Cool astronomy news

Phil Plait brings us two amazing pieces of astronomy news. I can't add anything to what he's written so just check out his posts:

BREAKING: Martian avalanche caught in the act!

WR 104: A nearby gamma-ray burst?

Why are you still here?

Jumping Jupiter's Jets!

Ok, bad headline, but what can I say, I suck at headlines (if you haven't noticed that, you haven't been paying attention to my headlines).

Last March, astronomers observed some spectacular storms in the atmosphere of Jupiter, affecting the jet streams of Jupiter. It's not the first time this phenomenon has been observed, but this time it has lead to an international team looking into it.

According to ScienceDaily the team has been successful in understanding the phenomenon better.

Mystery Of Jupiter's Jets Uncovered

At the end of March 2007, scientists all over the world observed with surprise and awe a rare change in the atmosphere of Jupiter. A giant perturbation occurred amongst its clouds and two extremely bright storms erupted in the middle latitudes of the northern hemisphere, where its most intense jet stream - reaching speeds of 600 kilometers per hour – resides. Research into these unusual storms (previous ones had been seen in 1975 and 1990) and the reaction of the jet to them, undertaken by an international team coordinated by Agustín Sánchez-Lavega, from the Higher Technical School of Engineering of the University of the Basque Country (UPV/EHU), gives a more precise idea about the origin of these current flows and likewise can help to gain a better understanding of terrestrial meteorology.

Quite interesting. A what did they discover - well, let me quote the ScienceDaily article, as it explains it better than I could ever hope to do.

According to the study, the very bright storms are formed amongst the deepest clouds of water on the planet, rising vigorously and injecting a mixture of ice ammonia and water up to 30 km above the visible clouds. The storms move with the maximum velocity of the jet, - more than 600 kilometers per hour, creating disturbances and generating a stele of turbulence of reddish clouds that circle the whole planet. The infrared images show the brilliant festoons that make up the storms abandoning the jet stream to leeward.

Surprisingly, and despite the enormous amount of energy deposited by the storms and the mixture and whirlwinds generated thereby, the jet stream stayed practically still during all this perturbation and, when it was over, this stayed robust, despite the event suffered. The computer models simulating the progress of the phenomenon suggested that the jet stream goes deep into Jupiter’s atmosphere, to more than 100 km below the visible cloud level and where solar energy cannot reach.

This confirms the results previously obtained by the Galileo probe when it penetrated Jupiter’s atmosphere in December 1995. Although the regions studied are meteorologically different, everything points to Jupiter’s jet streams going very deep and suggests that the internal energy source plays an important role in its generation, states Mr Sánchez-Lavega

Quite fascination, though I am a little at lost of what it can tell us about our own planet's meteorology. Since it's way outside my field, I will take their words for it though.

The research is covered in the current issue of Nature, unfortunately behind a pay-wall. If you have access, it can be found here

The other side of Mercury

The NASA spacecraft MESSENGER has managed to orbit Mercury, and take a picture of the previously unseen side of Mercury, giving us the first glimpse.

You can see the picture at NASA's MESSENGER website.

Edit: National Geographic has more

Europe's role in today's astronomy

ScienceDaily has an article about the subject of Europe's role in astronomy today.

Europe Plays Lead Role In New Age Of Astronomical Discovery

Astronomy is entering a new golden age of discovery led by breakthroughs in telescopes and instruments making them capable of observing distant events early in the life of the universe. There is now great optimism that one of the fundamental questions of cosmology, the origin of galaxies, will be resolved within the next decade or sooner. But the technology involved is expensive, for instruments have to be highly sensitive and some of the observation needs to take place from space beyond the interference of the earth's atmosphere, so an international effort is involved.

Europe is playing a key role in this global programme with three new instruments, including the €1 billion Herschel Space Observatory (HSO), and the European Science Foundation (ESF) has been helping to coordinate the effort by bringing many of the principle users of these facilities together at an international conference. Delegates included leading specialists in all aspects of galaxy and star formation.

Europe has always had a strong tradition for involvement in astronomy (many of the early pioneers were European after all), but it's good to see that Europe still keeps on investing money in such research.

Neutron stars hotter than expected

It's always nice to see one's field of study get applied to real problems in other science fields, and even if it's more math than computer science, a new theoretical thermometer has made it possible for astrophysicians to come closer to understanding why superbursts happens on neutron stars.

ScienceDaily has the story.

Neutron Star Surfaces Hotter Than Expected, Helps Explain Superburst Frequency

A new theoretical thermometer built from heavy-duty mathematics and computer code suggests that the surfaces of certain neutron stars run significantly hotter than previously expected. Hot enough, in fact, to at least partially answer an open question in astrophysics -- how to explain the observed frequency of ultra-violent explosions known as superbursts that sometimes ignite on such stars' surfaces?

"This is the first model that goes into some reasonable detail about the nuclear physics that occur in the crusts of accreting neutron stars," said Hendrik Schatz, NSCL professor and co-author of a paper that will be published in The Astrophysical Journal in June.

I wasn't aware that the subject of superbursts was such a mystery, but aparently it is.

Though hardly subtle astrophysical phenomena, superbursts remain shrouded in some mystery, largely because only twelve of the extreme events have ever been observed. This mystery is what attracted the attention of researchers participating in the Joint Institute for Nuclear Astrophysics, or JINA, project.

I like the first sentence of that paragraph.

Interestingly enough the article doesn't actually state how hot the astrophysicians think the neutran stars are, but it does explain that while this new knowledge helps explaining superbursts, it's not sufficient to explain the frequency of them.

At least in part, this newly discovered heat helps to reconcile the work of theorists and experimentalists who study neutron stars. Prior to Schatz and Brown's research, theoretical astrophysicists predicted that superbursts should occur every ten years or so. Now, according the new calculation, theorists can explain why the gigantic explosions should occur every three or four years.

But more work remains to be done. According to observational data, superbursts occur roughly annually -- and scientists still aren't altogether sure why.

Maybe the stars are even hotter?

Total destruction not imminent

It seems that Earth is not at risk for getting destroyed by any large objects from space any time soon.

'Planet Killer' Not in the Stars, Asteroid Research Indicates (Washington Post)

The key paragraph related to this:

The chairman of this week's Planetary Defense Conference, William Ailor of the Aerospace Corp., a nonprofit established by Congress to support the Air Force's space defense program, said scientists generally agree that the risk to Earth from large asteroids is small. Researchers have identified more than 700 of these potential "planet killers" -- out of an estimated 1,000 -- and found that not one is on a collision course with Earth.

"But with the smaller ones, the asteroids in the [150-yard] range, we're finding more and more," Ailor said yesterday. "They're hard to detect, and it's hard to predict where they are headed, but they can do a great deal of damage." NASA estimates that there are as many as 100,000 of the smaller asteroids in near-Earth orbit and that about 20 are "potentially hazardous."

US politicians are calling for NASA to come up with a program for protecting the Earth against these smaller objects.