25 November 2008

Giant Camera Tracks Asteroids

Giant Camera Tracks Asteroids
The camera will offer sharper, broader views of the sky.
By Robert Lemos

The first of four new asteroid-tracking telescopes will come online next month in Hawaii, promising to quickly scan large swaths of the sky--thanks to the world's largest digital camera.

The project, known as the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), aims to scan the entire sky visible from the summit of Mount Haleakala in Maui Island, Hawaii, three times a month, searching for asteroids and near-Earth objects (NEOs) as small as 300 meters in diameter. At the heart of each telescope is a 1.4-billion-pixel digital camera that can photograph broad swaths of the night sky in sharp detail.

The first prototype telescope using the camera will go online in December. This telescope will scan the night sky, searching for asteroids and comets that could pose a threat to Earth. Pan-STARRS is designed to have at least three times the collecting power of current NEO telescopes.

The Pan-STARRS's cameras, each consisting of a 40-centimeter-square array of charge-coupled devices (CCDs), bring new technology to the optics used in astronomy. Perhaps the most innovative aspect is the ability of each CCD cell to electronically shift an image to counteract atmospheric blur and deliver clearer astrophotography, says Barry Burke, a senior staff member at MIT's Lincoln Laboratory, which makes the cameras.

"The atmosphere is the limit to the quality of the image, but there is a special feature of these chips that allows them to remove some of the blur due to atmospheric effects," Burke says. "It allows the image to be shifted in any direction in the chip in a way that matches the motion of the stars and that takes out a significant part of the blur."

Known as orthogonal transfer CCD (OTCCD), the technology uses electronics to adjust the image rather than mechanically tilting a camera's lens or mirror, a more common technique used in consumer cameras that have optical image stabilization. Because the process is electronic, the technology can be distributed to each cell of the CCD array, allowing for much more granular adjustments to localized atmospheric turbulence. The result is an image that is sharper than what a ground-based observatory could produce.

The mosaic structure of the CCD camera also leads to a more reliable system and less expensive manufacturing costs, Burke says. "The chip could not possibly be made to that size, so we are forced to break the camera down into tiles," he says.

Each Pan-STARRS camera consists of an eight-by-eight array of devices, each containing an eight-by-eight array of CCD cells. The size of each cell--about six millimeters on a side--is determined by a sweet spot...

Space experts call for asteroid action plan

From: http://www.msnbc.msn.com/id/27910044/
Space experts call for asteroid action plan
Time needed to deflect asteroids, evacuate people living in impact zone
updated 11:55 a.m. ET, Tues., Nov. 25, 2008
VIENNA, Austria - Space experts are urging the United Nations to devise a plan that allows for quick action against asteroids. Rusty Schweickart, a former U.S. astronaut, says such a plan would save the time needed to deflect asteroids or evacuate people living in a possible impact zone. He says researchers will increasingly be able to predict collisions and that, for the first time in history, technical capabilities exist to prevent them. Schweickart and other experts spoke to reporters Tuesday after presenting a report on the matter to U.N. officials in Vienna.

24 November 2008

All-Sky Camera Network

One method by which meteors can be observed & tracked.

Did Asteroid Cause Ancient N.Y. Tsunami?

Long before New York City was the Big Apple, or even New Amsterdam, a giant tsunami crashed ashore.
It was 2,300 years ago. The Palisades that frame the Hudson River were whisper-quiet, the sandy beaches of Long Island and New Jersey empty, and Manhattan was still just an unbroken sylvan carpet.
Then came the mammoth wave, roaring into the serenity. No one knows for sure what caused it, but new clues found in the Hudson's silt suggest an asteroid 100 meters (330 feet) in diameter slammed into the Atlantic Ocean nearby.
While sifting through samples, Katherine Cagen of Harvard University and a team of researchers found carbon spherules -- perfectly round particles that form in the extreme pressures of an impact.
"But the main thing that closes the deal is that we looked in the spherules and found nano-diamonds," said Dallas Abbott of Columbia University, a co-author on the work. "These have only been found in impact ejecta or in meteorites."
The team found grains of several shocked minerals in the sediments as well, but the discovery remains controversial.
"To get a wave 2.5 meters high that far up the Hudson, you need a wave 20 meters high at Manhattan," said Steven Ward of the University of California, Santa Cruz. "It would've gone several hundred meters inland on Long Island; you should see evidence of this thing all over the place."
Bunch of terrific Asteroid/Tidal Wave Sims here: http://es.ucsc.edu/~ward/

$10,000 to anyone who can locate and give him the first one-kilogram chunk

This meteor was thought to generate only about 1/3 KT (from 10% luminous efficiency based on measured irradiance), which would make it significantly smaller (less than half) than 2008TC3 which impacted the atmosphere over Sudan (see earlier posts). The Canadians are apparently feverishly working to estimate the fall area and recover fragments before the first snow.

This particular meteor was thought to weigh about one to seven tonnes before it entered the Earth's atmosphere, and was five times as bright as a full moon.

He said the people with the best chance of finding pieces are the ones who heard the sonic boom made by the falling meteorite chunks.
"If you hear that, then you're probably within 30 kilometres of it."

22 November 2008

Amazing Video of Meteor over Canada

About 1730 yesterday, in Edmonton, Canada:
From: http://www.google.com/hostednews/canadianpress/article/ALeqM5jU4E6gEY14ICcUMiwnqPkveUsF3w
"I just happened to look outside facing east," he said. "All of a sudden I saw this big flash coming down and I thought somebody was playing tricks on me, like fireworks behind the house or something.
"Just before that I heard a boom. I didn't know if it was a tree against the house. It was green and blue and it was coming down pretty fast."
Gobeil said the light display eventually turned orange, yellow and red and lasted 10 seconds.
"I was waiting for it to explode," he said. "It looked similar to when we watch (news reports) in Afghanistan. When I didn't see that, I said, 'well, that's something from outer space.' I'm sure it landed way out in Winnipeg or something."
"It's exciting - both scary and really nice."

10 November 2008

Future Channel Posts new video on Space Solar Power

A new video for math and science classrooms:

To consider the space solar power concept requires an understanding of science, technology, engineering, math, energy, policy, environmental factors, and more. Space solar power is an engineering project on a scale that rivals the greatest in history. Students need to be informed and able to participate in the conversation.

Image of TC3 in Sky

A month after asteroid 2008 TC3 hit the Earth's atmosphere, the first ground-based image of the event has surfaced on the Internet. Admittedly, it's not the fireball everyone has been waiting to see, but it is visual evidence that something hit us above Sudan on October 7th. The image above was taken from a frame of video that was being recorded by Mr. Mohamed Elhassan Abdelatif Mahir in the dawn following the asteroid impact with the atmosphere. The smoky feature is the remnant of the fireball as the 3 meter-wide asteroid blasted through the upper atmosphere, eventually exploding. The long-lasting persistent train is seen hanging in the air, high altitude winds causing it to twist in the morning sunlight.
We may not have a dazzling fireball re-entry video of 2008 TC3, but this striking image provides the first ground-based evidence of the direct hit, and may help refine the search for any meteorites from the disintegrated asteroid…