Tag Archive | comet

A Naked Eye Visible Comet, FINALLY, 21P/Giacobini–Zinner — In September 2018.

by Anura Guruge

Click to ENLARGE and read here. Wikipedia: en.wikipedia.org/wiki/21P/Giacobini–Zinner

Click to ENLARGE and admire. From the JPL Small-Body Database Browser.

It will NOT be spectacular, and it is definitely not a great comet, BUT, if it is naked eye visible, it, with its green tinge (due to its chemical composition), should be quite the sight up there. We have not see a decent comet since the mid-1980s. Comet ISON, on which I expended considerable time and energy, vaporized when it got too close to the Sun.

No such danger with 21P/Giacobini–Zinner. This is not a sungrazer.

The ‘P’ in the 21P denotes that it is a periodic comet; i.e., a comet that has made at least 2 well observed orbits around the Sun. Actually 21P orbits the Sun every 6 years. It is very periodic. It doesn’t go too far away. Just beyond the orbit of Jupiter. It is well known and well studied comet that was discovered in 1900.

I will keep you posted. I was excited to hear that it might be naked eye visible. Wow.

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by Anura Guruge

Edmond Halley, Of Comet Fame, The British Polymath Genius, Was Born This Day, 361 Years Ago.

by Anura Guruge

Click to ENLARGE and read here. Wikipedia: en.wikipedia.org/wiki/Edmond_Halley

I did a post on Edmond Halley (29 October 1656 to 14 January 1741 (new Gregorian calendar)), on the anniversary of his death, on January 14, 2017.

So, I am not going to repeat myself. {Smile}. Instead I am giving you the above two YouTube videos, which are good, and the Wikipedia entry.


But, please check my earlier post. You will be glad that you did.

Google Doodle for Edmond Halley's 355th Birthday, November 8, 2011 (old calendar).

Google Doodle for Edmond Halley’s 355th Birthday, November 8, 2011 (old calendar).

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by Anura Guruge

A/2017 U1 — Too Speculative To Claim That It Is ‘Interstellar’.

by Anura Guruge

Click to ENLARGE. From NASA/JPL @ http://www.jpl.nasa.gov.

Click to ENLARGE. Wikipedia: en.wikipedia.org/wiki/A/2017_U1

Definitely extremely interesting and intriguing. Wow. Orbital eccentricity of 1.1922! The greatest we have ever seen — the keywords here being ‘ever seen’. Comet ISON, that crashed and burned on Thanksgiving Day 2013 had an eccentricity of 1.0000015.

But, here is the deal with eccentricity. Anything over 1.0 means that the object will eventually leave our Solar System. That we know. But, what we cannot tell as yet is WHEN A/2017 U1 got that highly eccentric orbit. We just do NOT know — as yet. And maybe never will.

To claim that it must have originated OUTSIDE of our Solar System — is speculative. We do NOT have enough evidence.

NASA/JPL’s official statement confirms that: “So far, everything indicates this is likely an interstellar object, but more data would help to confirm it.” Note the ‘likely‘ and the part about ‘more data … for confirmation‘. That is exactly MY POINT and what I am trying to impress.

The claim that its orbit was NOT influenced by a close encounter with a planet — typically one of the BIG ones — is speculative. It could have been majorly torqued around by Uranus or Neptune. We don’t know.

I have a druthers that this is a very old comet — a periodic one at that, which on its last trip out, maybe 400 years ago got too close to a gas giant and had its orbit turned ‘upside down’.

We don’t know.

All I am stressing is do NOT jump to conclusions.

We know so little about what has happened in OUR Solar System and what is happening right now.

But, it is exciting.

Has a ton of good information about comets.

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by Anura Guruge

2017 Perseids Meteor Shower, Over New England, As Usual Will Peak Around August 11 – 13.

by Anura Guruge

Perseids Meteor Shower over New Hampshire New England

The Perseids Meteor Shower happens each and every year, without fail, in ‘mid-August’. This is because at that time the Earth crosses the path of the repeatedly left behind debris from the periodic comet 109P/Swift-Tuttle — which orbits the Sun with a 133.28 year orbital period. It was discovered in 1862 BUT may have been orbiting the Sun long before that. It was last seen from Earth in 1992. The next time around be in 2126.

It is difficult to predict how good (i.e., spectacular) it will be in a given year. In 2016 they said it would be huge — but it didn’t quite live up to the billing though I did see a few. The weather might not cooperate this year — though it is a bit early to tell. Rain is predicted for August 11, though this could change. There will be some moon BUT that should not be an issue.

109P/Swift-Tuttle has an perihelion distance of 0.96 AU (i.e., just inside Earth’s orbit) and an aphelion of 51.2 AU — which takes it past Pluto.

The name of the Meteor Shower, i.e., Perseids, comes from the constellation Perseus — where the meteors appear to originate. See image above.

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by Anura Guruge

Comet ‘Shoemaker-Levy 9’ That Gave Jupiter Quite The Black Eye Was Discovered This Day, 24-Years Ago.

by Anura Guruge

Jupiter’s gravitational pull broke up the comet way before the fragments went on to strike Jupiter.

From MY BOOK “Comets: 101 Facts & Trivia”. Click to ENLARGE and read here. Click image below for more details of BOOK.

While the discovery per se was NOT big news, the cometary fragments slamming into Jupiter in July 1994 was indeed widely publicized and covered.

I remember watching it on TV.

This is a comet I am quite familiar with.

We learned a lot from it, especially the phenomenon of Jupiter capturing comets before they made it to the Sun.

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by Anura Guruge

Today, March 3, 64-Years Ago (1953), Was The Beginning Of The End Of The de Havilland Comet (4).

by Anura Guruge


Click to ENLARGE and ADMIRE here.


Click image to download and read complete PDF from the NTSB.

The de Havilland Comet, in particular the Comet 4, was my first love when it came to planes — and it has been a lifelong infatuation starting from when I was about 2. The Comet 4, flown by BOAC, was the first jet plane I ever saw — in Colombo, Ceylon. I never got to fly on it. My adopted parents did. I saw them take-off in one. It used to have this amazingly steep climb — much steeper than today’s jet.

This March 3 crash was the 1st in 26 — which eventually led to it being decommissioned.


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by Anura Guruge

How & Where To See Comet, 45P, February 9 – 12, 2017, As It Makes Close Approach.

by Anura Guruge

Click to ENLARGE.

Comet P45 where to see

For North America.


Though it will be close, it is NOT a very big comet. Plus, being a PERIODIC that goes around the Sun once every 5.25 years, and has been doing so for a long time, it has expended some/much of its frozen ices that vaporize to create the tail. So it will NOT be putting on a dazzling show. If anything it will JUST (and I mean JUST) be naked eye visible. Best to try and see it with a telescope or a pair of binoculars.

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by Anura Guruge

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