ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Comet Halley (Halley's Comet)

Updated on January 12, 2015

Comet Halley

March 23, 1986 | 30 second exposure, started at 4:33 am local time (14:33 Greenwich Mean Time — Coordinated Universal Time [UTC]), Tahiti International Golf Course, Commune of Papara, Tahiti, French Polynesia | Kodak Tri-X film, no filter
March 23, 1986 | 30 second exposure, started at 4:33 am local time (14:33 Greenwich Mean Time — Coordinated Universal Time [UTC]), Tahiti International Golf Course, Commune of Papara, Tahiti, French Polynesia | Kodak Tri-X film, no filter | Source
April 11, 1986 | 17 minute 55 second exposure, started at 3:09 am local time (13:09 Greenwich Mean Time — Coordinated Universal Time [UTC]) | Tahiti International Golf Course, Commune of Papara, Tahiti, French Polynesia | Fujichrome 400 film
April 11, 1986 | 17 minute 55 second exposure, started at 3:09 am local time (13:09 Greenwich Mean Time — Coordinated Universal Time [UTC]) | Tahiti International Golf Course, Commune of Papara, Tahiti, French Polynesia | Fujichrome 400 film | Source

What is a Comet?

Comets are leftovers from the formation of the solar system, about 5000 million years ago. Near to the sun, small rocky planets such as Earth formed. Further out, large gas planets like Jupiter formed. Still further out, the masses of dust and ice didn't form planets. They stayed separate and formed a cloud of comets known as Oort's cloud.

Most comets are undetectable from Earth. Occasionally two comets may collide, and an icy piece of one of them falls toward the sun. The journey toward the sun takes several hundreds of thousand of years. Once the comet reaches the sun, it swings past it and returns to Oort's cloud, in as much as a million years since it left.

Short-Period Comets

Some comets orbit the sun much more frequently than what I've just described. These short-period comets have been captured by the solar system.

When a comet travels toward the sun, it passes all the planets in the solar system. Some of the smaller planets have no effect on the comet. If the comet passes too close to a larger planet—Jupiter or Saturn—it may become trapped. The gravitational force of a planet such as Jupiter or Saturn will slow the comet, leaving it without enough energy to return to Oort's cloud.

Halley's Comet is a Short-Period Comet

A comet which has been caught in the gravitational force of one of the larger planets is doomed to spend the rest of its life orbiting the sun in much less time than the one million year round-trip between Oort's cloud and the sun. Comet Halley is a short-period comet. It orbits the sun every 76 years.

The 1986 Apparition of Comet Halley

Comet Halley's most recent apparition was in 1986. Within a three-week period in March 1986, a group of six spacecraft flew past the nucleus of Comet Halley, at distances ranging from 17.4 miles to 372.8 miles. Professional and amateur astronomers, organized into nine disciplines of the International Halley Watch, monitored Halley's Comet using ground-based instrumentation. The scope and size of the international scientific community organized to study Comet Halley was unprecedented in the history of science.

International Halley Watch (IHW)

The United States Congress appropriated funding for the formation of the International Halley Watch (IHW). In 1980, a National Aeronautics and Space Administration (NASA) science working group was formed to establish the objectives of the organization. NASA Headquarters established two lead centers for the IHW, one in Germany, and the other at the Jet Propulsion Laboratory (JPL) in Pasadena, California.

Nine observing disciplines (networks) were formed to encourage, coordinate, and archive the scientific data resulting from the observations of Comet Halley during its apparition from 1982 to 1989.

The Schmidt Camera used at the observing site on the grounds of the Tahiti International Golf Course in the Commune of Papara on the island of Tahiti in French Polynesia
The Schmidt Camera used at the observing site on the grounds of the Tahiti International Golf Course in the Commune of Papara on the island of Tahiti in French Polynesia | Source

IHW Small Island Network

The International Halley Watch's Large-Scale Phenomena Team was responsible for establishing a worldwide network to observe and photograph Comet Halley. More than 90 observatories in the Northern Hemisphere had the comet in view during every hour in each 24-hour period.

The situation changed in February 1986, when Halley's Comet rounded the sun. The comet was far south of the celestial equator and either difficult or impossible to see from many northern observatories. The Southern Hemisphere is dominated by oceans. The observatories there were too far apart to continuously monitor the comet. One of the nine networks formed by the IHW's Large-Scale Phenomena Team was the Small Island Network.

The idea of the Small Island Network was to place portable Schmidt cameras on remote islands to monitor the comet. The IHW's Large-Scale Phenomena Team only had funds to purchase the equipment. One of the most difficult aspects of the program was finding volunteers to operate the cameras. The six locations chosen to be in the Small Island Network were Tahiti, Easter Island, the British Antarctic Survey's Faraday Station on the Antarctic Peninsula, the South African Astronomical and Cedarberg observatories (both on the mainland), and Reunion Island.

My observing partner and I spent a month in Tahiti observing and photographing Comet Halley for the International Halley Watch's Small Island Network!

Comet Observation

Have you ever observed and photographed a comet?

See results

Update: 8/6/2012

This article received the 2012 HubPages Hubbie Award for Most Interesting Hub. My heartfelt thanks to everyone who voted.

working

This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://corp.maven.io/privacy-policy

Show Details
Necessary
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
Features
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Marketing
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Statistics
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
ClickscoThis is a data management platform studying reader behavior (Privacy Policy)