CR4® - The Engineer's Place for News and Discussion®


Previous in Forum: A Fib Treatment.   Next in Forum: Partial Lunar Eclipse Right Now
Close
Close
Close
21 comments
Guru

Join Date: Apr 2010
Posts: 5817
Good Answers: 589

Green Comet This Weekend

02/09/2017 9:06 PM

Comet 45P/Honda-Markos-Pajdušákov will be at its closest point to earth, 7.4 million miles on the morning of February 11 (Sunday). It may be barely visible to the naked eye.

http://www.cbsnews.com/news/comet-45p-closest-in-decades-lunar-eclipse-february-2017/

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19481
Good Answers: 1141
#1

Re: Green comet this weekend

02/09/2017 9:57 PM
__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru

Join Date: Dec 2016
Posts: 2914
Good Answers: 115
#2

Re: Green comet this weekend

02/09/2017 11:35 PM

45P is currently tail-less and extremely faint. It will appear fainter than in this 6-second time exposure taken Feb 8. Binoculars are highly recommended.

The comet glows green from ionised carbon fluorescing in the Sun's UV.

-----

Where to find the comet:

Register to Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9580
Good Answers: 457
#3

Re: Green comet this weekend

02/10/2017 6:48 AM

When seeing pictures like this, it's difficult (for me, anyway) to throw off the almost instinctive feeling that the tail is streaming out behind the comet as it streaks through the æther.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply
Guru
Engineering Fields - Instrumentation Engineering - EE from the the Wilds of Pa.

Join Date: Feb 2006
Location: middle of nowhere, Pennsylvania
Posts: 2510
Good Answers: 59
#4

Re: Green comet this weekend

02/10/2017 8:40 AM

A comet and Andrew Westman reports there will be a lunar eclipse. If this were 1017, not 2017, dire events would be expected. Certainly looks like the signs of a bad omen.

__________________
Remember when reading my post: (-1)^½ m (2)^½
Register to Reply
Guru

Join Date: Apr 2008
Location: Chicago
Posts: 2298
Good Answers: 73
#5

Re: Green Comet This Weekend

02/10/2017 11:10 AM

green comet up close

__________________
High Tolerance is Beautiful
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13899
Good Answers: 155
#7
In reply to #5

Re: Green Comet This Weekend

02/10/2017 12:26 PM

Better keep the lid on that if you are going to come in here shaking than can of powder.

Ride the comet and vomit today... catching jingle.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru
Hobbies - DIY Welding - Wannabeabettawelda

Join Date: May 2007
Location: Annapolis, Maryland
Posts: 4207
Good Answers: 237
#10
In reply to #7

Re: Green Comet This Weekend

02/10/2017 2:01 PM

Comet . . .

. . . it makes your teeth turn green, Comet . . .

. . . it tastes like gasoline, Comet . . . .

. . . it makes you vomit, take some Comet and vomit today.

Register to Reply Off Topic (Score 5)
Guru

Join Date: Dec 2016
Posts: 2914
Good Answers: 115
#11
In reply to #10

Re: Green Comet This Weekend

02/10/2017 2:15 PM

"Desperation"

Register to Reply Off Topic (Score 5)
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13899
Good Answers: 155
#12
In reply to #10

Re: Green Comet This Weekend

02/10/2017 2:15 PM

Thank you Brave and kind Sir Robin.

May I have another cocktail of comet?

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Off Topic (Score 5)
Guru
Hobbies - DIY Welding - Wannabeabettawelda

Join Date: May 2007
Location: Annapolis, Maryland
Posts: 4207
Good Answers: 237
#13
In reply to #12

Re: Green Comet This Weekend

02/10/2017 4:44 PM

It's funny I can remember the fractured fairy tales version of that advertising ditty from my childhood but not the original words.

Register to Reply Off Topic (Score 5)
Anonymous Poster #1
#17
In reply to #12

Re: Green Comet This Weekend

02/11/2017 4:15 PM

Be careful, for what you fear will come to you.

Your reward

Register to Reply Off Topic (Score 5)
Guru

Join Date: Apr 2008
Location: Chicago
Posts: 2298
Good Answers: 73
#18
In reply to #17

Re: Green Comet This Weekend

02/11/2017 5:25 PM

ya know.. that's not really very annon.. just sayin'

__________________
High Tolerance is Beautiful
Register to Reply Off Topic (Score 5)
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13899
Good Answers: 155
#20
In reply to #17

Re: Green Comet This Weekend

02/13/2017 11:10 AM

Gee thank you for the absurd warning. I have already read that passage before, and placed my offering in the collection plate, thank you very much.

I have laid out no snares for the righteous, so I feel very comfortable about my relationship with my Savior right now. I have my religion and you have yours.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Off Topic (Score 5)
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13899
Good Answers: 155
#6

Re: Green Comet This Weekend

02/10/2017 12:20 PM

Sunday is 12 February, 2017, so you are one day off in your statement by half the statement either way, Pick your poison please? Red pill or blue? Either way, something will change.

That green color is I suspect not specifically "carbon", but rather the famous C2 "Swan" bands observed in flames and other excitations of carbonaceous sources. Another spectrum is usually seen with, in various ratio that is the CH electronic spectrum.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Dec 2016
Posts: 2914
Good Answers: 115
#8
In reply to #6

Re: Green Comet This Weekend

02/10/2017 1:24 PM

"... not specifically "carbon", but rather the famous C2 ..."

Well, just so long as C2 isn't carbon, we're safe lol. Another other big contributor to the glow is CN2 - cyanide (from the Greek κυανος [kyanos], meaning 'blue'). In 1910 some people feared Earth might be poisoned by its passage through Halley's comet's bluish cyanogen tail.

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13899
Good Answers: 155
#9
In reply to #8

Re: Green Comet This Weekend

02/10/2017 1:44 PM

Oh snap, I forgot to mention the CN bands (and CN2 ion), good catch.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Apr 2010
Posts: 5817
Good Answers: 589
#15
In reply to #9

Re: Green Comet This Weekend

02/10/2017 9:28 PM

A frequently-asked question: Why do some comet atmospheres glow green?

Answer: The coma contains cyanogen (CN), a poisonous gas, and diatomic carbon (C2). Both of these substances glow green when illuminated by sunlight. This is called "resonant fluorescence."

https://science.nasa.gov/science-news/science-at-nasa/2005/05jan_machholz

Cyanogen gas is actually two cyanide ions, CN-, combined, (CN)2

https://en.wikipedia.org/wiki/Cyanogen

Register to Reply
Guru

Join Date: Apr 2010
Posts: 5817
Good Answers: 589
#14
In reply to #6

Re: Green Comet This Weekend

02/10/2017 7:09 PM

Make that Saturday. (We retired folks seldom know what day of the week it is. )

Register to Reply
Guru

Join Date: Sep 2016
Posts: 767
Good Answers: 8
#16

Re: Green Comet This Weekend

02/11/2017 2:39 AM

Looks like green lantern is paying a visit.

Register to Reply
Guru

Join Date: Feb 2013
Posts: 1311
Good Answers: 21
#19
In reply to #16

Re: Green Comet This Weekend

02/12/2017 5:48 AM

No, not so much a Green Lantern, more like an bad LED.

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13899
Good Answers: 155
#21
In reply to #19

Re: Green Comet This Weekend

02/13/2017 11:12 AM

It was apparently about the intensity of an LED at 7 million miles out. I could not find it, but sometimes I can't even find Vega.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Register to Reply 21 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Andrew Westman (3); Anonymous Poster (1); Brave Sir Robin (2); gutmonarch (1); IQ (1); James Stewart (6); JE in Chicago (2); JohnDG (1); Phys (1); Rixter (2); SolarEagle (1)

Previous in Forum: A Fib Treatment.   Next in Forum: Partial Lunar Eclipse Right Now

Advertisement