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Sun, 28 Feb 2021
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NASA's Spitzer tries to unravel mysterious comet explosion

Washington: NASA's Spitzer Space Telescope has deeply observed comet Holmes to find out why it suddenly exploded in 2007.

Observations taken of the comet by Spitzer deepen the mystery, showing oddly behaving streamers in the shell of dust surrounding the nucleus of the comet.
The data also offer a rare look at the material liberated from within comet Holmes' nucleus, and confirm previous findings from NASA''s Stardust and Deep Impact missions.

"The data we got from Spitzer do not look like anything we typically see when looking at comets," said Bill Reach of NASA''s Spitzer Science Center at the California Institute of Technology, Pasadena, California.

"The comet Holmes explosion gave us a rare glimpse at the inside of a comet nucleus," he added.

Every six years, comet 17P/Holmes speeds away from Jupiter and heads inward toward the sun, traveling the same route typically without incident.


Italian astronomer finds new comet

ROME -- An Italian astronomer said he has discovered a new comet --the fifth one he has found in less than a year.

Andrea Boattini, who is currently working at Mount Lemmon Infrared Observatory in Arizona, said he spotted the comet while scanning near-Earth objects, the Italian news service ANSA reported Wednesday.

The comet, technically named P/2008 T1, will also be known as Boattini T1. The astronomer said it was easy to spot because of its unusual blaze and fan-like tail.


New comet discovered where comets aren't usually found

Calgary - Astronomer Rob Cardinal didn't expect the time he spent installing new software at the University of Calgary's Baker-Nunn telescope earlier this month to change his life.

But days later, his computer was telling him there had been some unusual movement through the telescope - motion that Mr. Cardinal hadn't detected while gazing through it.

But after some sleepless nights peering through cloud cover and finally spying what he'd missed, Mr. Cardinal is now the confirmed finder of C2008 T2, a never-before-identified comet travelling through the solar system.

Or, as it will also be known, Comet Cardinal.


An Inside Look at Comet Holmes

The astronomy world buzzed in the Fall of 2007 when Comet Holmes - a normally humdrum, run-of-the-mill comet - unexpectedly flared and erupted. Its coma of gas and dust expanded away from the comet, extending to a volume larger than the Sun. Professional and amateur astronomers around the world turned their telescopes toward the spectacular event. Everyone wanted to know why the comet had suddenly exploded.
Comet Holmes

The Hubble Space Telescope observed the comet, but provided few clues. And now, observations taken of the comet after the explosion by NASA's Spitzer Space Telescope deepen the mystery, showing oddly behaving streamers in the shell of dust surrounding the nucleus of the comet. The data also offer a rare look at the material liberated from within the nucleus. "The data we got from Spitzer do not look like anything we typically see when looking at comets," said Bill Reach of NASA's Spitzer Science Center at Caltech.


Re-Discovery of Long-Lost Comet Barnard 3

Those of you who have been following this blog for the past few weeks might read the title of this entry and sense a bit of deja vu. Even some of the details and the people involved are the same.

Nearly a month ago two Japanese amateur astronomers re-discovered Comet Giacobini which had been lost for 111 years. Now this weekend comes word that an object found by professional astronomer Andrea Boattini of the Catalina Sky Survey is also a re-discovery of a long-lost comet. After Boattini's find was officially announced, Maik Meyer of Limburg, Germany suggested that this comet was actually the same as a comet last seen on 1892 Dec 8.

Comet Barnard 3 was found by Edward Emerson Barnard of Nashville, TN on 1892 Oct 13. It was the first comet to be discovered with the then new technique of astro-photography. Before this, all comets were discovered by astronomers using only their eyes though many were found while looking through a telescope. The comet was as bright as 12th magnitude in 1892 which is much brighter than its current brightness of 17th magnitude. It is possible that similar to Comet Giacobini, this comet was experiencing an outburst in 1892 that made it brighter than usual. The reason it wasn't found during the next 116 years was because its usual brightness was too faint for most of the comet searchers. Today thanks to computers and CCD (digital) cameras, the current generation of comet and asteroid surveys can cover a good fraction of the sky to very faint brightnesses.

Since the comet was already credited to Boattini before the identification with Comet Barnard 3 was noticed, the comet will be officially named Comet Barnard-Boattini. Its official designation is Comet P/2008 T3 (Barnard-Boattini) though that will be shortened to 206P/Barnard-Boattini in a few weeks since it has been observed during 2 orbits.

Analysis published by the Central Bureau for Astronomical Telegrams on IAUC 8995 find that the comet's current orbit takes it from near the orbit of Jupiter (sun-comet distance of 5.33 AU) to just outside the Earth's orbit (sun-comet distance of 1.15 AU). Back in 1892 the comet only got as close to the Sun as 1.43 AU. The comet has made 20 orbits of the Sun between 1892 and 2008. It will make its closest approach to the Sun on Oct 24 and to the Earth around Oct 22 at a distance of 0.19 AU. Unfortunately the comet will not become bright enough for backyard observers.

Comet Barnard-Boattini was one of three new comets announced today. Comet C/2008 T2 (Cardinal) was found by Rob D. Cardinal of the University of Calgary. This long-period comet may become a nice binolcular comet next spring and summer. Rik Hill, also of the Catalina Sky Survey, found Comet C/2008 T4 (Hill) which is a faint short-period comet that will come no closer to the Sun than 2.45 AU.


Comet Dust Reveals Unexpected Mixing of Solar System

Chemical clues from a comet's halo are challenging common views about the history and evolution of the solar system and showing it may be more mixed-up than previously thought.

comet dust samples
© Noriko Kita
A team of researchers including Takayuki Ushikubo, Noriko Kita, and John Valley of the University of Wisconsin-Madison has identified unexpected chemical and isotope signatures that challenge existing views about the formation and history of the solar system.


BBC airs theory that comets and meteors hit every 1000 years

The BBC and the National Geographic Channel are making a documentary based on the controversial theories of a Wollongong academic, who claims that meteorites hit the earth every 1000 years.

Professor Ted Bryant
©Sylvia Liber
Professor Ted Bryant with the US film crew at Jones Beach.


Comets Throw Light On Solar System's Beginnings

A new picture of the composition of comets is emerging with the help of 21st century technology available at Diamond, the UK's national synchrotron light source, in Oxfordshire.

Comet Wild 2.

Scientists already know that comets played a significant role in ensuring that conditions were right for life on Earth. Most of the icy, small planetary bodies that otherwise became comets went into forming the gas giant planets in the outer Solar System but some were ejected from the vicinity of the largest planets. Of these, a fraction ended up in the inner Solar System bringing water and biogenic elements of interest to Earth. Without this cometary transport, life on Earth may never have had a chance to start.

Now, scientists from the Space Research Centre at the University of Leicester have, for the first time, brought samples of the Comet Wild-2 to Diamond. In doing so, using Diamond's microfocus spectroscopy capabilities - bright and powerful X-rays with a beam size equivalent to one 25th of a human hair - they have discovered that the old model of comets as dusty iceballs is not the whole picture.


Comets Disguised as Asteroids

An asteroid cruising through the solar system six years ago seemed just another silent ship sailing in the eternal darkness, until it flared up with the startling brightness of a comet's halo.


New Comet KV42 Explains Old Mystery


Halley's comet, which lights up Earth's sky every 75 years with its glowing tail, is a bit of a scientific mystery.

So far theories have been at a loss to explain how it acquired its extremely unusual backwards orbit, but the recent discovery of another odd comet orbiting farther out in the solar system may shed light on Halley's origins.

The newly-discovered comet 2008 KV42 circles the sun at a tilt of 104 degrees compared to the main plane in which most of the planets and asteroids travel. The newfound oddball also orbits in reverse compared to almost everything else. Scientists think it might represent an intermediate point between comets like Halley's and their progenitors in the far and totally uncharted reaches of the solar system.