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Boulder, Colo. — Nov. 10, 2011 — Just as an expert chess player sacrifices a piece to protect the queen, the solar system may have given up a giant planet and spared the Earth, according to an article recently published in The Astrophysical Journal Letters. "We have all sorts of clues about the early evolution of the solar system," says author Dr. David Nesvorny of the Southwest Research Institute. "They come from the analysis of the trans-Neptunian population of small bodies known as the Kuiper Belt, and from the lunar cratering record." These clues suggest that the orbits of giant...

The path of true love never runs smooth, it is said. Especially on Valentine's Day. And for young planets, that path turns out to be an inward-moving annulus. A simulation by scientists in France and USA appears to show that Jupiter once strayed to flirt with the inner Solar System, before being "jilted" and sent back to its present-day position. The effect of this was to form the inner planets, according to the theory, which comes up with mass ratios for Earth and Mars similar to that observed today and which, remarkably, also accurately depicts the Asteroid Belt. If 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...

Using the new Combined Array for Research in Millimeter Astronomy (CARMA), Eisner and his colleagues observed more than 250 stars in Orion's central region and found that less than 8% had dust disks thought massive enough to create a Jupiter. The radiation from hot, massive stars in the cluster probably clears out a lot of surrounding material and keeps high-mass disks from forming, explains co-author John Carpenter (Caltech). In all, about 10% of the observed stars emit radiation associated with warm dust disks. The results agree almost perfectly with findings by Geoff Marcy (UC Berkeley) and his colleagues, who conclude...

...planets are the most diverse and intricate class of object in the universe. No other celestial bodies support such a complex interplay of astronomical, geologic, and chemical and biological processes... The worlds of our solar system... hardly prepared us for the discoveries of the past decade, during which astronomers have found more than 200 planets. The sheer diversity of these bodies' masses, sizes, compositions and orbits challenges those of us trying to fathom their origins. When I was in graduate school in the 1970s, we tended to think of planet formation as a well-ordered, deterministic process -- an assembly line...

Jupiter increases risk of comet strike on Earth 11:53 24 August 2007 NewScientist.com news service David Shiga Earth experienced an especially heavy bombardment of asteroids and comets early in the solar system's history (Illustration: Julian Baum) Contrary to prevailing wisdom, Jupiter does not protect Earth from comet strikes. In fact, Earth would suffer fewer impacts without the influence of Jupiter's gravity, a new study says. It could have implications for determining which solar systems are most hospitable to life. A 1994 study showed that replacing Jupiter with a much smaller planet like Uranus or Neptune would lead to 1000 times...

This is an artist's concept of a hypothetical 10-million-year-old star system. The bright blur at the center is a star much like our sun. The other orb in the image is a gas-giant planet like Jupiter. Wisps of white throughout the image represent traces of gas. Astronomers using NASA's Spitzer Space Telescope have found evidence showing that gas-giant planets either form within the first 10 million years of a sun-like star's life, or not at all. The lifespan for sun-like stars is about 10 billion years. The scientists came to this conclusion after searching for traces of gas around...

In our Solar System, four planets stand out for their sheer mass and size. Jupiter, Saturn, Uranus and Neptune indeed qualify as "giant planets" because they are larger than any terrestrial planet and much more massive than all other objects in the Solar System, except the Sun, put together. According to Dr. Guillot, "the giant planets, because of their gravitational might, they have played a key role in the formation of the Solar System, tossing around many objects in the system, preventing the formation of a planet in what is now the asteroid belt, and directly leading to the formation...

For scientists who spend time thinking about how planets form, life would be simpler if gas giants like Jupiter and Saturn didn’t exist. According to the standard model of planet formation, called "core accretion," planets form over millions of years as enormous blocks of rock and ice smash together to form planetary embryos, called "protoplanets," and eventually full-fledged planets. Most scientists agree that core accretion is how terrestrial planets such as Earth and Mars were created, but the model can’t convincingly explain how gas giant planets like Jupiter and Saturn came to be. One major problem is that developing gas...

SPACE CENTER, Houston – NASA scientists have a new mystery to solve: How did materials formed by fire end up on the outermost reaches of the solar system, where temperatures are the coldest? The materials were contained in dust samples captured when the robotic Stardust spacecraft flew past the comet Wild 2 in 2004. A 100-pound capsule tied to a parachute returned the samples to Earth in January. The samples include minerals such as anorthite, which is made up of calcium, sodium, aluminum and silicate; and diopside, made of calcium magnesium and silicate. Such minerals only form in very high...

The Kuiper Belt, the region immediately beyond Neptune, harbors TNOs of many sizes. The largest is Pluto, which was discovered more than 60 years before any of the others. Some TNOs are "detached objects," which orbit so far from the sun that they're not appreciably affected by the gravity of Neptune or any other known planet. Perhaps the most famous of these is Sedna, which takes 11,400 years to make a single orbit and never comes closer to the sun than 20 times farther out than Pluto. In 2016, astronomers Konstantin Batygin and Mike Brown announced that a distant undiscovered...

More clues about where to search for a possible ninth planet lurking in the fringes of our solar system are emerging from the Kuiper belt, the icy debris field beyond Neptune. And new calculations suggest that the putative planet might be brighter — and a bit easier to find — than once thought. Evidence for the existence of Planet Nine is scant, based on apparent alignments among the orbits of the six most distant denizens of the Kuiper belt (SN: 2/20/16, p. 6). Their oval orbits all point in roughly the same direction and lie in about the same plane,...

There may be an alien planet lurking within Earth's own solar system. If the hypothetical Planet Nine does indeed exist, the sun probably ripped the world away from another star long ago, a new study suggests. "It is almost ironic that while astronomers often find exoplanets hundreds of light-years away in other solar systems, there's probably one hiding in our own backyard," study lead author Alexander Mustill, an astronomer at Lund University in Sweden, said in a statement. [The Evidence for Planet Nine in Pictures]. Earlier this year, astronomers Konstantin Batygin and Mike Brown, both of the California Institute of...

A mysterious planet that wiped out life on Earth millions of years ago could do it again, according to a top space scientist. And some believe the apocalyptic event could happen as early as this month. Planet Nine — a new planet discovered at the edge of the solar system in January — has triggered comet showers that bomb the Earth’s surface, killing all life, says Daniel Whitmire, of the University of Louisiana. The astrophysicist says the planet has a 20,000-year orbit around the sun and, at its closest to us, it knocks asteroids and comets toward Earth. Fossil evidence...

http://www.thescottishsun.co.uk/scotsol/homepage/7054203/Mysterious-planet-wiped-out-life-on-Earth-once-and-could-do-it-again-THIS-MONTH.html?redirect=true

Periodic mass extinctions on Earth, as indicated in the global fossil record, could be linked to a suspected ninth planet, according to research published by a faculty member of the University of Arkansas Department of Mathematical Sciences. Daniel Whitmire, a retired professor of astrophysics now working as a math instructor, published findings in the January issue of Monthly Notices of the Royal Astronomical Society that the as yet undiscovered "Planet X" triggers comet showers linked to mass extinctions on Earth at intervals of approximately 27 million years. Though scientists have been looking for Planet X for 100 years, the possibility...

And this new planet could be huge. Back in January, the astronomer who led the charge to have Pluto demoted to dwarf planet status announced that he’d just found evidence that a huge, icy planet could be lurking on the edge of the Solar System, just past Neptune. Mike Brown, a planetary astronomer at Caltech University, estimated that the hypothetical 'Planet Nine' appears to be circling the Sun on a super-elongated orbit that takes an incredible 10,000 to 20,000 years to complete. And now, thanks to a newly detected Kuiper Belt Object (KBO) that’s acting really strange, Brown says the...

Based on a careful study of Saturn's orbit and using mathematical models, French scientists were able to whittle down the search region for Planet Nine to "possible" and "probable" zones. Source: CNRS, Cote d'Azur and Paris observatories. Created by the author Astronomy, Cassini, Planet News, Solar SystemSearch Narrows For Planet Nine 25 Feb , 2016 by Bob King An imagined view from Planet Nine looking back toward the Sun. Astronomers think the massive, distant planet is gaseous, similar to the other giant planets in our Solar System. Credit: Wikipedia Last month, planetary scientists Mike Brown and Konstantin Batygin of...

Planet Nine - a newly proposed but not yet confirmed world perhaps 10 times more massive than Earth that's thought to orbit far beyond Pluto — probably could not have triggered such "death from the skies" events, researchers said. Planet Nine likely has an elliptical orbit, coming within 200 to 300 astronomical units (AU) of the sun at its closest approach and getting as far away as 600 to 1,200 AU, Brown said. (One AU is the distance from Earth to the sun - about 93 million miles, or 150 million kilometers). Neptune orbits about 30 AU from the sun,...

It’s a big, dark presence at the farthest reaches of our solar system, a mysterious force powerful enough to skew the paths of planets in orbit and yet so subtle that it slips undetected past even the most powerful telescopes on Earth. For centuries, it has eluded some of the most brilliant minds in astronomy — some say it even destroyed one. It’s the subject of endless calculations and rampant speculation, crackpot theories and countless hours spent gazing, fruitlessly, at the night sky. It’s known as Planet X. And on Tuesday, a group of astronomers said they’d found not just...