Did Aum Shinrikyo Test An A-Bomb?

Aum Shinrikyo now known as Aleph was a religion cult that started in Japan in 1984 by Shoko Asahara. The cult reached worldwide infamy in 1995 when it carried out the sarin gas attack in the Tokyo subways.

On May 28, 1993, a large seismic disturbance near the Banjawarn sheep station in West Victoria, Australia tripped earthquake sensors across the globe and registered 3.9 on the Richter scale. Witnesses saw a bright flash of light "like a far off explosion". It was later discovered that Aum owned a large plot of land near the epicenter. Some scientists and authorities believed this could have been a bomb test or even possibly an A-Bomb

Researchers in 1997 investigated and claimed it was a meteorite, but no crater was ever found. Although there is no mention of radioactive testing having been done either.

My question is, if a cult of what may have had as many as 40,000 members worldwide, had the ability to possibly build and test an A-Bomb in the Outback of Australia, then why is it out of the realm of possibility terrorist groups such as al-Qaida would not, especially given the financial backing and higher membership numbers?

[edit on 9-5-2010 by Ahabstar]

A nuclear explosion should have triggered automatics reactions by a number of nations around the world. Just the American response by an unexpected nuclear explosion would have been so massive that it could NOT have been hidden. The surveillance satellites would be unlikely to miss anything producing a flash noticed by people at a distance.

And oddly enough, nuclear weapons have been known to create craters. Conventional ones do too.

No crater, no kaboom.

If a terrorist organisation somehow comes into possesion of the materials and expertise required to make a nuclear bomb, they would test it on the intended target...