Free Republic

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,...

There’s something odd floating around in the outer solar system. Actually, there’s lots of odd things floating around in the outer solar system, but 2002 UX25 is one of the most baffling. The mid-sized Kuiper belt object (KBO) measures 650 kilometers (400 miles) across, and yet it has a density less than water (less than 1 gram per cubic centimeter). Yes, if you put it in a huge bathtub, 2002 UX25 would float. ...planetary scientist Mike Brown, of the California Institute of Technology (Caltech) in Pasadena, has taken a measure of 2002 UX25′s density and discovered that it is “the...

Many galaxies appear to have stronger gravity - and thus more mass - than can be explained by their visible matter alone. Overly massive galaxies are most often attributed to dark matter, an invisible substance that interacts with matter through gravity. To date, though, no one has directly detected dark matter particles. But a well-established notion in physics could hold another explanation for their size. This says that empty space is really a frothy, turbulent sea full of virtual particles - matter and antimatter that spring in and out of existence so fast that we can't see them. Though they...

Small objects could be rounded worlds, based on likely sizes, experts say. Three relatively bright space rocks recently found in Pluto's neighborhood may be new members of the dwarf planet family, astronomers say. The objects were discovered in a little studied section of the Kuiper belt, a region of the solar system that starts beyond the orbit of Neptune and extends 5.1 billion miles (8.2 billion kilometers) from the sun. Astronomer Scott Sheppard, of the Carnegie Institute of Washington, and colleagues found the bodies using the 1.3-meter Warsaw University Telescope at Las Campanas in Chile. The region of the Kuiper...

Nasa scientists are searching for an invisible 'Death Star' that circles the Sun, which catapults potentially catastrophic comets at the Earth. The star, also known as Nemesis, is five times the size of Jupiter and could be to blame for the impact that wiped out the dinosaurs 65 million years ago. The bombardment of icy missiles is being blamed by some scientists for mass extinctions of life that they say happen every 26 million years Nemesis is predicted to lie at a distance equal to 25,000 times that of the Earth from the Sun, or a third of a light-year....

A distant, icy rock whose discovery shook up the solar system and led to Pluto's planetary demise has been given a name: Eris. The christening of Eris, named after the Greek goddess of chaos and strife, was announced by the International Astronomical Union on Wednesday. Weeks earlier, the professional astronomers' group stripped Pluto of its planethood under new controversial guidelines. Since its discovery last year, Eris, which had been known as 2003 UB313, ignited a debate about what constitutes a planet. Astronomers were split over how to classify the object because there was no universal definition. Some argued it should...

If you can make sense of it, here's the article: Stellar encounters as the origin of distant Solar System objects in highly eccentric orbits SCOTT J. KENYON AND BENJAMIN C. BROMLEY The Kuiper belt extends from the orbit of Neptune at 30 AU to an abrupt outer edge about 50 AU from the Sun. Beyond the edge is a sparse population of objects with large orbital eccentricities. Neptune shapes the dynamics of most Kuiper belt objects, but the recently discovered planet 2003 VB12 (Sedna) has an eccentric orbit with a perihelion distance of 70 AU, far beyond Neptune's gravitational influence....

When is a planet not a planet? That is what astronomers will be asking themselves after yesterday's announcement of the biggest planetary body discovered in the solar system in more than 70 years. The new body, called Quaoar (pronounced Kwah-o-ar), is a round world that orbits the sun every 288 years, at a distance greater than that of any of the nine planets. At 1250 kilometres wide, it is bigger than any of the asteroids. In fact, it is bigger than all the asteroids put together. But it is also just over half the size of the smallest planet in...

2015 TG387, a newfound object in the far outer solar system, way beyond Pluto. The orbit of 2015 TG387 shares peculiarities with those of other extremely far-flung bodies, which appear to have been shaped by the gravity of a very large object in that distant, frigid realm — the hypothesized Planet Nine, also known as Planet X. "These distant objects are like breadcrumbs leading us to Planet X," And 2015 TG387 is special among these bread crumbs, because it was found during a relatively uniform survey of the northern and southern skies rather than a targeted hunt for clustered objects...

Centaurs are a population of objects within our Solar System that behave as both comets and asteroids (hence why they are named after the hybrid beasts of Greek mythology). 10199 Chariklo is the largest known member of the Centaur population, a possible former Trans-Neptunian Object (TNO) which currently orbits between Saturn and Uranus. The rings around this asteroid were first noticed in 2013 when the asteroid underwent a stellar occultation. This revealed a system of two rings, with a radius of 391 and 405 km and widths of about 7 km 3 km, respectively. The absorption features of the rings...

Explanation: The night side of Pluto spans this shadowy scene. The spacebased view with the Sun behind the distant world was captured by New Horizons last July. The spacecraft was at a range of over 21,000 kilometers, about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto's tenuous, surprisingly complex layers of hazy atmosphere. The crescent twilight landscape near the top of the frame includes southern areas of nitrogen ice plains informally known as Sputnik Planum and rugged mountains of water-ice in the Norgay Montes.

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...

The object, 2000 EB173, was found in March using data collected by a 39-inch (1-meter) telescope at the CIDA Observatory in Venezuela. The space rock is estimated at about one-quarter the size of Pluto and joins a club of more than 300 other "trans-Neptunian objects," small bodies that orbit the Sun beyond Neptune... Charles Baltay, a Yale University physicist who headed up the investigation [said] ... "We believe that this thing has been orbiting since the formation of the solar system. So it's the primordial stuff, and it's bright enough that we can study it in detail." The object appears...

The Oort Cloud is a theoretical spherical cloud of predominantly icy planetesimals that is believed to surround the Sun at a distance of up to around 100,000 AU (2 ly). This places it in interstellar space, beyond the Sun’s Heliosphere where it defines the cosmological boundary between the Solar System and the region of the Sun’s gravitational dominance. Like the Kuiper Belt and the Scattered Disc, the Oort Cloud is a reservoirs of trans-Neptunian objects, though it is over a thousands times more distant from our Sun as these other two. The idea of a cloud of icy infinitesimals was...