Comets


Meteor

Office worker stares off into space... and is the only man on Earth to see exploding comet

Image
© UnknownCaught on camera: Siding Spring comet breaking up 100 million miles from Earth. The chunk that can be seen behind the comet is said to be the size of Mount Everest

An amateur stargazer has captured the moment a comet exploded in space - an event missed by the world's professional astronomers.

Musical instrument designer Nick Howes, 40, used the internet to access an online telescope as he sat at his desk in his office.

Mr Howes, of Cherhill near Calne, Wilts, logged on to a telescope in Hawaii and began staring into deep space. But he spotted a massive comet breaking up and was able to use the telescope to take photos.

Nick, who works for Yamaha, actually captured the moment the comet exploded, blowing a chunk the size of Mount Everest off one side.

He was the only person in the world to witness the dramatic event - with even American astronomers completely missing the opportunity.

Meteor

Comet-Kaze Strikes The Sun

At first glance it looks like aliens are using the sun for target practice. A string of bullet-shaped streaks of light appear to be shooting straight toward the sun.

These are proverbial snowballs in Hell, plunging 300 miles per second toward a fiery end in the sun's atmosphere.


Meteor

Bright Sun-Grazing Comet

Image
© SOHO
A newly-discovered comet is plunging toward the sun and probably will not survive. The encounter is too close to the sun for human eyes to see, but the Solar and Heliospheric Observatory (SOHO) is able to monitor the action using an opaque disk to block the sun's glare.

The doomed comet is probably a member of the Kreutz sungrazer family. Named after a 19th century German astronomer who studied them in detail, Kreutz sungrazers are fragments from the breakup of a giant comet at least 2000 years ago. Several of these fragments pass by the sun and disintegrate every day. Most are too small to see but occasionally a big fragment--like this one--attracts attention.

Click here to launch a 12-hour time-lapse animation

Igloo

Ice Age Cometh: Coldest Irish winter since 1963

Image
© UnknownView of Dublin from the Dublin Mountains, February 7th
Ireland suffered its coldest winter in almost five decades as the country shivered in the big freeze, it was revealed.

Met Eireann said temperatures were around two degrees lower than average during the season, making it the coldest winter recorded since 1963.

Arctic conditions experienced at the end of last year continued through January and February, with widespread spells of frost, sleet and snow.

Temperatures plummeted to below minus 10C in some places, with minus 16.3C recorded at Mount Juliet, Co Kilkenny, on January 7.

Meteor

First measurement of the age of cometary material

Image
© LLNLSecondary electron image of the Coki section analyzed in this study showing mineral shards surrounded by compressed aerogel.
Livermore, California - Though comets are thought to be some of the oldest, most primitive bodies in the solar system, new research on comet Wild 2 indicates that inner solar system material was transported to the comet-forming region at least 1.7 million years after the formation of the oldest solar system solids.

The research by Lawrence Livermore National Laboratory scientists and colleagues provides the first constraint on the age of cometary material from a known comet. The findings are published in the Feb. 25 edition of Science Express.

The NASA Stardust mission to comet Wild 2, which launched in 1999, was designed around the premise that comets preserve pristine remnants of materials that helped form the solar system. In 2006, Stardust returned with the first samples from a comet.

Satellite

WISE Spies Its First Comet

Image
© NASA/JPL-Caltech/UCLAThe red smudge at the center of this picture is the first comet discovered by NASA's Wide-Field Infrared Survey Explorer, or WISE.
The Wide-field Infrared Survey Explorer or WISE is living up to expectations, as it now has discovered its first comet, shortly after finding its first asteroid. The spacecraft, just launched on Dec. 14, 2009 and first spotted the comet on January 22, 2010. WISE is expected to find millions of other objects during its ongoing survey of the whole sky in infrared light. Officially named "P/2010 B2 (WISE)," the comet is a dusty mass of ice more than 2 kilometers (1.2 miles) in diameter.

Comet and asteroid hunter Robert Holmes, who we have written about previously on Universe Today (whose Astronomical Research Observatory and Killer Asteroid Project in Illinois is not far from where I live) made the first ground-based confirmation of WISE's comet discovery, with his home-built 0.81-meter telescope. Many large observatories attempted to confirm this discovery more than 7 days earlier including the Faulkes 2.0m telescope in Hawaii, without success. And due to poor weather, Holmes had to wait several days to get a look at the WISE comet himself. Holmes produces images for educational and public outreach programs like the International Astronomical Search Collaboration (IASC), which gives students and teachers the opportunity to make observations and discoveries, and a teacher actually assisted in the confirmation of this new comet.

Meteor

Dark Ages: Did a comet impact cause global catastrophe around 500 A.D.?

Image
© Detlev van Ravenswaay, Astrofoto, Peter Arnold Images, PhotolibraryAn asteroid hurtles toward Earth in an artist's rendering.
Double impact may have caused tsunami, global cooling

Pieces of a giant asteroid or comet that broke apart over Earth may have crashed off Australia about 1,500 years ago, says a scientist who has found evidence of the possible impact craters.

Satellite measurements of the Gulf of Carpentaria (see map) revealed tiny changes in sea level that are signs of impact craters on the seabed below, according to new research by marine geophysicist Dallas Abbott.

Based on the satellite data, one crater should be about 11 miles (18 kilometers) wide, while the other should be 7.4 miles (12 kilometers) wide.

For years Abbott, of Columbia University's Lamont-Doherty Earth Observatory, has argued that V-shaped sand dunes along the gulf coast are evidence of a tsunami triggered by an impact.

"These dunes are like arrows that point toward their source," Abbott said. In this case, the dunes converge on a single point in the gulf - the same spot where Abbott found the two sea-surface depressions.

The new work is the latest among several clues linking a major impact event to an episode of global cooling that affected crop harvests from A.D. 536 to 545, Abbott contends.

According to the theory, material thrown high into the atmosphere by the Carpentaria strike probably triggered the cooling, which has been pinpointed in tree-ring data from Asia and Europe.

What's more, around the same time the Roman Empire was falling apart in Europe, Aborigines in Australia may have witnessed and recorded the double impact, she said.

Comment: For an in-depth study, read Laura Knight-Jadczyk's review of New Light on the Black Death: The Cosmic Connection.


Meteor

Comet storm split destiny of Jupiter's twin moons

Image
© NASA/JPLComet strikes may have warmed Ganymede enough for its ice and rock to fully separate
Heavy pummelling by icy comets could explain why Jupiter's two biggest moons - apparently close kin - look so different inside.

At first glance, Ganymede and Callisto are virtually twins. The colossal moons are similar in size and mass, and are a roughly 50:50 mixture of ice and rock.

However, visits by the Galileo spacecraft beginning in 1996 tell a different story. Ganymede's interior boasts a solid rock core surrounded by a thick layer of ice, while ice and rock are still mingled in parts of Callisto. That suggests Callisto was never warm enough for its ice to melt and allow all of its rock to fall to the centre and form a core.

Blackbox

Mystery Object Behaves Both Like a Comet and Asteroid

Image
© Spacewatch/U of Arizona
Something awfully curious is happening 250 million miles away in the asteroid belt. Nothing quite like it has ever been seen before.

There's a newly discovered object that superficially looks like a comet but lives among the asteroids.

The distinction? Comets swoop along elliptical orbits close in to the sun and grow long gaseous and dusty tails as ices sublimate off their solid nucleus and release dust. But asteroids are mostly in more circular orbits and are not normally expected to be as volatile as comets.

The puzzling object was discovered on January 6 by the Lincoln Near-Earth Asteroid Research (LINEAR) sky survey. The object appears to be in an orbit inside the main asteroid belt -- not a place where comets dwell. A member of the asteroid belt has never before been seen erupting a "tail."

Meteor

New Comet Found, Vaporized

Like a modern-day Icarus, this newfound comet learned the hard way what happens when you fly too close to the sun.