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Rather, the comet's behavior is probably typical for comets making their first trip toward the sun — we just haven't been able to observe it before. "What makes this comet special is that it was discovered early," Jewitt said. "We've been able to follow the way the comet changes with distance from the sun over a much larger range than has ever been done before." Comet K2 comes from even farther away than the Kuiper Belt, Jewitt said. The comet's original home was most likely the Oort Cloud, the repository of comets and planetary fragments that extends from 2,000 to...

Astronomers have never directly seen the Oort Cloud and the most distant spacecraft ever launched by humankind – Voyager 1 – is not due to get there for another 300 years. But new research and upcoming space missions are now starting to reveal some of its secrets. The Oort Cloud was first predicted by Jan Oort in 1950 to explain the existence of comets like Neowise. Unlike short-period comets, which usually take less than 200 years to orbit the Sun and come from an icy disk beyond Neptune called the Kuiper Belt, the origin of those with much longer orbits...

Our sun has had close encounters with other stars in the past, and it’s due for a dangerously close one in the not-so-distant future. Every 50,000 years or so, a nomadic star passes near our solar system. Most brush by without incident. But, every once in a while, one comes so close that it gains a prominent place in Earth’s night sky, as well as knocks distant comets loose from their orbits. The most famous of these stellar interlopers is called Scholz’s Star. This small binary star system was discovered in 2013. Its orbital path indicated that, about 70,000 years...

A group of astronomers from the US, Europe, Chile and South Africa have determined that 70,000 years ago a recently discovered dim star is likely to have passed through the solar system's distant cloud of comets, the Oort Cloud. No other star is known to have ever approached our solar system this close - five times closer than the current closest star, Proxima Centauri. In a paper published in Astrophysical Journal Letters, lead author Eric Mamajek from the University of Rochester and his collaborators analyzed the velocity and trajectory of a low-mass star system nicknamed "Scholz's star." The star's trajectory...

Scholz's star -- named after the German astronomer who discovered it -- approached less than a light-year from the Sun. Nowadays it is almost 20 light-years away, but 70,000 years ago it entered the Oort cloud, a reservoir of trans-Neptunian objects located at the confines of the solar system. ... Now two astronomers from the Complutense University of Madrid, the brothers Carlos and Raúl de la Fuente Marcos, together with the researcher Sverre J. Aarseth of the University of Cambridge (United Kingdom), have analyzed for the first time the nearly 340 objects of the solar system with hyperbolic orbits (very...

The Hubble Space Telescope captured a view of Comet C/2017 K2 (PANSTARRS), called K2 for short, as it came in from out beyond Saturn's orbit, 1.5 billion miles from the sun. As it approaches the sun and the temperature rises from minus 440 degrees Fahrenheit, the comet is developing a fluffy cloud of dust, called a coma, which surrounds its frozen body. While the comet's nucleus appears to be just 12 miles across, the coma stretches 10 times Earth's diameter. According to a statement from NASA, K2 likely began its journey in the spherical Oort Cloud surrounding the solar system,...

To our Solar System, “close-encounters” with other stars happen regularly – the last occurring some 70,000 years ago and the next likely to take place 240,000 to 470,000 years from now. While this might sound like a “few and far between” kind of thing, it is quite regular in cosmological terms. Understanding when these encounters will happen is also important since they are known to cause disturbances in the Oort Cloud, sending comets towards Earth. Thanks to a new study by Coryne Bailer-Jones, a researcher from the Max Planck Institute for Astronomy, astronomers now have refined estimates on when the...

A duo of planetary astronomers has grabbed media attention by claiming a planet four times the size of Jupiter may be lurking in the outer solar system. They call the planet Tyche. Many astronomers, however, say it probably isn't there. The claim by John Matese and Daniel Whitmire of the University of Lousiana-Lafayette is not new: They have been making a case for Tyche since 1999, suggesting that the giant planet's presence in a far-flung region of solar system called the Oort cloud would explain the unusual orbital paths of some comets that originate there.

Highlighted by astronomers at the University of Rochester and the European Southern Observatory, the star — nicknamed “Scholz’s star” — has a very low tangential velocity in the sky, but it has been clocked traveling at a breakneck speed away from us. In other words, from our perspective, Scholz’s star is fleeing the scene of a collision with us. “Most stars this nearby show much larger tangential motion,” said Eric Mamajek, of the University of Rochester. “The small tangential motion and proximity initially indicated that the star was most likely either moving towards a future close encounter with the solar...

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...

While asteroids residing in the inner solar system will pass quickly through such small fields, trans-Neptunian objects (TNOs) orbit the Sun much more slowly. For example, Pluto, at an approximate distance of 40 A.U. from the Sun, along with the object Eris, presently the largest of the TNOs, has an apparent motion of about 27 arc seconds per day – although for a half year, the Earth’s orbital motion slows and retrogrades Pluto’s apparent motion. The 27 arc seconds is approximately 1/60th the width of a full Moon. So, from one night to the next, TNOs can travel as much...

Stars Passing Close to the Sunby Paul Gilster on January 2, 2015 Every time I mention stellar distances I’m forced to remind myself that the cosmos is anything but static. Barnard’s Star, for instance, is roughly six light years away, a red dwarf that was the target of the original Daedalus starship designers back in the 1970s. But that distance is changing. If we were a species with a longer lifetime, we could wait about eight thousand years, at which time Barnard’s Star would close to less than four light years. No star shows a larger proper motion relative to...

The question about the origin of oceans on Earth is one of the most important questions with respect to the formation of our planet and the origin of life. The most popular theory is that water was brought by impacts of comets and asteroids. Data from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument aboard the European Space Agency’s Rosetta spacecraft indicate that terrestrial water did not come from comets like 67P/Churyumov-Gerasimenko. The findings were published today in the journal Science. Researchers agree that water must have been delivered to Earth by small bodies at a later...

Three's Company, but Two's a Cloud? by Brian Thomas, M.S., and Jason Lisle, Ph.D. * It's not a planet, nor a comet, but the faraway object named 2012 VP113 now joins Sedna as only the second member of what secularists term the "inner Oort cloud." First, can we really infer the existence of a whole cloud from merely two objects? Second, this "cloud" presents a mystery—these objects should not even be there. How could they have traveled there, and what do they really represent? The two objects orbit the sun on highly eccentric tracks far beyond Neptune, the most distant...

<p>LOS ANGELES (AP) — Peering into the far reaches of the solar system, astronomers have spied a pink frozen world 7½ billion miles from the sun.</p> <p>It's the second such object to be discovered in a region of space beyond Pluto long considered a celestial wasteland. Until now, the lone known resident in this part of the solar system was an oddball dwarf planet spotted in 2003 named Sedna after the mythological Inuit goddess who created the sea creatures of the Arctic.</p>

The newest episode of "Cosmos: A Spacetime Odyssey" dove into all things big and small including the history of modern science. Aired Sunday night (March 23), the third episode of the reboot of Carl Sagan's beloved TV show "Cosmos: A Personal Voyage" explains how knowledge of the workings of gravity, comets and the solar system changed the way that humans look at the stars and science.

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....

At least 5 percent of the comets orbiting our sun may have been stolen from other stars, scientists say. Our solar system is thought to include trillions of comets -- small chunks of rock and ice -- that circle the sun in a spherical swarm called the Oort cloud, a region that extendsabout 100,000 times the distance from the Earth to the sun in any direction. The average distance between the Earth and sun is 93 million miles (150 million kilometers). Now scientists suggest that many of these bodies may actually have originated around other stars and were snatched up...

Our sun may have a companion that disturbs comets from the edge of the solar system — a giant planet with up to four times the mass of Jupiter, researchers suggest. A NASA space telescope launched last year may soon detect such a stealth companion to our sun, if it actually exists, in the distant icy realm of the comet-birthing Oort cloud, which surrounds our solar system with billions of icy objects. The potential jumbo Jupiter would likely be a world so frigid it is difficult to spot, researchers said. It could be found up to 30,000 astronomical units from...