No sign of Comet ISON after pass around sun: scientists


spaminator
#1
No sign of Comet ISON after pass around sun: scientists
Irene Klotz, Reuters
First posted: Thursday, November 28, 2013 04:02 PM EST | Updated: Thursday, November 28, 2013 04:18 PM EST
A comet’s 5.5-million-year journey to the inner solar system apparently ended during a suicidal trip around the sun, leaving no trace of its once-bright tail or even remnants of rock and dust, scientists said on Thursday.
The comet, known as ISON, was discovered last year when it was still far beyond Jupiter, raising the prospect of a spectacular naked-eye object by the time it graced Earth’s skies in December.
Comet ISON passed just 730,000 miles (1.2 million km) from the surface of the sun at 1:37 p.m. EST/1837 GMT on Thursday. Astronomers used a fleet of solar telescopes to look for the comet after its slingshot around the sun, but to no avail.
“I’m not seeing anything that emerged from the behind the solar disk. That could be the nail in the coffin,” astrophysicist Karl Battams, with the Naval Research Laboratory in Washington, said during a live broadcast on NASA TV.“
“It’s sad that it seemed to have ended this way, but we’re going to learn more about this comet,“ he added.
At closest approach, the comet was moving faster than 217 miles per second(350 km per second) through the sun’s atmosphere.
At that distance, it reached temperatures of 5,000 degrees Fahrenheit(2,760 degrees Celsius) - hot enough to vaporize not just ices in the comet’s body, but dust and rock as well.
If the comet or any large fragments survived the close encounter with the sun, they would be visible to the naked eye in Earth’s skies in a week or two.
The comet was discovered last year by two amateur astronomers using Russia’s International Scientific Optical Network, or ISON.
Comets are believed to be frozen remains left over from the formation of the solar system some 4.5 billion years ago.
The family of comets that ISON belongs to resides in the Oort Cloud, located about 10,000 times farther away from the sun than Earth, halfway to the next star.
Occasionally, an Oort Cloud comet is gravitationally nudged out of the cloud by a passing star and into a flight path that millions of years later brings it into the inner solar system. Computer models show ISON was a first-time visitor.
“I hope we see another one soon,“ said Dean Pesnell, project scientist for NASA’s Solar Dynamics Observatory.
Comet ISON is pictured in this November 19, 2013 handout photo by NASA, taken using a 14-inch telescope located at the Marshall Space Flight Center at 6:10 a.m. EST with a three-minue exposure. (REUTERS/Aaron Kingery/MSFC/NASA/Handout via Reuters)

No sign of Comet ISON after pass around sun: scientists | World | News | Toronto Sun
 
WLDB
#2
Unfortunate. I was looking forward to a good show.
 
darkbeaver
#3
"
Quote:

At that distance, it reached temperatures of 5,000 degrees Fahrenheit(2,760 degrees Celsius) - hot enough to vaporize not just ices in the comet’s body, but dust and rock as well.
If the comet or any large fragments survived the close encounter with the sun, they would be visible to the naked eye in Earth’s skies in a week or two.
The comet was discovered last year by two amateur astronomers using Russia’s International Scientific Optical Network, or ISON.
Comets are believed to be frozen remains left over from the formation of the solar system some 4.5 billion years ago.

It was ionized not vaporized.

At about 500 kilometers (310 miles) above the photosphere or visible surface, we find the coldest measurable temperature, about 4400 degrees K. Moving upward, the temperature then rises steadily to about 20,000 degrees K at the top of the chromosphere, some 2200 kilometers (1200 miles) above the Sun's surface. Here it abruptly jumps hundreds of thousands of degrees, then continues slowly rising, eventually reaching 2 million degrees in the corona. Even at a distance of one or two solar diameters, ionized oxygen atoms reach 200 million degrees!
In other words the “reverse temperature gradient,” while meeting the tests of the glow discharge model, contradicts every original expectation of the fusion modelThe Electric Glow of theÂ* Sun


"gravitational nudging"? that's lunaticspeak
 
MHz
#4
1:10 is when it reappears.

Comet ISON 100% Intact and now back on LASCO C3! - YouTube
 
#juan
#5
We've probably seen the last of Comet ISON. If there was anything left, we'd know by now.
 
darkbeaver
#6
So what reappeared?
 
MHz
+1
#7
 
Blackleaf
+1
#8
Comet Ison, or some part of it, may have survived its encounter with the Sun, say scientists.

BBC News - Hope still for 'dead' Comet Ison
 
#juan
#9
Quote: Originally Posted by darkbeaver View Post

So what reappeared?

It looks like some part of ISON came out but at this point it is unknown when, or if we'll see it come back again.
Last edited by #juan; Nov 29th, 2013 at 11:20 AM..
 
petros
+1
#10
I see there are some pretty violent CMEs happening that are just as interesting. The sun is still in angry mode.
 
#juan
#11
Quote: Originally Posted by petros View Post

I see there are some pretty violent CMEs happening that are just as interesting. The sun is still in angry mode.

Comets are usually dragging along a whole cloud of debris to add to that.
 
petros
#12
The comet appears to have slowed and was flung on a new trajectory.

It would have been interesting to see a CME nail the comet.
 
#juan
#13
Quote: Originally Posted by petros View Post

The comet appears to have slowed and was flung on a new trajectory.

It would have been interesting to see a CME nail the comet.

Comet ISON's nucleus was only about three miles in diameter before it's little joust with the sun. Hard to say if it will make it back to the Oort cloud or where ever it came from
 
petros
#14
I wonder what the next dominant creature is that will be delivered by comet from the Oort cloud when we are gone?
 
#juan
+2
#15  Top Rated Post
Quote: Originally Posted by petros View Post

I wonder what the next dominant creature is that will be delivered by comet from the Oort cloud when we are gone?

We wouldn't want an Andromeda Strain...how about something more friendly...like the Shmoos out of Lil Abner....
 
MHz
#16
Oh yeah, the reason for the late night visit.

 
spaminator
#17
Comet ISON showing signs of life?
'Zombie' comet may be back from the dead
Irene Klotz, reuters
First posted: Friday, November 29, 2013 12:05 PM EST | Updated: Friday, November 29, 2013 05:06 PM EST
CAPE CANAVERAL, FLA. - A smaller, paler version of Comet ISON may have survived incineration in the sun’s corona and may be brightening, scientists said on Friday.
Since its discovery in September 2012, Comet ISON has been full of surprises. It started off extremely bright, considering its great distance from the sun at the time, beyond Jupiter’s orbit.
As it drew closer, it did not brighten as much as expected, raising doubts about its size and the amount of water it contained. Ice in a comet’s body vaporizes from solar heating, causing a bright stream of particles to trail the body in a distinctive tail.
Conflicting pictures of the comet’s future continued until Thursday when ISON apparently flew too close to the sun. Its long tail and nucleus seemingly vaporized in the solar furnace, dashing hopes of a naked-eye comet visible in Earth’s skies in December.
But late on Thursday, ISON surprised again.
“A bright streak of material streaming away from the sun appeared in the European Space Agency and NASA’s Solar and Heliospheric Observatory later in the evening,” NASA wrote on its website on Friday.
“The question remains whether it is merely debris from the comet, or if some portion of the comet’s nucleus survived,” the U.S. space agency said.
Preliminary analysis suggests that at least a small nucleus is intact.
“One could almost be forgiven for thinking that there’s a comet in the images,” astrophysicist Karl Battams, with the Naval Research Laboratory in Washington, wrote in a blog posted Thursday night.
“Right now it does appear that a least some small fraction of ISON has remained in one piece and is actively releasing material,” Battams wrote.
“If there is a nucleus, it is still too soon to tell how long it will survive. If it does survive for more than a few days, it is too soon to tell if the comet will be visible in the night sky. If it is visible in the night sky, it is too soon to say how bright it will be ... I think you get the picture, yes?” he added.
The comet was discovered last year by two amateur astronomers using Russia’s International Scientific Optical Network, or ISON.
Comets are believed to be frozen remains left over from the formation of the solar system some 4.5 billion years ago.
The family of comets that ISON is from resides in the Oort Cloud, which is about 10,000 times farther away from the sun than Earth, halfway to the next star.
Computer models show it left the outer edge of the solar system about 5.5 million years ago and began journeying toward the sun.
At its closest approach on Thursday, it passed just 730,000 miles (1.2 million km) from the sun’s surface and experienced temperatures reaching 5,000 degrees Fahrenheit (2,760 degrees Celsius.)
“This has unquestionably been the most extraordinary comet that ... I, and many other astronomers, have ever witnessed,” Battams wrote. “This story isn’t over yet.”
Comet ISON showing signs of life? | World | News | Toronto Sun
 

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