A comet may have hit the planet Neptune about two centuries ago. This is indicated by the distribution of carbon monoxide in the atmosphere of the gas giant that researchers -- among them scientists from the French obser-vatory LESIA in Paris, from the Max Planck Institute for Solar System Re-search (MPS) in Katlenburg-Lindau (Germany) and from the Max Planck Insti-tute for Extraterrestrial Physics in Garching (Germany) -- have now studied. The scientists analyzed data taken by the research satellite Herschel, that has been orbiting the Sun in a distance of approximately 1.5 million kilometers since May 2009. The research is published in Astronomy & Astrophysics (July 16, 2010).

When the comet Shoemaker-Levy 9 hit Jupiter sixteen years ago, scientists all over the world were prepared: instruments on board the space probes Voyager 2, Galileo and Ulysses documented every detail of this rare incident. Today, this data helps scientists detect cometary impacts that happened many, many years ago. The "dusty snowballs" leave traces in the atmosphere of the gas giants: water, carbon dioxide, carbon monoxide, hydrocyanic acid, and carbon sulfide. These molecules can be detected in the radiation the planet radiates into space.

In February 2010 scientists from Max Planck Institute for Solar System Research discovered strong evidence for a cometary impact on Saturn about 230 years ago (see Astronomy and Astrophysics, Volume 510, February 2010). Now new measurements performed by the instrument PACS (Photodetector Array Camera and Spectrometer) on board the Herschel space observatory indicate that Neptune experienced a similar event. For the first time, PACS allows researchers to analyze the long-wave infrared radiation of Neptune.

They're called catastrophists, a group of British scientists who question many of the aspects of Darwinian evolution and argue that life on Earth and the geology of the planet have been constantly reshaped by asteroid strikes and other external shocks.

The latest sally from the catastrophist camp comes from the astronomer and mathematician Chandra Wickramasinghe, who told a scientific congress in California in July that he had found microbes in air samples scooped up by a balloon flying 25 miles (about 40 kilometers) above the Earth's surface.

Mr. Wickramasinghe, director of the department of Astrobiology at Cardiff University in Wales, said it was the first positive identification of extraterrestrial microbial life outside the atmosphere. The fact that a major British university has set up a department dedicated to a theory still regarded with much skepticism and hostility in the academic community is one indication of how accepted catastrophist ideas have become in British science.

Sodom and Gomorrah may have been destroyed by debris from a comet, startling new archaeological and astronomical research suggests. Another bombardment from space may have brought on the Dark Ages.

The research, to be presented to a conference at Cambridge University this summer, provides dramatic evidence for an extraterrestrial cause for the wholesale collapse of several civilisations around 2200BC.

The conference, on natural catastrophes during Bronze Age civilisations, will bring together astronomers, archaeologists, geologists and other scientists to try to find an explanation for the near-simultaneous fall of the Old Kingdom of ancient Egypt, the Sumerian civilisation in Mesopotamia and the Harrapin Civilisation of the Indus Valley. In all, some 40 cities are thought to have disappeared, in a series of catastrophes.

Astronomers calculate that the Earth is bombarded by a particular dense storm of meteorites over a couple of centuries every 2,500 years - the last two blitzes would have occurred around 2200-2000BC and 400-600AD.

The Global Catastrophic Risks conference started yesterday morning and death by asteroids, comets and gamma ray bursts was on the agenda as experts discussed the statistical likelihood of these types of global catastrophes.

First up at the conference on Global Catastrophic Risks was the topic of asteroids, with David Morrison who is a NASA senior scientist. He spoke about the threat of a catastrophic asteroid strike and the Spaceguard Survey.

It is NASA's responsibility since 1998, to monitor the skies and detect near Earth asteroids that are larger than 1 kilometer in size, which is the size that, if it hit Earth, could end civilization.

Morrison stated that 80 percent of the near Earth asteroids that are 1 kilometer or larger have been identified and that he could assure those gathered at the conference that "We are not going the way of the dinosaurs." He also says the Spaceguard Survey has not turned up any near Earth asteroids as large as the one that is believed to have wiped out the dinosaurs.

The sun has just experienced a storm - not of explosive flares and hot plasma, but of icy comets.

"The storm began on Dec 13th and ended on the 22nd," says Karl Battams of the Naval Research Lab in Washington, DC. "During that time, the Solar and Heliospheric Observatory (SOHO) detected 25 comets diving into the sun. It was crazy!"

Sundiving comets - a.k.a. "sungrazers" - are nothing new. SOHO typically sees one every few days, plunging inward and disintegrating as solar heat sublimes its volatile ices. "But 25 comets in just ten days, that's unprecedented," says Battams.


"The comets were 10-meter class objects, about the size of a room or a house," notes Matthew Knight of the Lowell Observatory in Flagstaff, Arizona. "As comets go, these are considered small."

SOHO excels at this kind of work. The spacecraft's coronagraph uses an opaque disk to block the glare of the sun like an artificial eclipse, revealing faint objects that no Earth-bound telescope could possibly see. Every day, amateur astronomers from around the world scrutinize the images in search of new comets. Since SOHO was launched in 1996, more than 2000 comets have been found in this way, an all-time record for any astronomer or space mission.

Battams and Knight think the comet-storm of Dec. 2010 might herald a much bigger sungrazer to come, something people could see with the naked eye, perhaps even during the day.

"It's just a matter of time," says Battams. "We know there are some big ones out there."

July 7, 2000 -- In October 1965 comet Ikeya-Seki swooped past the Sun barely 450 thousand kilometers above our star's bubbling, fiery surface. Gas and dust exploded away from the comet's core as fierce solar radiation vaporized the icy nucleus. Most comets wouldn't survive passing as close to the Sun as the Moon is to the Earth, but Ikeya-Seki literally came through with flying colors. When the comet emerged from perihelion (closest approach to the Sun) it was so bright that observers on the street with very clear skies could see it during broad daylight if the Sun was hidden behind a house or even an outstretched hand.

"In Japan (where observers spied the comet 1/2 degree from the Sun) it was described as 10 times brighter than the Full Moon," recounted Brian Marsden of the Harvard Center for Astrophysics in the December 1965 issue of Sky & Telescope. "At Kitt Peak National Observatory in Arizona, Stephen Maran observed the comet with binoculars from within the shadow of a black disk erected to hide the Sun. '[It was] the most splendid thing I have ever seen,' he noted."

Ikeya-Seki, a.k.a. "The Great Comet of 1965", is a member of the family of comets called Kreutz sungrazers (after the nineteenth-century German astronomer who studied them in some detail). These ill-fated visitors to the inner solar system have been seen to pass less than 50,000 km above the Sun's photosphere. Most never make it past perihelion -- they are completely obliterated. But the few that do, like Ikeya-Seki, can be very bright.

In the last 10 days astronomers have counted at least 25 comets on the NASA SOHO Spacecraft, plunging into the Sun. It could mean a larger one ahead.

These comets could be part of a larger comet, according to astronomers. The comet may come without notice, much like the cosmic visitor named Comet Ikeya-Seki in 1965, which was seen in broad daylight and came without warning.

One candidate would be the newly discovered Comet 2010 X1 Elenin, which comes very close to our planet in the Fall of 2011. The comet will be so bright you can see it with the unaided eye even in a small city.

There have been several reports, from Florida to Oklahoma, of people seeing a meteor streaking across the southern sky Tuesday night.

The sighting took place around 9 p.m. It is being described as a fireball that resulted in a bright flash. In pictures it looks like a greenish-blue streak, almost like lighting. It only lasted a second.

However, many pictures have also been identified as fakes so no one is 100 percent sure what the occurrence is.

According to astronomers, if it was a meteor it most likely contained copper which is why it gave off a greenish glow. It was also reported traveling southeast to northwest.

"Based on everyone's description instead of coming down it sounds like it came more across which gives it more time to burn up so more than likely it burned up in the atmosphere," said Stephen Meeks, amateur astronomer.

If it was a meteor it was a pretty rare sight, those types of meteors only occur five or six times a year in the United States, according to meteor expert Steve Arnold.

Galveston - Some island residents, firefighters, police and city hall officials heard a loud boom Wednesday, but the source of the noise remains a mystery.

Galveston Fire Chief Jeff Smith heard the explosion shortly before noon as he traveled on 12th Street.

City spokeswoman Alicia Cahill was at city hall, and police spokesman Lt. Jeff Heyse was at the police station when they heard the noise.

"We had several calls come into dispatch, and we sent an engine company out to investigate," Smith said.

One person called from 42nd Street, and the noise was heard as far west as 61st Street, Smith said.

"I was actually coming up on 12th street, and it was clearly a very loud noise," Smith said.

Firefighters found no fire and documented no sign of an explosion.

The sun has just experienced a storm - not of explosive flares and hot plasma, but of icy comets.

"The storm began on Dec 13th and ended on the 22nd," says Karl Battams of the Naval Research Lab in Washington, DC. "During that time, the Solar and Heliospheric Observatory (SOHO) detected 25 comets diving into the sun. It was crazy!"

Sundiving comets - a.k.a. "sungrazers" - are nothing new. SOHO typically sees one every few days, plunging inward and disintegrating as solar heat sublimes its volatile ices. "But 25 comets in just ten days, that's unprecedented," says Battams.

"The comets were 10-meter class objects, about the size of a room or a house," notes Matthew Knight of the Lowell Observatory in Flagstaff, Arizona. "As comets go, these are considered small."