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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...

In January, researchers at Caltech in the US suggested a large, additional planet might be lurking in the icy outer reaches of the Solar System. Now, a team at the University of Bern in Switzerland has worked out what they say are upper and lower limits on how big, bright and cold it might be. The study has been accepted by the journal Astronomy and Astrophysics. Prof Mike Brown and Dr Konstantin Batygin made their case for the existence of a ninth planet in our Solar System orbiting far beyond even the dwarf world Pluto. There are no direct observations...

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...

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,...

Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun. The researchers, Konstantin Batygin and Mike Brown, discovered the planet's existence through mathematical modeling...

Scientists have been wondering whether a "Planet X" exists in the dim regions far beyond the known planets, but it has remained largely speculative.... That started to change in March 2014, when a pair of astronomers announced that they’d discovered a brand-new dwarf planet, 2012 VP113, beyond the well-populated edge of the Kuiper belt, whose main mass stretches from Neptune’s orbit around 30 astronomical units (or 30 times the Earth-Sun distance) out to 50 astronomical units. It wasn’t the only such object: Sedna, a 600-mile-wide rock discovered in 2003, also boasted this far-out orbit, and it seemed to be making...

There might be a ninth planet in the solar system after all - and it is not Pluto. Two astronomers reported on Wednesday that they had compelling signs of something bigger and farther away — something that would definitely satisfy the current definition of a planet, where Pluto falls short. "We are pretty sure there's one out there," said Michael E. Brown, a professor of planetary astronomy at the California Institute of Technology. What Dr. Brown and a fellow Caltech professor, Konstantin Batygin, have not done is actually find that planet, so it would be premature to revise mnemonics of...

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...

One thing we know for sure is that conditions on Earth were, shall we say, unpleasant for the dinosaurs at the moment of their demise. Alternate and overlapping theories suggest the great beasts were pelted with monster comets, drowned by mega-tsunamis, scorched with lava, starved by a landscape stripped of vegetation, blasted with the radiation of a dying supernova, cloaked in decades of darkness, and frozen in an ice age. Now, a pair of researchers have new evidence to support a link between cyclical comet showers and mass extinctions, including the one that they believe wiped out the dinosaurs 66...

136108 Haumea — one of the strangest worlds of them all — was introduced into the solar system menagerie about ten years ago. Discovered by Mike Brown (@Plutokiller extraordinaire) and team in late December 2004 from the Palomar Observatory, Haumea (say HOW-meh) received its formal name on September 17, 2008 along with its dwarf planet designation. Haumea is a fast rotator, with a ‘day’ equal to about four hours. We know this due to periodic changes in brightness. Haumea also has a high albedo of about 80%, similar to freshly fallen snow. Models suggest that Haumea is about twice as...

The paper ... noted that a number of large, very remote objects share a similar orbital angle. That's suspicious if you're an astronomer expecting to see a random distribution of objects. The key orbital feature is known, rather obtusely, as the “argument of perihelion.” We're not shy of complicated orbital concepts (we try to toss around the phrase "obliquity of the ecliptic" whenever possible), but this one is not very easy to explain. "The argument of perihelion is the angle at which an object comes to perihelion with respect to the ecliptic plane," Sheppard said in an e-mail. Mike Brown,...

Presently, our solar system is known to contain 4 fully-fledged rocky worlds: Mercury, Venus, Earth and Mars; 2 ice-giants: Neptune and Uranus; 2 gas-giants, Saturn and Neptune; 5 dwarf-planets, Ceres. Pluto, Eris, MakeMake, Haumea; around 100 moons; and an unknowable number of comets, asteroids and minor planets. Indeed, we’ve only begun to understand the full scope of our local corner of our galaxy, and new information emerges on a monthly-basis, yet there a number of seemingly obvious things that remain unknown. For instance, long before Pluto’s existence was deduced, astronomers scoured the outer solar system in search of another large...

In their studies, the team analyzed the effects of what is called the ‘Kozai mechanism,’ which is related to the gravitational perturbation that a large body exerts on the orbit of another much smaller and further away object. They looked at how the highly eccentric comet 96P/Machholz1 is influenced by Jupiter (it will come near the orbit of Mercury in 2017, but it travels as much as 6 AU at aphelion) and it may “provide the key to explain the puzzling clustering of orbits around argument of perihelion close to 0° recently found for the population of ETNOs,” the team...