London, Feb 2 (ANI): Critics have rejected the theory put forward by some scientists that the Moon may have been formed because of a massive nuclear explosion that occurred at the edge of Earth's core.
Rob de Meijer of the University of the Western Cape in South Africa and Wim van Westrenem of VU University Amsterdam are of the opinion that a massive nuclear explosion occurred at the edge of Earth's core, flinging red-hot, liquid rock into space.The orbiting detritus gradually congealed into what is now our planet's lone satellite - the Moon.
Marvin Herndon, an independent geophysicist based in San Diego, previously put forward the controversial hypothesis that uranium, the heaviest naturally occurring element, has sunk to the Earth's core and formed a "georeactor" several kilometres across.
According to a report in New Scientist, even he points out that such a reactor could not exist at the core-mantle boundary.
That's because uranium is so heavy that when it liquefies in a nuclear reaction, it should fall to the Earth's core.
"Meijer and Westrenem fail to realise that such a georeactor would melt itself down to the centre," said Herndon.
Others question the idea that heat from a runaway reactor would propel matter out of the Earth as proposed, since modelling this kind of explosion is far from trivial.
"How do they really know it would produce a thin jet of matter?" said astrophysicist Richard Gott of Princeton University.
Planetary physicist David Stevenson of Caltech is also skeptical.
"The whole idea is not physically sensible. Life is too short to spend on things like this," he said.
If the georeactor hypothesis is right, Gott questions why Venus did not form a moon in the same process, since Venus boasts a similar mass and composition to the Earth.
But the biggest hole in the idea is not that it is unnecessarily complicated, but that it is simply unnecessary.
In the standard "big splash" picture of the moon's origin, the infant Earth was struck by a Mars-mass impactor, dubbed Theia.
Some of the impactor, along with the Earth's mantle, formed a ring around the Earth that eventually congealed into the moon.
The main reason Meijer and van Westrenem concocted their scenario was to explain why the composition of the moon and the Earth's mantle are identical when the moon should have been contaminated by material from the impactor.
"The simple answer is that the impactor formed from material at the same distance from the sun as the Earth, and therefore had the same composition," said Gott. (ANI)