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From: TerryMoselaol.com
Date: Sun, 8 Jan 2006 11:26:45 EST
Subject: NY Party, Stardust, Amateurs & Neutrinos, IFAS Ast of the Year. 

Hi all,
1. Congrats to all who contributed to another excellent IAA NY  party! In 
particular, the 'Michelin Star' catering by IAA member Derwen  Campbell, which 
was just mouthwateringly delicious, not to mention copious! Also  to George 
Brannan for most of the arrangements & the quiz, Philip Baxter for  the quiz 
prizes, John Hall for the financial aspect, & Danny Collins for  help with the 
drinks. And my hot punch seemed more popular than ever, with some  coming back for 
not just seconds and thirds, but at least one fourth! 
   It was so good that we even forgave John O'Neill, John  Flannery & Gerry 
Moloney from Dublin, Rush (obviously not well  named!) & Kells, for arriving 
almost an hour late!
2. STARDUST (the other one!).
The only space mission named after an astronomy club magazine, "STARDUST",  
will return to Earth on 15 January, with a sample of comet dust, and  a planned 
touchdown in Utah.

Just before 3 a.m. MST, the spacecraft will jettison its return  capsule, 
which will plunge into Earth's atmosphere at nearly 29,000 miles per  hour, the 
greatest return speed ever recorded. A few moments later, after the  capsule 
slows to just faster than the speed of sound, a parachute will apply the  brakes 
and Stardust will settle to the ground on the Air Force's Utah Testing  and 
Training Range southwest of Salt Lake City.  
The return capsule contains tiny bits of dust captured two years ago as it  
spewed from a comet called Wild 2. The tennis-racquet-shaped collector used a  
remarkably light and porous material called aerogel to capture the particles,  
each much smaller than a grain of sand and traveling six times the speed of a 
 bullet fired from a rifle. Earlier, the reverse side of the collector snared 
 interstellar dust grains flowing into the solar system from other stars in 
our  galaxy. In all, the capsule contains tens of thousands of comet grains and 
about  100 bits of interstellar dust.  
"It's really quite an epic thing. I think it tends to get overlooked because  
it's just a little mission, and there aren't any people on board," said D.  
Brownlee, University of Washington, Pricipal Investigator. "But the really big  
part of the research is just getting ready to start, when the material goes 
to  the laboratory. The train is headed for the station and we're all waiting 
for  it."  
Stardust is part of NASA's series of Discovery missions and is managed by the 
 Jet Propulsion Laboratory in Pasadena, Calif. Besides the UW, other  
collaborators are Lockheed Martin Space Systems; The Boeing Co.; Germany's  
Max-Planck Institute for Extraterrestrial Physics; NASA's Ames Research Center;  and 
the University of Chicago.  
After the capsule touches down in the Utah desert, a canister bearing the  
aerogel collector grid will be removed and taken to the Johnson Space Center in  
Houston, where the samples will be cataloged and sent to scientists around 
the  world. Brownlee expects them to provide key information on the formation of 
the  solar system 4.6 billion years ago and possibly to shed light on the 
origins of  life on Earth. Scientists are likely to study Stardust's treasure for 
decades to  come.  
Stardust was launched on Feb. 7, 1999, and set off on three giant loops  
around the sun. It began collecting interstellar dust in 2000 and met Wild 2  
(pronounced Vilt 2) on Jan. 2, 2004, when the spacecraft weathered a hailstorm  of 
comet particles and snapped exceptional close-up photographs of the comet's  
surface. During its 2.88 billion-mile voyage Stardust made one pass by Earth 
to  get a speed boost from the planet's gravity, and later staged a 
dress-rehearsal  for the comet encounter when it maneuvered very close to Asteroid 5535  
The tensest moment other than the comet encounter came in November 2000,  
while the spacecraft was cruising along some 130 million miles from the sun. A  
huge solar flare, 100,000 times more energetic than usual, engulfed Stardust 
and  its special digital cameras that help the spacecraft know where it is by 
viewing  the stars and making comparisons with a comprehensive star chart stored 
in the  onboard computer. The high-energy solar flare electrified pixels in 
the cameras,  producing dots that the computer interpreted as stars. Suddenly th
e spacecraft  did not know where it was and, in a preprogrammed act of 
self-preservation, it  turned its solar panels toward the sun, losing communication 
with Earth.  
Ground controllers finally found a faint signal and were able to contact  
Stardust and correct the problem. A little more than three years later the  
spacecraft finally met the target that scientists had been aiming for since  1974, 
when a close encounter with Jupiter altered Wild 2's orbit and brought it  to 
the inner solar system. That made the mission feasible.  
Scientists have collected thousands of meteorites and cosmic dust particles  
on Earth, Brownlee noted, but with few exceptions the origin of those 
materials  is unknown. Now there will be samples of material from another known body 
in  space, and those grains can be compared with all the previously collected  
meteorites and bits of dust to see if there are similar origins. The Wild 2  
samples are cryogenically preserved solar system building blocks, kept close to 
 their original state because they have existed mostly at the outer edge of 
the  solar system.  
"Virtually all the atoms in our bodies were in little grains like the ones  
we're bringing back from the comet, before the earth and sun were formed,"  
Brownlee said. "Those grains carry elements like carbon, nitrogen and silicon  
from one place to another within our galaxy, and they helped form the sun, the  
planets and their moons."  
Stardust's photographs of Wild 2 also are cause for further study. Brownlee  
still marvels at the rugged surface the pictures disclosed, a surface very  
different from the smoother cores of the other three comets - Tempel 1, Borrelly 
 and Halley - that have been photographed up close.  
"For unknown reasons, the surface of Wild 2 looks quite different -  
spectacularly different - from asteroids, moons, planets and even from other  comets," 
he said.  
scientists have thought of a new way to solve an astronomical mystery, and their  
plan relies on a well-connected network of amateur stargazers and one very  
elusive subatomic particle.  
To understand what happens inside exploding stars, or supernovae, scientists  
need to study particles called neutrinos, explained John Beacom, assistant  
professor of physics and astronomy at Ohio State University. Neutrinos are  
formed in the nuclear reactions that make stars like our sun shine. Exploding  
stars overflow with the particles, and flood the universe with them.  
Neutrinos should be everywhere, but they are very hard to detect - so hard to 
 detect, in fact, that even though countless neutrinos burrow through our 
planet  every second, scientists only capture a few of them each day.  
Scientists know that most neutrinos they do detect probably come from our own 
 sun, from nuclear reactors in terrestrial power plants, or from cosmic 
radiation  interacting with our atmosphere. There has been no way to distinguish 
whether a  particular neutrino came from elsewhere, until now.  
That's why Beacom and his team's discovery - that each year, one or two of  
the neutrinos detected on Earth can probably be matched to the exploding star  
that made them - represents a major step forward for supernova astrophysics.  
The discovery also comes at a special time, Beacom said. The method will  
fully exploit the capabilities of the next generation of neutrino detectors,  
which are now being planned, and take advantage of a growing number of amateur  
astronomers who are capable of discovering supernovae.  
For a study appearing in a recent issue of the journal Physical Review  
Letters, Beacom and his coauthors developed a kind of litmus test for finding  
supernova neutrinos: If a detector on Earth registers two of the particles  within 
ten seconds, odds are high that they came from a supernova in a nearby  
galaxy. Alternatively, if an astronomer - amateur or otherwise - spots a  
supernova, scientists at neutrino detectors can look back through their records  to see 
if they captured a neutrino around that time.  
Given that a few supernovae occur in nearby galaxies every year, and given  
the sensitivity of neutrino detectors on Earth, they've determined that at 
least  one of those scenarios - the two-in-ten-seconds event or the identification 
of a  supernova neutrino after the fact - should be able to happen about once 
a year.  
The professionals need amateur astronomers to help spot new supernovae fast,  
so scientists can quickly match captured neutrinos with the exploding stars 
that  made them.  
"Even with all our modern telescopes, the professionals can't look at the  
whole sky at once," Beacom said. "But the amateurs are everywhere. With  
relatively small telescopes, they can see these nearby supernovae, which are  very 
bright - often brighter than their host galaxies."  
Coauthor Hasan Yuksel, a postdoctoral researcher at Ohio State, explained  
that many of today's so-called amateur astronomers aren't really so amateur.  
"You can think of them more as 'professional amateurs,'" he said.  
These are the semi-pro players of the hobby set - skilled folks who build  
custom telescopes. They have day jobs, but they scan the skies at night, and  
share their findings with other amateurs over the Internet. Often, they have  
ties to professional astronomers. When a major discovery is made, they know as  
soon as the professionals do.  
Yuksel also pointed out that since 2002, there were at least nine supernovae  
identified in galaxies within about 30 million light years (180 trillion 
miles)  of our Milky Way, and more than half of those were discovered by amateurs. 
Surprisingly, the Ohio State physicists got their idea in a "eureka" moment  
-- after a discussion with colleagues at the Department of Astronomy's morning 
 coffee event. This daily review of new journal papers posted to an online  
archive (arXiv.org) has been going on since the 1990s, and often 
inspires  faculty and students to pursue new lines of research.  
Walking back to their offices after coffee, Yuksel asked Beacom and visiting  
scholar Shin'ichiro Ando about a special class of galaxies called starburst  
galaxies, in which unusually high numbers of stars are being born. Wouldn't  
those galaxies also have large numbers of supernovae? Wouldn't nearby starburst 
 galaxies be good places to look and find out?  
Beacom said that something clicked. "We realized that maybe it's not totally  
crazy to look for neutrinos from supernovae in nearby galaxies," he said.  
The three performed detailed calculations about supernova rates in nearby  
galaxies, and found that the explosions probably happen more often than people  
once thought - about three times a year. Then they looked at the rates at 
which  neutrinos are caught in giant underground detectors on Earth.  
Their discovery came down to calculating the odds: it's highly unlikely that  
a neutrino detector on Earth would capture two particles within any 10 second 
 interval unless both of those neutrinos came from a supernova - in fact, the 
 same supernova.  
"We were kicking ourselves for not thinking of this before," Beacom said.  
He cited Supernova 1987A, which occurred in a galaxy that is a very close  
companion to the Milky Way. Because detectors on Earth captured 20 neutrinos in  
only a few seconds during that event, astronomers knew for sure that they 
came  from 1987A.  
But since then? "A big fat zero," he said. "What if using this technique, we  
could have been identifying one additional supernova neutrino per year? By 
now,  we would have collected a sample as big as that burst in 1987." With the 
much  larger neutrino detectors that are now being devised, and with the large 
number  of supernovae that are being spotted these days, it could be done.  
Galaxies up to 200 times farther away than the one that spawned Supernova  
1987A are still considered near by astronomical standards, and amateurs would be 
 able to spot supernovae in them. Those galaxies may give us only one or two  
neutrinos per year, but that's still more than scientists would be able to 
study  otherwise.  
"These are somewhat desperate measures," Ando admitted. "Why are we so  
desperate? Since a supernova expends 99 percent of its energy in neutrinos,  those 
neutrinos tell the story of how the explosion works, and therefore we have  to 
find them." Supernova neutrinos are everywhere, but the vastness of space  
keeps them hidden.  
So, at least a thousand years after people first noticed supernovae in the  
skies, what's happening inside these exploding stars is still a mystery. When  
scientists simulate supernovae on computer, something always goes wrong. The  
explosion starts, and then it fizzles.  
"If we can't make a supernova blow up on the computer, that means we're  
missing something. We need clues. We need to find those neutrinos," Ando  
Beacom envisions that scientists at neutrino detectors could sound an alarm  
whenever they detect two particles in ten seconds. Since supernovae emit  
neutrinos at the very start of the explosion, the particles would reach Earth  
hours before the supernovae would be visible in telescopes, and the announcement  
would amount to a supernova forecast.  
Alternatively, when astronomers spot a nearby supernova, they could ask the  
scientists at the detectors to look back through their data from previous 
hours  to find any particle events.  
At Beacom's suggestion, scientists working at the Japanese neutrino detector  
Super-Kamiokande are going to search their records for events that could be  
linked to nearby supernovae in past years.  
"While this detector is smaller than those envisioned for the future, it's  
been in operation for a decade or two, so it actually stands a good chance of  
having detected the first neutrino from an identified supernova beyond the 
Milky  Way and its closest companions," Beacom said.  
4. IFAS Amateur Astronomer of the year:  Congratulations to Martin McKenna of 
EAAS, from Maghera, County Derry,  who is the IFAS Astronomer of the Year 
2005 as voted by his peers.   And he thoroughly deserves it for his tireless 
observing AND for sharing it on  the IFAS boards.  It reflects the time and effort 
he spends in comet  hunting and deep sky observing. Martin has also recently 
started a nova patrol  and has reported observing many atmopspheric
phenomena including the  Gegenshein and many lunar and solar haloes, upper 
tangential arcs and much more.  His most recent observing includes seeing 
Asteriod Vesta with the unaided  eye.
And an honourable mention should go to his tireless  companion - Conor, of 
the IAA, Co. Derry. 
Clear Skies, 
Terry  Moseley


Last Revised: 2006 January 9th
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