Comets


Telescope

Korean Discovers Comet for First Time

Yi Dae-am
© UnknownYi Dae-am,
Head of Yongwol Insectarium
An amateur stargazer has discovered a new comet, becoming the first South Korean to do so, science authorities said Wednesday.

Yi Dae-am, who heads the Yongwol Insectarium in Gangwon Province, found the comet, named as Yi-SWAN C/2009 F6, using a 90 millimeter telescope and a digital camera on March 26.

Yi discovered the comet almost simultaneously with American astronomer Robert Mason, who found the comet in pictures taken from the SWAN (Solar Wind ANisotropies) solar observation instrument on the Solar Heliospheric Observatory spacecraft from March 29 to April 4.

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Swift's Comet Tally

Image
© NASAMontage of comets Lulin, Tuttle, and SW3
Swift's primary job is to quickly alert astronomers about new gamma-ray bursts - powerful explosions from distant dying stars. "But Swift's rapid response and flexibility allow us to perform other science while the spacecraft is waiting for gamma-ray bursts to occur," said presenter Geronimo Villanueva, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

From its orbital perch, Swift can view targets using ultraviolet wavelengths, visible light, and X rays -- and it's the only observatory that sees them at the same time. Between bursts, astronomers task Swift to survey the entire sky at X-ray wavelengths, monitor exploding stars, image galaxies, and study comets.

Comets are clumps of frozen gases mixed with dust sometimes called "dirty snowballs." These icy bodies cast off gas and dust whenever they venture near the sun. Most recently, Swift observed Comet Lulin as part of a study led by Jenny Carter at the University of Leicester, U.K. Lulin was faintly visible to the naked eye when it passed 38 million miles from Earth --- or about 160 times farther than the moon - in late February.

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A comet may have caused widespread large mammal extinctions 12,900 years ago

The big bang theory's back. But this time the theory doesn't involve the cosmos, just a comet.

Some scientists hypothesize that relatively recently in our geological history a comet collided with Earth. And they're not talking about the collision 65 million years ago that did in the dinosaurs. They're talking about a collision 12,900 years ago, which did away with woolly mammoths, saber-tooth tigers and giant sloths, among some three dozen large mammals.

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Comet Chemistry Explains Tunguska event

A better understanding of the chemistry of comets may finally explain the 1908 exposion over an isolated part of Russia.

Tunguska
© Unknown
On 30 June 1908, a bolide streaked across the skies above Lake Baikal near the border of Russia and Mongolia. Seconds later, a huge explosion above the taiga some 600 kilometres to the northeast flattened an area of forest the size of Luxembourg and went on to scorch trees for hundreds of kilometres around.

The detonation took place in a more or less uninhabited part of Russia called Tunguska but the explosion lit up skies across the northern hemisphere for three nights, interfered with the Earth's magnetic field and triggered strong seismic and acoustic waves that shook the entire planet.

Despite a century of study, many aspects of the Tunguska event are still unexplained. For example, the explosion released more energy than a thousand Hiroshima-type atom bombs and yet left no crater. A similar-sized object is thought to have hit North America some 12 000 years ago, triggering the megafaunal extinction and widespread cooling. And yet the Tunguska event seems to have left our climate intact.

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Comet impacts can destroy stellar systems

Many scientists believe the dinosaurs were snuffed out by comet collision

Some stars have a high level of comet activity around them, and that could spell doom for any life trying to take root on any local planets. Ongoing research is trying to determine what fraction of stellar systems may be uninhabitable due to comet impacts.

Many of our own solar system's comets are found in the Kuiper Belt, a debris-filled disk that extends from Neptune's orbit (30 AU) out to almost twice that distance. Other stars have been shown to have similar debris disks.

"The debris is dust and larger fragments produced by the break-up of comets or asteroids as they collide amongst themselves," says Jane Greaves of the University of St. Andrews in Scotland.

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Space Debris, Comets and Asteroids Threaten Earth

Impact
© Unknown
Humankind has created a major problem: space debris, now threatening long-term space travel. So much space junk has accumulated that the international community must take urgent action to prevent major accidents at high altitude and on Earth.

Space debris denote man-made objects in orbit around Earth that no longer serve any useful purpose but which endanger operational satellites, primarily manned spacecraft. In some cases, space junk may threaten Earth during reentry because some fragments do not burn up completely and can hit houses, industrial facilities and transport networks.

Right now, 40 million fragments of space debris weighing several thousand metric tons circle Earth. In mid-February, the United Nations Office for Outer Space Affairs (UNOOSA) reaffirmed the importance of guiding principles to prevent the formation of space debris for all nations.

On December 17, 2007, the UN General Assembly passed its Resolution 62/101 stipulating recommendations on enhancing the practice of states and international intergovernmental organizations in registering space objects.

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UFO's in the Sky? Probably a Comet

Multiple people in Waukesha County called WTMJ reporters and the Waukesha Sheriff's Department, reporting unusual lights in the evening sky.

Could it have been something from another world, a UFO?

"Somebody saw something," said Waukesha County Sheriff's Captain Karen Ruff.

"I don't know if it was just a planet, the sky, the clouds, the stars or what it was. There was something out there.

"We do let our officers know, because it could be a plane or a helicopter in trouble. We do have them go out and look. Nobody saw anything, so we don't quite know what it was."

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Comet's Heart May Have Struck Earth

Image
© Unknown

Bright lights that suddenly streak across the night sky with an accompanying boom tend to elicit a flurry of phone calls to local police departments.

These rare events aren't typically wayward missiles, or satellite debris (as was thought when one such streak recently lit up the skies over Texas), or alien invasions. But they do come from outer space.

Scientists aptly call the objects fireballs because they are the brightest meteors, or "shooting stars," that fall to Earth.

A fireball as bright as the full moon raced across the Spanish skies on July 11, 2008, and was tracked by the Spanish Fireball Network (SPMN). Researchers used the tracking data to trace the path of the comet backwards through the sky and space; they think the boulder may be a chunk of a comet that broke up nearly 90 years ago. Their conclusions are detailed in the Feb. 11 online issue of the journal Monthly Notices of the Royal Astronomical Society.

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NASA's Swift spies Comet Lulin

Lulin jan 28 09
© NASA/Swift/Univ. of Leicester/Bodewits et al.This image of Comet Lulin taken Jan. 28 merges data acquired by Swift's Ultraviolet/Optical Telescope (blue and green) and X-Ray Telescope (red). At the time of the observation, the comet was 99.5 million miles from Earth and 115.3 million miles from the sun.

While waiting for high-energy outbursts and cosmic explosions, NASA's Swift Gamma-ray Explorer satellite is monitoring Comet Lulin as it closes on Earth. For the first time, astronomers are seeing simultaneous ultraviolet and X-ray images of a comet.

"We won't be able to send a space probe to Comet Lulin, but Swift is giving us some of the information we would get from just such a mission," said Jenny Carter, at the University of Leicester, U.K., who is leading the study.

"The comet is releasing a great amount of gas, which makes it an ideal target for X-ray observations," said Andrew Read, also at Leicester.

A comet is a clump of frozen gases mixed with dust. These "dirty snowballs" cast off gas and dust whenever they venture near the sun. Comet Lulin, which is formally known as C/2007 N3, was discovered last year by astronomers at Taiwan's Lulin Observatory. The comet is now faintly visible from a dark site. Lulin will pass closest to Earth -- 38 million miles, or about 160 times farther than the moon -- late on the evening of Feb. 23 for North America.

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Lulin: Comet Making One-Time Only Visit Next Week

Comet Lulin
© Jack Newton

An odd, greenish backward-flying comet is zipping by Earth this month, as it takes its only trip toward the sun from the farthest edges of the solar system. The comet is called Lulin, and there's a chance it can be seen with the naked eye - far from city lights, astronomers say. But you'll most likely need a telescope, or at least binoculars, to spot it.

The best opportunity is just before dawn one-third of the way up the southern sky. It should be near Saturn and two bright stars, Spica and Regula.