Saturn's 'day' shorter by five minutes

An analysis of Saturn's atmosphere has resulted in the definition of the planet's 'day' becoming somewhat shorter.
According to a study in the journal Nature, the time it takes the ringed behemoth to complete a spin on its axis is 10 hours, 34 minutes and 13 seconds, more than five minutes shorter than previous estimates.
Unlike a rocky planet, Saturn has no visual landmarks. Instead it is covered in clouds of gas driven by layers of jetstreams, making it hard to measure the planet's rotation.
As a result, astronomers have traditionally based their calculations on Saturn's magnetic field. But this signal can fluctuate and does not accurately measure how fast the planet's deep interior is rotating.
Dr Andrew Prentice of Monash University in Melbourne says the problem with using Saturn's magnetic field is that it changes over time.
"It does not give a proper measure of Saturn's internal rotation since the magnetic field is slipping relative to the planet," he says.
"As a result the period seems to have lengthened by seven to eight minutes since the time of the Voyager 1 and 2 missions in the mid-1980s."....



Astronomers say the new calculation shows the gas giants have similar properties

Mock Supernova Created by Supercomputer

new view of supernovas — the spectacular explosions of dying stars — has come not from a telescope, but from a powerful supercomputer simulation.
The simulated supernova, revealed in cut-away layers in the rendering, grew out of an effort to develop faster ways to build high-fidelity computer models of complex phenomena in the real world.
Performing a single run of a current model of the explosion of a star on a home computer would be next to impossible — it would take more than three years just to download the data. So scientists instead use supercomputers, which can handle processing quadrillions of data points at a time...

Mars Meteorite Reveals Clues Into Planet's Past

A meteorite the size of a huge watermelon on Mars is revealing new clues to the planet's environment

The Martian meteorite at least half a ton, making it much too large to have plunged through Mars' current thin atmosphere and hit the ground without being obliterated upon impact, rover scientists said. Either the atmosphere was thicker than expected some time in the relatively recent past, scientists figure, or the rock fell to the surface billions of years ago when the atmosphere was thicker.NASA's Opportunity rover
discovered the metallic meteorite - which scientists now call Block Island - in late July, then drove up to take a closer look.
"Consideration of existing model results indicates a meteorite this size requires a thicker atmosphere," said Matt Golombek, a rover team member at NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a statement. "Either Mars has hidden reserves of carbon-dioxide ice that can supply large amounts of carbon-dioxide gas into the atmosphere during warm periods of more recent climate cycles, or Block Island fell billions of years ago."
A planet's atmosphere can slow a meteorite's fall due to the friction the rock encounters as it plows through the atmosphere after flying in the relative vacuum of space.......

'Suicidal' Planet to be Swallowed by its Sun

Distant World May Have Less than a Million Years Before Falling Into Star it Orbits

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.
It's a slow death. The planet WASP-18b has maybe a million years to live, said planet discoverer Coel Hellier, a professor of astrophysics at Keele University in England. Hellier's report on the suicidal planet is in Thursday's issue of the journal Nature.
"It's causing its own destruction by creating these tides," Hellier said.
The star is called WASP-18 and the planet is WASP-18b because of the Wide Angle Search for Planets team that found them.
The planet circles a star that is in the constellation Phoenix and is about 325 light-years away from Earth, which means it is in our galactic neighborhood. A light-year is about 5.8 trillion miles.....

The fingerprint on Mars: High resolution imag...;s never been seen before

New high resolution images of the Red Planet show a range of dunes and craters that appears to form a giant cosmic fingerprint on the surface.
Thousands of the images have been captured by more than 1,500 telescopic observations by NASA's Mars Reconnaissance Orbiter, using a High Resolution Imaging Science Experiment (HiRISE) camera.
Each full image from HiRISE, taken between April and August last year, covers a strip of Martian ground six kilometers (3.7 miles) wide, showing details as small as one metre, or yard, across.

Just amazing !!