Hubble: Comet Siding Spring
- orin stepanek
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Hubble: Comet Siding Spring
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ABOUT THIS IMAGE:
[Left]
This is a Hubble Space Telescope picture of comet C/2013 A1 Siding Spring as observed on March 11, 2014. At that time the comet was 353 million miles from Earth. The solid icy nucleus is too small to be resolved by Hubble, but it lies at the center of a dust cloud, called a coma, that is roughly 12,000 miles across in this image.
[Right]
When the glow of the coma is subtracted through image processing, which incorporates a smooth model of the coma's light distribution, Hubble resolves what appear to be two jets of dust coming off the nucleus in opposite directions. This means that only portions of the surface of the nucleus are presently active as they are warmed by sunlight, say researchers. These jets were first seen in Hubble pictures taken on Oct. 29, 2013. The feature should allow astronomers to measure the direction of the nucleus's pole, and hence, rotation axis.
Discovered in January 2013 by Robert H. McNaught at Siding Spring Observatory in New South Wales, Australia, the comet is falling toward the Sun along a roughly 1-million-year orbit and is now within the radius of Jupiter's orbit. The comet will make its closest approach to our Sun on Oct. 25, at a distance of 130 million miles — well outside Earth's orbit. On its inbound leg, Comet Siding Spring will pass within 84,000 miles of Mars on Oct. 19, 2014 (less than half the Moon's distance from Earth). The comet is not expected to become bright enough to be seen by the naked eye.
An earlier Hubble observation made on Jan. 21, 2014, caught the comet as Earth was crossing the comet's orbital plane. This special geometry allows astronomers to better determine the speed of the dust coming off the nucleus. "This is critical information that we need to determine how likely and how much the dust grains in the coma will impact Mars and Mars spacecraft," said Jian-Yang Li of the Planetary Science Institute in Tucson, Ariz.
This visible-light image was taken with Hubble's Wide Field Camera 3.
Object Name: C/2013 A1 Siding Spring
Image Type: Astronomical/Annotated
Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)
NEWS RELEASE IMAGES
ABOUT THIS IMAGE:
[Left]
This is a Hubble Space Telescope picture of comet C/2013 A1 Siding Spring as observed on March 11, 2014. At that time the comet was 353 million miles from Earth. The solid icy nucleus is too small to be resolved by Hubble, but it lies at the center of a dust cloud, called a coma, that is roughly 12,000 miles across in this image.
[Right]
When the glow of the coma is subtracted through image processing, which incorporates a smooth model of the coma's light distribution, Hubble resolves what appear to be two jets of dust coming off the nucleus in opposite directions. This means that only portions of the surface of the nucleus are presently active as they are warmed by sunlight, say researchers. These jets were first seen in Hubble pictures taken on Oct. 29, 2013. The feature should allow astronomers to measure the direction of the nucleus's pole, and hence, rotation axis.
Discovered in January 2013 by Robert H. McNaught at Siding Spring Observatory in New South Wales, Australia, the comet is falling toward the Sun along a roughly 1-million-year orbit and is now within the radius of Jupiter's orbit. The comet will make its closest approach to our Sun on Oct. 25, at a distance of 130 million miles — well outside Earth's orbit. On its inbound leg, Comet Siding Spring will pass within 84,000 miles of Mars on Oct. 19, 2014 (less than half the Moon's distance from Earth). The comet is not expected to become bright enough to be seen by the naked eye.
An earlier Hubble observation made on Jan. 21, 2014, caught the comet as Earth was crossing the comet's orbital plane. This special geometry allows astronomers to better determine the speed of the dust coming off the nucleus. "This is critical information that we need to determine how likely and how much the dust grains in the coma will impact Mars and Mars spacecraft," said Jian-Yang Li of the Planetary Science Institute in Tucson, Ariz.
This visible-light image was taken with Hubble's Wide Field Camera 3.
Object Name: C/2013 A1 Siding Spring
Image Type: Astronomical/Annotated
Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)
NEWS RELEASE IMAGES
Orin
Smile today; tomorrow's another day!
Smile today; tomorrow's another day!
- geckzilla
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Re: Comet Siding Spring
Where's the link to the original article, Orin?
Just call me "geck" because "zilla" is like a last name.
Re: Comet Siding Spring
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
- orin stepanek
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Re: Comet Siding Spring
Thanks; by!bystander wrote:http://hubblesite.org/news/2014/19
Orin
Smile today; tomorrow's another day!
Smile today; tomorrow's another day!
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Re: Comet Siding Spring
I first read about this comet and its coming encounter with Mars on Oct. 19, 2014 a little over a year ago:
http://www.skyandtelescope.com/communit ... 06441.html
Comparing early reports to the new makes it seem that the comet is likely to pass even closer to Mars than what was originally thought, although even a year ago orbital predictions where coming up with non-zero likelihoods of the comet actually impacting Mars. Has an impact possibility been ruled out?
When the news came out I had also asked about the possibility of a near miss with Mars causing a breakup of the comet, like the one that happened to Shoemaker-Levi 9. Has this possibility been ruled out?
Bruce
http://www.skyandtelescope.com/communit ... 06441.html
Comparing early reports to the new makes it seem that the comet is likely to pass even closer to Mars than what was originally thought, although even a year ago orbital predictions where coming up with non-zero likelihoods of the comet actually impacting Mars. Has an impact possibility been ruled out?
When the news came out I had also asked about the possibility of a near miss with Mars causing a breakup of the comet, like the one that happened to Shoemaker-Levi 9. Has this possibility been ruled out?
Bruce
Just as zero is not equal to infinity, everything coming from nothing is illogical.
- Chris Peterson
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Re: Comet Siding Spring
Yes. (Or to be more precise, while the odds are non-zero, they are so near zero as to not be worth significant consideration.)BDanielMayfield wrote:Comparing early reports to the new makes it seem that the comet is likely to pass even closer to Mars than what was originally thought, although even a year ago orbital predictions where coming up with non-zero likelihoods of the comet actually impacting Mars. Has an impact possibility been ruled out?
It can't be, because it depends on the unknown nature of the nucleus. But it's probably pretty unlikely.When the news came out I had also asked about the possibility of a near miss with Mars causing a breakup of the comet, like the one that happened to Shoemaker-Levi 9. Has this possibility been ruled out?
Chris
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- MargaritaMc
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Re: Comet Siding Spring
Gosh, Bruce! You're a time traveller!BDanielMayfield wrote:I first read about this comet and its coming encounter with Mars on Oct. 19, 2014 a little over a year ago:
Bruce
M
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
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- neufer
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Re: Comet Siding Spring
Chris Peterson wrote:It can't be, because it depends on the unknown nature of the nucleus. But it's probably pretty unlikely.BDanielMayfield wrote:
When the news came out I had also asked about the possibility of a near miss with Mars causing a breakup of the comet, like the one that happened to Shoemaker-Levi 9. Has this possibility been ruled out?
http://en.wikipedia.org/wiki/Comet_Siding_Spring wrote:
<<Comet Siding Spring will pass extremely close to Mars on 19 October 2014 at 18:30 UTC, so close that the coma may envelop Mars. It will pass Mars at a relative velocity of 56 km/s. The nominal pass is 135,000 km from the center-point of Mars and the uncertainty region shows that it will not come closer than 130,000 km.>>
- The Roche limit for tidal disruption from a Martian close encounter is:
8,300 km for a rigid body & 16,100 km for a deformable (fluid like) body.
http://en.wikipedia.org/wiki/Phobos_%28moon%29 wrote:
<<Phobos is the larger and closer of the two natural satellites of Mars. A small, irregularly shaped object with a mean radius of 11 km. Phobos orbits 9,376 km from the Martian surface, closer to its primary than any other known planetary moon. Due to tidal interactions, Phobos is drawing closer to Mars by one meter every century, and it is predicted that in 50 million years it will collide with the planet or break up into a planetary ring.>>
Art Neuendorffer
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Re: Comet Siding Spring
Ha ha. No, no more so than all of us, traveling through time second by second, always in the forward direction.MargaritaMc wrote:Gosh, Bruce! You're a time traveller!BDanielMayfield wrote:I first read about this comet and its coming encounter with Mars on Oct. 19, 2014 a little over a year ago:
Bruce
M
Just as zero is not equal to infinity, everything coming from nothing is illogical.
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Re: Comet Siding Spring
Thanks for those answers Chris and Art.
Bruce
Bruce
Just as zero is not equal to infinity, everything coming from nothing is illogical.