natural nuclear reactor

A natural nuclear reactor is therefore no longer possible on Earth without heavy water or graphite.

But not all experts are pessimistic about natural nuclear reactors on other worlds.

Natural nuclear reactors dating to 2 billion years ago have been found in Gabon, Africa.

Cullen said it's possible that natural nuclear reactors may have molded the genetic makeup of early life forms.

Boynton said he doubts that natural nuclear reactors like the ones in Gabon are common elsewhere.

The Oklo uranium ore deposits are the only known in which natural nuclear reactors existed.

The conditions under which a natural nuclear reactor could exist were predicted in 1956 by P. Kuroda.

Could natural nuclear reactors have boosted life?

If natural nuclear reactors might have helped life arise on this planet, it's also possible they've played a role in seeding life elsewhere.

They found that during the Archean epoch, between around 2.5 billion and 4 billion years ago, natural nuclear reactors could have been relatively frequent.

If the researchers are right, wherever there were oxygen-producing bacteria, there were also natural nuclear reactors.

So far, scientists' limited knowledge of the geology of extrasolar planets means they can't say how common natural nuclear reactors might be on other worlds.

The Oklo natural nuclear reactor of Gabon produced by uranium-precipitant bacteria.

The spark of life If natural nuclear reactors were present on early Earth, they could have had interesting effects on any nascent life.

Evidence for a cluster of natural nuclear reactors has been found on Earth, and some scientists say our planet may have had many more in its ancient past.

The concept of a natural nuclear reactor was theorized as early as 1956 by Paul Kuroda at the University of Arkansas.

One way to test that model might be to test ancient rocks for concentrations of lead that would indicate whether or not natural nuclear reactors were common in antiquity.

The natural nuclear reactors formed when a uranium-rich mineral deposit became inundated with groundwater that acted as a neutron moderator, and a strong chain reaction took place.

Only example The only known examples of natural nuclear reactors on Earth were discovered in the Oklo region of Gabon, Africa, in 1972.

Another factor which probably contributed to the start of the Oklo natural nuclear reactor at 2 billion years, rather than earlier, was the increasing oxygen content in the Earth's atmosphere.

At Oklo in Gabon, West Africa, about 2 billion years ago, at least 17 natural nuclear reactors commenced operation in a rich deposit of uranium ore.

Several uranium deposits at Oklo in the Republic of Gabon, a southwestern region of Africa, showed evidence of having operated as natural nuclear reactors for several hundred thousand years.

Other researchers have suggested that a strike of lightning might have provided the requisite energy, but Adam thinks that the energy released by a natural nuclear reactor might have provided the catalyst.

This work also lead to mass spectrometric investigations of the Oklo natural nuclear reactor to better understand the diffusion and retentivity of various fission products in the context of managing man-made nuclear waste.

Natural nuclear reactors occur when deposits of the radioactive element uranium build up in one spot, and eventually ignite a self-sustaining nuclear chain reaction where uranium divides, in a process called fission, producing other elements.