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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...

Explanation: February's five planet line-up stretches across a clear sky in this predawn scene. A hilltop Castell de Burriac looms in the foreground, overlooking the town of Cabrera de Mar near Barcelona, Spain, planet Earth. The mosaicked, panoramic image looks south. It merges three different exposure times to record a bright Last Quarter Moon, planets, seaside city lights, and dark castle ruins. Seen on February 1st the Moon was near Mars on the sky. But this week early morning risers have watched it move on, passing near Saturn and finally Venus and Mercury, sliding along near the ecliptic toward the...

The best planet in our solar system is not, as Adrienne LaFrance claimed several months ago, Jupiter. Nor is it Saturn, as Ross Andersen argued in a rebuttal last month. I teach science for a living, which means I have a hard time allowing misinformation to pass by uncorrected—and after reading those articles, I knew I had to step in before any more intellectual damage was done. The best planet is Uranus—Uranus the bizarre. Uranus the unique.

Explanation: As January closes and in the coming days of February, early morning risers can spot the five naked-eye planets before dawn. Though some might claim to see six planets, in this seaside panoramic view all five celestial wanderers were found above the horizon along with a bright waning gibbous Moon on January 27. Nearly aligned along the plane of the ecliptic, but not along a line with the Sun, the five planets are spread well over 100 degrees across the sky. Just arriving on the predawn scene, fleeting Mercury stands above the southeastern horizon in the golden light of...

Explanation: In Greek myth Prometheus was a Titan, known for bringing fire from Mount Olympus. But in modern times the name is given to is a small moon of Saturn, orbiting just inside Saturn's F ring. In a complex interaction, the tiny potato-shaped moon interacts with the icy ring particles creating structures along the F ring still not fully understood. One of the highest resolution views of Prometheus, this image of its pocked surface posing with the thin F ring in the background was taken during the Cassini spacecraft's close approach on December 6, 2015. Prometheus is about 86 kilometers...

The early morning sky is where the action is this first week of the year. We were out early this Monday morning as skies cleared over Central Florida on our yearly vigil for the Quadrantid meteors. Though only a handful of meteors graced the dawn skies, we were treated to a splendid line-up, including Jupiter, Mars, Spica, Antares, Saturn, Venus, the waning crescent Moon AND a fine binocular view of Comet C/2013 US10 Catalina. ... Venus and Saturn pass just 5' (that’s 1/6th the diameter of the Full Moon) apart on the morning of Saturday, January 9th. The conjunction (sometimes...

Skywatchers will have many opportunities in 2016 to see just how small we are in the universe. Four days into the new year, hundreds of meteors will dance across the night skies.... Come September, an outer ring of the sun's annular eclipse will be visible across Africa. In between, there will be spectacular shooting stars, super moons, and lunar eclipses to take in. ... From about Jan. 20 to Feb. 20, all five planets that are visible to the naked eye — Mercury, Venus, Mars, Jupiter and Saturn — will occupy the morning sky. This hasn't happened since 2005, according...

Most studies of potential Earth-smashers focus on objects in the asteroid belt roughly between Mars, Earth's outside neighbour, and Jupiter on its other flank, said the researchers. But they noted that the discovery in the last two decades of hundreds of giant comets dubbed centaurs, albeit with much larger orbits, requires expanding the list of potential hazards. These balls of ice and dust, typically 50-100 kilometres (31-62 miles) wide, have unstable, elliptical orbits that start way beyond Neptune, the most distant planet from the Sun. Their paths cross those of the giant planets Jupiter, Saturn, Uranus and Neptune, whose gravity...

Cassini is due to pass 3,106 miles from Enceladus at 12:49 p.m. EST. Scientists want to use the flyby to study how much heat is coming up through the ice from the moon's interior. The measurements will help researchers figure out what is driving Enceladus' plumes. "Understanding how much warmth Enceladus has in its heart provides insight into its remarkable geologic activity," Cassini project scientist Linda Spilker, with NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. Cassini will continue to observe Enceladus during the remainder of its mission, but it will be at least four times farther...

A University of Montana professor who studies astrophysics has discovered how water ions escape from Saturn's environment... UM Professor Daniel Reisenfeld is a member of the Cassini research team... One of the instruments on Cassini measures the planet's magnetosphere - the charged particles, known as plasma, that are trapped in the space surrounding Saturn by its magnetic field. One of Cassini's past discoveries is that Saturn's plasma comprises water ions, which are derived from Saturn's moon Enceladus, which spews water vapors from its Yellowstone-like geysers. Knowing that the water ions would not be able to accumulate indefinitely, the team of...

Explanation: Saturn's icy moon Enceladus poses above the gas giant's icy rings in this Cassini spacecraft image. The dramatic scene was captured on July 29, while Cassini cruised just below the ring plane, its cameras looking back in a nearly sunward direction about 1 million kilometers from the moon's bright crescent. At 500 kilometers in diameter, Enceladus is a surprisingly active moon though, its remarkable south polar geysers are visible venting beyond a dark southern limb. In fact, data collected during Cassini's flybys and years of images have recently revealed the presence of a global ocean of liquid water beneath...

Toronto– A close encounter with Jupiter about four billion years ago may have resulted in another planet’s ejection from the solar system altogether, scientists have found. The existence of a fifth giant gas planet at the time of the solar system’s formation — in addition to Jupiter, Saturn, Uranus and Neptune that we know of today — was first proposed in 2011, researchers said.

Using a new process in planetary formation modeling, where planets grow from tiny bodies called "pebbles," Southwest Research Institute scientists can explain why Mars is so much smaller than Earth. This same process also explains the rapid formation of the gas giants Jupiter and Saturn, as reported earlier this year. "This numerical simulation actually reproduces the structure of the inner solar system, with Earth, Venus, and a smaller Mars," said Hal Levison, an Institute scientist at the SwRI Planetary Science Directorate. He is the first author of a new paper published in the Proceedings of the National Academy of Sciences...

A FIFTH terrestrial planet may once have orbited between Mars and Jupiter. Although gravitational disturbances would have sent the planet hurtling into the sun or out into space long ago, traces of this long-gone world may still be visible in part of the asteroid belt today. Recent simulations have suggested that the gas giants of our solar system formed with circular orbits but moved into their more elongated paths about 4 billion years ago – 700 million years after the solar system formed. While the gas giants were in circular orbits, rocky planets should have formed in stable orbits out...

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...

WASHINGTON – Astronomers have found what appears to be a gigantic suicidal planet. The odd, fiery planet is so close to its star and so large that it is triggering tremendous plasma tides on the star. Those powerful tides are in turn warping the planet's zippy less-than-a-day orbit around its star. The result: an ever-closer tango of death, with the planet eventually spiraling into the star.

Habitable, Earth-like planets can form even after giant planets have barrelled through their birthplace on epic migrations towards their host stars, new computer simulations suggest. The finding contradicts early ideas of how planets behave and suggests future space missions should search for terrestrial planets near known "hot Jupiters". Many of the 160 or so known extrasolar planets are hot Jupiters - massive planets that are closer to their stars than Mercury is to our Sun. But the planets probably did not form in these scorching regions because there would not have been enough gas and dust there to amass such...

Early in our own solar system's history, the largest of these planetary embryos acquired a dense envelope of hydrogen and helium and transformed into the gas giants we know today... Planets that form far from their parent star are expected to have a composition similar to comets (50% rock, 50% water by weight). Once a planet exceeds about ten Earth masses it has enough gravity to attract any hydrogen and helium near its orbit, and will rapidly transform into a gas giant... [A planet] in this region that never exceed the threshold... becomes an "ocean planet", a term coined by...

Seeing Earth first from Mars and then from Saturn was indeed mind-boggling but the recent long distance image from Saturn of Venus really amazed me, especially since it occured over two years ago. Peering over the shoulder of giant Saturn, through its rings, and across interplanetary space, NASA's Cassini spacecraft spies the bright, cloudy terrestrial planet, Venus. The vast distance from Saturn means that Venus only shows up as a white dot, just above and to the right of the image center. Venus, along with Mercury, Earth, and Mars, is one of the rocky 'terrestrial' planets in the solar...

NASA's Cassini spacecraft zoomed by Saturn's icy moon Enceladus on Oct. 14, 2015, capturing this stunning image of the moon's north pole. A companion view from the wide-angle camera shows a zoomed out view of the same region for context. Scientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images from the Voyager mission, but high-resolution Cassini images show a landscape of stark contrasts. Thin cracks cross over the pole -- the northernmost extent of a global system of such fractures. Before this Cassini flyby, scientists did not know if the fractures extended so...