Stellary Starry Universe

SYDNEY: New evidence backs up the idea that a shockwave from the explosion of massive star triggered the collapse of a dense, dusty gas cloud to form our Sun and its retinue of planets.

For many decades astronomers have postulated that the after effects of this violent supernova led to the birth of the Solar System.

But detailed models of this formation process have only produced the right results under the simplifying – and likely wrong – assumption that the temperatures during the violent events remained constant.

Devil in the details

Now, U.S. astrophysicists at the Carnegie Institution, in Washington DC, have shown for the first time that a supernova could indeed have triggered the Solar System’s formation under the more likely conditions of rapid heating and cooling.

They argue that their results, published last month in the Astrophysical Journal, resolve a long-standing debate.

“We’ve had chemical evidence from meteorites that points to a supernova triggering our Solar System’s formation since the 1970s,” said Alan Boss, lead author of the study.

“But the devil has been in the details,” he said. “Until this study, scientists have not been able to work out a self-consistent scenario, where collapse is triggered at the same time that newly created isotopes from the supernova are injected into the collapsing cloud.”

Short-lived radioactive isotopes – versions of elements with the same number of protons, but a different number of neutrons – found in very old meteorites decay on time scales of millions of years and turn into different ‘daughter’ elements.

Source: Cosmos Online – click here or title for full article

 

 

 

Venus and Jupiter are converging for a spectacular three-way conjunction with the crescent Moon–a rare gathering some are calling ‘the sky show of the year.’ Today’s story tells when and where to look.

Nov. 24, 2008: This story ends with the best sky show of the year–a spectacular three-way conjunction of Venus, Jupiter and the crescent Moon.

It begins tonight with a sunset stroll.

At the end of the day, when the horizon is turning red and the zenith is cobalt-blue, step outside and look southwest. You’ll see Venus and Jupiter beaming side-by-side through the twilight. Glittering Venus is absolutely brilliant and Jupiter is nearly as bright as Venus. Together, they’re dynamite:

Source: Nasa Science – click here for full article

 

 

 

The solar wind appears to be ripping big chunks of air from the atmosphere of Mars. This could help solve a longstanding mystery about the Red Planet.

Nov. 21, 2008: Researchers have found new evidence that the atmosphere of Mars is being stripped away by solar wind. It’s not a gently continuous erosion, but rather a ripping process in which chunks of Martian air detach themselves from the planet and tumble into deep space. This surprising mechanism could help solve a longstanding mystery about the Red Planet.

Source: Nasa Science – click here or title for full article

 

Yesterday, NASA’s MESSENGER spacecraft flew past Mercury and photographed a broad swath of never-before-seen terrain. The first of more than 1,200 high-resolution images are now arriving back at Earth.

“The MESSENGER team is extremely pleased by the superb performance of the spacecraft and the payload,” said Sean Solomon, MESSENGER lead scientist at the Carnegie Institution of Washington DC.

“We are now on the correct trajectory for eventual insertion into orbit around Mercury, and all of our instruments returned data as planned,” he said…

Source: Nasa Science – click here or title for full article

 

 

 

Nov. 7, 2008: After two-plus years of few sunspots, even fewer solar flares, and a generally eerie calm, the sun is finally showing signs of life.

“I think solar minimum is behind us,” says sunspot forecaster David Hathaway of the NASA Marshall Space Flight Center.

His statement is prompted by an October flurry of sunspots. “Last month we counted five sunspot groups,” he says. That may not sound like much, but in a year with record-low numbers of sunspots and long stretches of utter spotlessness, five is significant. “This represents a real increase in solar activity.”

Source: Nasa Science – click here or title for full article