Free Republic

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.

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...

Deep down, the moon may be more like Earth than scientists ever thought. A new moon-rock study suggests the satellite has an iron core... The moon's core could be a clue to its ancient origins, which have long puzzled astronomers. "Our moon is too big to be a moon," Taylor said. "It's huge compared to the moons we see around other planets, so it has always been suspected that there was something strange in its origin." ...Rock samples from NASA's Apollo 15 and Apollo 17 moon missions of the early 1970s have now shed more light on the moon's origins,...

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.

The crash may also someday create the biggest and brightest comet of all time. Astronomer Michael Brown of the California Institute of Technology found the five fragments while studying the Kuiper belt, located in the solar system's outermost reaches. The fragments resemble 2003 EL61, the Kuiper belt's mysterious third largest object, suggesting all six bodies were formed in a single violent crash, Brown said... Measuring about 930 miles (1,500 kilometers) across, 2003 EL61 had puzzled scientists ever since its discovery, because it's oblong and spins end-over-end so fast that it completes a full revolution every four hours... 2003 EL61 is...

An enormous impact basin located near the lunar south pole may have caused the Moon to roll over early in its history, new research suggests... Called the South Pole-Aitken (SPA) basin, it is 2500 kilometres wide and 12 kilometres deep and is thought to have been created about 4 billion years ago. Francis Nimmo of the University of California in Santa Cruz, US, believes the impact probably occurred near the Moon's equator. That is because the equator lies in the plane of most other objects in the solar system and therefore would more likely be in a hurtling space rock's...

Water found in ancient Moon rocks might have actually originated from the proto-Earth and even survived the Moon-forming event. Latest research into the amount of water within lunar rocks returned during the Apollo missions is being presented by Jessica Barnes at the European Planetary Science Congress in London on Monday 9th September. The Moon, including its interior, is believed to be much wetter than was envisaged during the Apollo era. The study by Barnes and colleagues at The Open University, UK, investigated the amount of water present in the mineral apatite, a calcium phosphate mineral found in samples of the...

New calculations that indicate how the Moon's surface and interior react to the gravitational pull of the Earth and the Sun have produced further evidence that molten "slush" exists beneath the lunar surface... The first evidence of a soft region near the Moon's core was found using seismological equipment placed at different places on the surface during the Apollo missions. These found that moonquakes lost their energy when they traveled further than 1,000 kilometers below the Moon's surface. Since 1977, when these measurements ended, there has been no further evidence.

Present-day nautilus shells almost invariably show thirty daily growth lines (give or take a couple) between the major partitions, or septa, in their shells. Paleontologists find fewer and fewer growth lines between septa in progressively older fossils. 420 million years ago, when the moon circled the earth once every nine days, the very first nautiloids show only nine growth lines between septa. The moon was closer to the earth and revolved about it faster, and the earth itself was rotating faster on its axis than it is now. The day had only twenty-one hours, and the moon loomed enormous in...

Early in the evening of June 18, 1178, a group of men near Canterbury, England, stood admiring the sliver of a new moon hanging low in the west. In terms they later described to a monk who recorded their sighting, "Suddenly a flaming torch sprang from the moon, spewing fire, hot coals and sparks." In continuing their description of the event, they reported that "The moon writhed like a wounded snake and finally took on a blackish appearance"... [P]lanetary scientist Jack Hartung of the State University of New York... gathered enough clues to suggest that a large asteroid... might have...

At 8.45 on the morning of 15 April 136 BC, Babylon was plunged into darkness when the Moon passed in front of the Sun. An astrologer, who recorded the details in cuneiform characters on a clay tablet, wrote: "At 24 degrees after sunrise-a solar eclipse. When it began on the southwest side, Venus, Mercury and the normal stars were visible. Jupiter and Mars, which were in their period of disappearance, became visible. The Sun threw off the shadow from southwest to northeast." If present-day astronomers use a computer to run the movements of the Earth, Moon and Sun backwards...

An analysis of sediments brought back by the Apollo 17 mission has shown that the Moon's interior holds far more water than previously thought.The analysis, reported in Science, has looked at pockets of volcanic material locked within tiny glass beads. It found 100 times more water in the beads than has been measured before, and suggests that the Moon once held a Caribbean Sea-sized volume of water. The find also casts doubt on aspects of theories of how the Moon first formed. A series of studies in recent years has only served to increase the amount of water thought to...

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...

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...