 1.5-kilometre wide crater. It had a bright blue, fresh-appearing layer of material surrounding the impact site, and it was located in the middle of Stuart's photograph of the 1953 flash. The crater's size is consistent with the energy produced by the observed flash; it has the right colour and reflectance, and it is the right shape.
Having the vital statistics of Stuart's crater, Buratti and Lane estimated that the energy released in the impact would have been the equivalent of half a Megaton of TNT, (35 times more powerful than the Hiroshima atomic bomb)
If it had struck the Earth, such an impact would have caused the destruction of a large metropolitan-sized area.

"To me this is the celestial equivalent of observing a once-in-a-century hurricane. We're taught the Moon is geologically dead, but this proves that it is not. Here we can actually see weather on the Moon" - Dr. Bonnie J. Buratti.

While Dr. Stuart passed on in 1969, his son Jerry Stuart offered some thoughts about Buratti and Lane's findings.

"Astronomy is all about investigation and discovery. It was my father's passion, and I know he would be quite pleased".If Buratti is right, such impacts may be more frequent than thought - about once every 30 years on the Earth, and every 500 years on the Moon. But other asteroid watchers think the flash was due to a small meteor burning up in Earth's atmosphere. 

What is the chance of the Earth being hit , 100% !

For U.S. residents, here the odds of dying in certain select ways:

Car Crash:	1-in-100
Electrocution:	1-in-5,000
Asteroid Impact:	1-in-20,000
Plane Crash:	1-in-20,000
Tornado:	1-in-60,000
Bite or Sting:	1-in-100,000

The overall effects of an asteroid 1 kilometre wide or bigger could wipe out crops and bring human civilization to its knees.

In 1178, Gervase of Canterbury reported seeing a bright flash on the Moon and some researchers believe that a crater called Bruno on the far side was the result, but doubt has been cast on this claim.

In 1908, a relatively small object flattened 2,000 square kilometres of Siberian forest at Tunguska, and a near-miss was reported as recently as June last year.
In 2000 Atlanta 200 tonne asteroid, 1 megaton explosion
In 2001 pacific 10 mega tonne explosion
In 2002 Mediterranean near miss

Currently '1950 da' is the most dangerous rock in space, that we know about. It is a 1 km 100,000 megaton bomb. It spins quickly and is a solid rock; and it may possibly hit the Earth on March 16, 2880.