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With the help of a self-developed computer model, a team of researchers forecasted how apatite would have crystalized from cooling bodies of lunar magma early in the Moon's history. The model proved that the abnormally hydrogen-rich apatite crystals seen in many Moon rock samples may not have developed within a water-rich environment as previously though. "The mineral apatite is the most widely used method for estimating the amount of water in lunar rocks, but it cannot be trusted," said Jeremy Boyce of the UCLA Department of Earth, Planetary and Space Sciences in a statement. "Our new results show that there...

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...

New Haven, Conn. — The Gondwana supercontinent underwent a 60-degree rotation across Earth’s surface during the Early Cambrian period, according to new evidence uncovered by a team of Yale University geologists. Gondwana made up the southern half of Pangaea, the giant supercontinent that constituted the Earth’s landmass before it broke up into the separate continents we see today. The study, which appears in the August issue of the journal Geology, has implications for the environmental conditions that existed at a crucial period in Earth’s evolutionary history called the Cambrian explosion, when most of the major groups of complex animals rapidly...

Skywatchers have been trying to gauge the sun-Earth distance for thousands of years. In the third century BC, Aristarchus of Samos, notable as the first to argue for a heliocentric solar system, estimated the sun to be 20 times farther away than the moon. It wasn't his best work, as the real factor is more like 400. By the late 20th century, astronomers had a much better grip on this fundamental cosmic metric -- what came to be called the astronomical unit. In fact, thanks to radar beams pinging off various solar-system bodies and to tracking of interplanetary spacecraft, the...

University of Arizona scientists have uncovered a curious case of missing asteroids. The main asteroid belt is a zone containing millions of rocky objects between the orbits of Mars and Jupiter. The scientists find that there ought to be more asteroids there than researchers observe. The missing asteroids may be evidence of an event that took place about 4 billion years ago, when the solar system's giant planets migrated to their present locations. UA planetary sciences graduate student David A. Minton and UA planetary sciences professor Renu Malhotra say missing asteroids is an important piece of evidence to support an...

BOSTON—The number of Earth-like extrasolar planets suitable for harboring advanced life could be 10 times higher than has been assumed until now, according to a new modeling study. The finding contradicts the prevailing notion that a terrestrial planet needs a large moon to stabilize the orientation of its axis and, hence, its climate. In 1993, French mathematicians Jacques Laskar and Philippe Robutel showed that Earth’s large moon has a stabilizing effect on our planet’s climate. Without the moon, gravitational perturbations from other planets, notably nearby Venus and massive Jupiter, would greatly disturb Earth’s axial tilt, with vast consequences for the...

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...

Line up Mercury, Venus, Earth and Mars according to their distance from the sun and you'll see their size distribution is close to symmetrical, with the two largest planets between the two smallest. That would be no coincidence -- if the pattern emerged from a debris ring around the sun. Brad Hansen of the University of California, Los Angeles, built a numerical simulation to explore how a ring of rocky material in the early solar system could have evolved into the planets. He found that two larger planets typically form near the inner and outer edges of the ring, corresponding...

Neptune's largest moon, Triton, was originally a member of a duo orbiting the Sun but was kidnapped during a close encounter with Neptune, a new model suggests. Triton is unique among large moons in that it orbits Neptune in a direction opposite to the planet's rotation, which long ago led scientists to speculate that the moon originally orbited the Sun. But until now, no convincing theory for how Triton paired with Neptune existed. Gravity might have pulled Triton away from its companion to make it an orbiting satellite of Neptune, researchers report in a new study published in the May...

This high tide is bound to wash away more than just your sand castle. A new study has found that bulges in Earth's crust — solid Earth tides — trigger about 1 percent of earthquakes. As Earth and the moon grind through their gravitational ballet, our planet gets tugged hard near the equator. The force is so strong that as the moon passes overhead each day, it pulls Earth's surface up 11.8 inches.

Without the Moon, there would have been no life on Earth. Four billion years ago, when life began, the Moon orbited much closer to us than it does now, causing massive tides to ebb and flow every few hours. These tides caused dramatic fluctuations in salinity around coastlines which could have driven the evolution of early DNA-like biomolecules. This hypothesis, which is the work of Richard Lathe, a molecular biologist at Pieta Research in Edinburgh, UK, also suggests that life could not have begun on Mars. According to one theory for the origin of life, self-replicating molecules such as DNA...

Asteroid Vesta: The 10th Planet? Discovery Brightens Odds of Finding Another Pluto Nemesis: The Million Dollar Question HOUSTON, TEXAS -- Our solar system may have had a fifth terrestrial planet, one that was swallowed up by the Sun. But before it was destroyed, the now missing-in-action world made a mess of things. Space scientists John Chambers and Jack Lissauer of NASA's Ames Research Center hypothesize that along with Mercury, Venus, Earth, and Mars -- the terrestrial, rocky planets -- there was a fifth terrestrial world, likely just outside of Mars's orbit and before the inner asteroid belt. Moreover, Planet V...

December 23, 2005: NASA scientists have observed an explosion on the moon. The blast, equal in energy to about 70 kg of TNT, occurred near the edge of Mare Imbrium (the Sea of Rains) on Nov. 7, 2005, when a 12-centimeter-wide meteoroid slammed into the ground traveling 27 km/s. "What a surprise," says Marshall Space Flight Center (MSFC) researcher Rob Suggs, who recorded the impact's flash. He and colleague Wes Swift were testing a new telescope and video camera they assembled to monitor the moon for meteor strikes. On their first night out, "we caught one," says Suggs.

The moon formed after a nasty planetary collision with young Earth, yet it looks odd next to its watery orbital neighbor. Turns out it really is odd: Only about one in every 10 to 20 solar systems may harbor a similar moon. New observations made by NASA's Spitzer Space Telescope of stellar dust clouds suggest that moons like Earth's are—at most—in only 5 to 10 percent of planetary systems. "When a moon forms from a violent collision, dust should be blasted everywhere," said Nadya Gorlova, an astronomer at the University of Florida in Gainesville who analyzed the telescope data in...

Moons like the Earth's - which are formed in catastrophic collisions - are extremely rare in the Universe, a study by US astronomers suggests. The Moon was created when an object as big as the planet Mars smacked into the Earth billions of years ago. The impact hurled debris into orbit, some of which eventually consolidated to form our Moon. The Astrophysical Journal reports that just 5-10% of planetary systems in the Universe have moons created this way.

Moon is younger and more Earth-like than thought 20:13 19 December 2007 NewScientist.com news service Maggie McKee It's a good thing the Moon doesn't have any feelings to hurt. New research suggests it is actually 30 million years younger than anyone had thought, and that it is merely a 'chip off the old block' of Earth rather than being made up of the remnants of a Mars-sized body that slammed into Earth billions of years ago. That violent impact was thought to have taken place 30 million years after the solar system began to condense from a disc of gas...

Speranza points out another difficulty with the impact-origins theory. Large blocks of limestone sit within the boundaries of the Sirente "crater." Such limestone would not have survived an impact. So if Ormö's theory is correct, one must surmise that somebody set these giant chunks of rock in place since the crater formed. To Speranza, that just didn't make sense. Speranza and colleagues further argue that Ormö's radiocarbon dating gave one age for the main feature (placing it in the 4th or 5th century a.d.) and a completely different age for a nearby "crater" called C9, a date in the 3rd...

The far side of the moon could have been visible from earth billions of years ago, a new study suggests.The relative rotations of the moon and the earth mean that only the one side is ever visible. However, scientists believe that the impact of a large asteroid hitting the moon could have flipped it around, turning a different side that we now see towards earth. A study of craters on the far side of the moon suggests that it was hit by a large object around 3.9 billion years ago.