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Fri, 30 Oct 2020
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Comets

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Comet Holmes and the case of the Disappearing Tail

But what's a Comet, anyway?

©REUTERS/NASA, ESA, and H. Weaver/The Johns Hopkins University Applied Physics Laboratory/Handout
A Hubble image (R), taken November 4, 2007, shows the heart of Comet 17P/Holmes. The central portion of the image has been specially processed to highlight variations in the dust distribution near the nucleus. About twice as much dust lies along the east-west direction (the horizontal direction) as along the north-south direction (the vertical direction), giving the comet a "bow tie" appearance. The composite color image at left, taken on November 1, 2007, by an amateur astronomer shows the complex structure of the entire coma, consisting of concentric shells of dust and a faint tail emanating from the comet's right side. The normally sedate Comet Holmes made a bright splash in the sky about two weeks ago, unexpectedly becoming a million times brighter than normal overnight and causing a stir among astronomers.

Comment: Enjoy our latest Forum's Topic:

Speculations about the Comet 17P/Holmes


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Astronomers unravel a mystery of the Dark Ages: Research blames comet for 6th-century 'nuclear winter'

Scientists at Cardiff University, UK, believe they have discovered the cause of crop failures and summer frosts some 1,500 years ago - a comet colliding with Earth.

The team has been studying evidence from tree rings, which suggests that the Earth underwent a series of very cold summers around 536-540 AD, indicating an effect rather like a nuclear winter.

The scientists in the School of Physics and Astronomy believe this was caused by a comet hitting the earth and exploding in the upper atmosphere. The debris from this giant explosion was such that it enveloped the earth in soot and ash, blocking out the sunlight and causing the very cold weather.

This effect is known as a plume and is similar to that which was seen when comet Shoemaker-Levy-9 hit Jupiter in 1995.

Historical references from this period - known as the Dark Ages - are sparse, but what records there are, tell of crop failures and summer frosts.

Telescope

Comet Holmes' display captivates stargazers

The normally sedate Comet Holmes made a bright splash in the sky about two weeks ago, unexpectedly becoming a million times brighter than normal overnight and causing a stir among astronomers.

©REUTERS/NASA, ESA, and H. Weaver/The Johns Hopkins University Applied Physics Laboratory/Handout
A Hubble image (R), taken November 4, 2007, shows the heart of Comet 17P/Holmes. The central portion of the image has been specially processed to highlight variations in the dust distribution near the nucleus. About twice as much dust lies along the east-west direction (the horizontal direction) as along the north-south direction (the vertical direction), giving the comet a "bow tie" appearance. The composite color image at left, taken on November 1, 2007, by an amateur astronomer shows the complex structure of the entire coma, consisting of concentric shells of dust and a faint tail emanating from the comet's right side.

Ambulance

Look Up! Comet Holmes Bigger Than The Sun

Formerly, the Sun was the largest object in the Solar System. Now, comet 17P/Holmes holds that distinction.

Comment: The same image is available from the University of Hawaii as a 300 dpi tif file.


Telescope

Comets: The Loose Thread

Spacecraft have now visited four comets. What they found contradicts what was expected and falsifies accepted comet theory. But that theory is woven with every other astronomical theory into a cosmology that defines the universe as we know it. The fall of comet theory will inevitably bring us a new and different universe.

©NASA/JPL/Malin Space Science Systems
Comet Wild 2 is shown in close-up above. Beside it is a microscopic view of an EDM (electrical discharge machined) surface. Note the flat-floored depressions with steep scalloped walls and terracing. The small white spots on the comet can then be reasonably identified as the active cathode arcs that produce the cometary jets.

Telescope

"Holming" in on a really bright comet

Stargazers will be in seventh heaven when one of the most spectacular sights in the night sky becomes visible above Paisley.

And, to make the outlook even brighter, Buddies won't even need binoculars or telescopes to identify the celestial wanderer.

They'll see it all with the naked eye.

©Sky and Telescope

Star

Giant comet awes UH scientists



©University of Hawaii
A comparison of Comet Holmes, the sun and Saturn (inset) is shown in this image from the University of Hawaii.

Once a faint, obscure comet, 17P/Holmes has eclipsed the sun as the largest object in the solar system and it's still growing, Hawaii astronomers say.

The spectacular comet has dazzled astronomers since it exploded Oct. 24 from a tiny nucleus of ice and rock about 2.2 miles in diameter.

Star

Is Comet 17P Holmes losing its tail?

"Is Comet 17P/Holmes losing its tail?" asks Italian astronomer Paolo Berardi. "Last night I recorded an image showing a big disconnection event that was not present on Nov 8th."

©Paolo Berardi

Telescope

Did a collision cause comet's mysterious outburst?

Comet 17P/Holmes has certainly given sky-watchers - backyard and professional astronomers alike - a thrilling chance to see a cometary outburst on a grand scale. After we posted my story about on-going speculation about what could have caused this outburst (and the one 115 years ago), many readers posted comments related to two questions: Could this have been triggered by a collision with an object in the main asteroid belt? And why can't we see more of a tail on this comet?

©Pic du Midi Observatory/Francois Colas/Jean Lecacheux/Boris Baillard
Holmes

Star

Comet Draws Scientific, Amateur Interest



©Unknown
Comet Holmes is seen among the stars of the constellation Perseus in the North-Eastern sky.

KNOXVILLE, Tenn. - A comet that unexpectedly brightened in the last couple of weeks and is now visible to the naked eye is attracting professional and amateur interest.