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The paper, titled Distinct oxygen isotope compositions of the Earth and Moon, may challenge the current understanding of the formation of the Moon. Previous research led to scientists to develop the Giant Impact Hypothesis suggesting the Moon was formed from debris following a giant collision between early-Earth and a proto-planet named Theia. The Earth and Moon are geochemically similar. Samples returned from the Moon from the Apollo missions showed a near-identical composition in oxygen isotopes. Although the Giant Impact Hypothesis can nicely explain many of the geochemical similarities between Earth and Moon, the extreme similarity in oxygen isotopes has been...

There are a number of theories about where the moon came from. Our best guess is that it was formed when the Earth was hit by a large object known as Theia. The impact threw up huge amounts of debris into orbit, which eventually coalesced to form the moon. There’s a problem with this theory. The mathematical models show that most of the material that makes up the moon should come from Theia. But samples from the Apollo missions show that most of the material on the moon came from Earth. A paper out earlier this week in Nature Geoscience...

In recent decades the scientific consensus has been that the moon formed billions of years ago from debris cast off when a Mars-sized object dealt Earth a glancing blow. But a radical new theory holds that some long-ago giant collision actually disintegrated Earth, causing it to balloon out into a vast doughnut-shaped cloud of vaporized rock, which the scientists who developed the theory dubbed a “synestia." They say the moon subsequently formed within this cosmic maelstrom. In the long-accepted explanation of lunar formation, the collision between Earth and the Mars-sized object, known as Theia, ejected part of Earth's mantle —...

A new theory says Earth is made of two planets, rather than just one. Apparently, our planet is the result of a collision that helped map the course of both Earth as we know it and the moon. According to new research from the University of California, Earth and a hypothesized early planet called Theia collided, and the two planets fused together 4.5 billion years ago. That impact also formed our moon, Science Alert explains. The initial working theory was that the Earth and Theia only side-swiped each other, sending the moon into orbit and then flying away into space....

A tiny 4.4-billion-year-old crystal has been confirmed as the oldest fragment of Earth's crust. The zircon was found in sandstone in the Jack Hills region of Western Australia. Scientists dated the crystal by studying its uranium and lead atoms. The former decays into the latter very slowly over time and can be used like a clock. The finding has been reported in the journal Nature Geoscience. Its implication is that Earth had formed a solid crust much sooner after its formation 4.6 billion years ago than was previously thought, and very quickly following the great collision with a Mars-sized body...

It's a classic image from every youngster's science textbook: a cutaway image of Earth's interior. The brown crust is paper-thin; the warm mantle orange, the seething liquid of the outer core yellow, and at the center the core, a ball of solid, red-hot iron. Now a new theory aims to rewrite it all by proposing the seemingly impossible: Earth has not one but two inner cores. The idea stems from an ancient, cataclysmic collision that scientists believe occurred when a Mars-sized object hit Earth about 4.45 billion years ago. The young Earth was still so hot that it was mostly...

Russia is planning to study the moon intensively with the assistance of unmanned missions after a break of more than 30 years. It will launch the first missions out of four of the “Lunar-Resource” and the “Lunar-Sphere” missions by the end of 2012 and early 2013. They will carry out preparations for the creation of a permanent fully-robotic base on the moon. Such a base will be an essential element for the future manned missions to the moon. Here are more details from Boris Pavlishev. Japan, NASA, the European Space Agency, India and China have launched probes to moon since...

STEREO Hunts for Remains of an Ancient Planet near Earth April 9, 2009: NASA's twin STEREO probes are entering a mysterious region of space to look for remains of an ancient planet which once orbited the Sun not far from Earth. If they find anything, it could solve a major puzzle--the origin of the Moon. The name of the planet is Theia," says Mike Kaiser, STEREO project scientist at the Goddard Space Flight Center. "It's a hypothetical world. We've never actually seen it, but some researchers believe it existed 4.5 billion years ago—and that it collided with Earth to form...

Clara Moskowitz The solar system might once have had another planet named Theia, which may have helped create our own planet's moon. Now two spacecrafts are heading out to search for leftovers from this rumored sibling, which would have been destroyed when the solar system was still young. "It's a hypothetical world. We've never actually seen it, but some researchers believe it existed 4.5 billion years ago — and that it collided with Earth to form the moon," said Mike Kaiser, a NASA scientist at the Goddard Space Flight Center in Maryland...

April 9, 2009: NASA's twin STEREO probes are entering a mysterious region of space to look for remains of an ancient planet which once orbited the Sun not far from Earth. If they find anything, it could solve a major puzzle--the origin of the Moon. "The name of the planet is Theia," says Mike Kaiser, STEREO project scientist at the Goddard Space Flight Center. "It's a hypothetical world. We've never actually seen it, but some researchers believe it existed 4.5 billion years ago—and that it collided with Earth to form the Moon." Right: An artist's concept of one of the...

It is possible that such a phenomenon could occur when matter around a newborn star forms into planets. In a planet's orbit around a star, there are two places where a third body can safely orbit. These spots, known as Lagrange points, are 120 degrees in front of and behind whichever body is smaller. The discovered co-orbiting planets, located in the four-planet system KOI-730, are always 120 degrees apart, permanent fixtures in each others' night skies. Fifty million years after the birth of our solar system, the moon may have formed from the debris of a collision between Earth and...