Halley’s Comet

Bookmark added to your notes.
View Notes


Coming down to the brass tracks of defining what’s a comet: it consists of frozen gases,rocks and dust  just like a snowball that orbits the sun.

One of the very famous features of a comet is having a tail and that occurs due to the process  called outgassing.

Comet is icey and when it comes near the sun it warms and starts releasing  gases filled inside it:  this is outgassing which creates a tale in a comet.

The nuclear of a comet gets affected due to solar radiation and solar wind due to which this phenomenon occurs.

It's noted that the coma is around fifteen times the diameter of earth and its tail stretches one astronomical unit.

[Image will be Uploaded Soon]

Edmond Halley

Edmond Halley was an english scientist and he was known for predicting the orbit of the comet that was later named after him “Halley's comet”. It was discovered in the year 1758.

He also did research work and discoveries in the field of geophysics,maths,metrology and physics.

He was born on november 8th 1656 in haggerston shoreditch london england.

His 1st observation was of a transit of mercury and realized that a similar transit of venus can be used to measure the size of the solar system .

And due to his keen interest in the field of science he became the youngest(22) member of the prestigious scientific group.

Halley’s Comet Dates

The halley’s comet which is officially said or designated as 1p/halley, appears in the short period of 75 years or 76 years from the earth ,and it can be easily observed from the naked eyes. This might appear twice in human life.

Physical characteristics :

Diameter: 15 km*8kmpower[3] = 15 km x

Mass: 2.2*14power[14] = 22 x 14¹⁴

[Image will be Uploaded Soon]

Halley’s Comet Orbit

Though halley’s orbiting  period is now vairing from 74 to 79 years 

Its orbiting is totally elliptical around the sun.

Its orbit is retrograde and is between venus and mercury it moves anti direction with respect to the planets.due to its feature of being retrograde it has good inclination of 120 degree to the south pole and it has high velocity because of  its retrograde rotation.

[Image will be Uploaded Soon]

Helley’s is also known as the short period comet as its  orbit is lasting 200 years or less.


Earlier the comets in the sky were thought to be the atmospheric anomalies .

But all these things or point of view was shaken when Halley proposed his theories and observation on the comet which is now named after him.

His observations were based on the gravitational theories of sir Isaac Newton to chart the paths of two frozen comets.

He argued that his comet has an elliptical path and it returns every 75 to 76 years as earlier it was thought to return centuries later .

Though he died in the year 1742 but his comet still appeared in the sky on christmas eve on the scheduled date.

Hallye’s Comet Year 

Halley’s comet was observed in the year 1682 by Halley. It appears usually at the night time in the sky and it orbits the sun in around every 75 or  76 years’

It was later seen in 1758,1835,1910,1986.

And last time it was observed in 1986 then this time it’s predicted to be seen in 2062.

Informations about Hallye’s Comet 

A halley’s comet consists of water and many gases e.g. methane , ammonia, carbon dioxide etc etc.

As it’s an icey cool rocked structure and its path is also elliptical so as soon as it reaches the soon the gases and ice inside it expands and develop into a tail which later  appears like a beautiful shooting star from the observation point or from earth.

Halley’s Comet Last Appearance : 

Here are some images which shows appearance of the comet from the sky:

[Image will be Uploaded Soon]

This was last observed in 1986 and next it appeared in 2062.The chinese astronomers recorded its passage in the  Shih Chi and Wen Hsien Thung Khao chronicles. 

Halley’s Comet Appearance 

As we know that it always shows up nearly every 75 year the last it was observed on the year 1986.as it reaches the sun its all gases expands which knocks it slightly out of its own parth now this whole process causes the comet to develop a bright tail of ionized gases and its front side is made up of dust particles.

About Halley’s Comet

Around two hundred thousands years ago the famous comet halley was  captured by Jupiter into a short periodical orbital.

It also appeared in the medieval skys when the nomens concerned the england peoples.

It’s passing could not be recorded but its return was recorded first photographed in 1910.

And it appeared again in the space age .There were many international efforts  made  by many countries to know about it and capture it .

Meaning of Hallye’s Comet  

Though the comet has vaste coma still its small with a nucleus of around 15km long 8km wide and 8km thick.its was also observed that the gases which it emitted had 80% of water ,3 to 4% carbon dioxide and 17% carbon monoxide with traces of hydrocarbons.

It will next appear in 2062 but the predictions are though not good on life sustainable  on earth.

Still old science says that they  brought water to the planets.

Origin and Orbit of Halley’s Comet

Comets have orbits which are periodicals unlink the theory of ancient people that they go straight. Comets generally are found at the end  solar system or at its edge. Along with comets many more gases are also there and so the halley’s comets or clouds . it orbits the sun in ever 74 to 79 years at times 75 or 76 around. Comets  are of two types large comets and short orbit comets , the halley’s comet falls under the short orbital comet category. 

FAQ (Frequently Asked Questions)

Q1. Why is Halley's Comet Known as the Most Famous Comets?

Ans: Halley’s comet is also known as the 1P/Halley . It's known to be a very famous comet because it was for the first time that astronomers started understanding comets,and that comet could be a repeat visitor to our night sky.

Q2. Why Does it Appear?

Ans: Halley’s orbit is very short and near the sun so its volatile compounds begin to sublimate from the surface of its nucleus. This is the reason that the comet develops a coma or atmosphere upto 100000km across.

Q3. Why Do We Often See Halley's Comet in 75 Years?

Ans: We see it every 75 or 76 years because the difference between their orbits is that the comet's orbit is very much elongated or can say elliptical while the planet's orbit is round. This is the major reason we see it after every 75 or  76 years.