Update 3/12/2009 Modified by C. IppolitoMarch 2009

Rendezvous with a CometRendezvous with a Comet

Courtesy: Pat Rawlings - Deep Impact -NASA & JPL

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

IntroductionIntroduction

1000 BC from the Chinese records Omen, even as recently as 1986.

Battle of Hastings - 1066

Now studied from scientific aspect

1000 BC from the Chinese records Omen, even as recently as 1986.

Battle of Hastings - 1066

Now studied from scientific aspect

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Dirty SnowballsDirty Snowballs

as they orbit around the sun they partially vaporize

elliptical orbits

as they orbit around the sun they partially vaporize

elliptical orbits

Courtesy: Calvin J. Hamilton

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Structure of a CometStructure of a Comet

Solar heat vaporizes Coma - Hydrogen gas

Envelope Dust tail Ion tail

Solar heat vaporizes Coma - Hydrogen gas

Envelope Dust tail Ion tail

Courtesy: Deep Impact - NASA & JPL

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Orbits of CometsOrbits of Comets

Elliptical in Shape Randomly oriented

Elliptical in Shape Randomly oriented

Sun

Comet

Earth

Perihelion distance

Aphelion distance

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Comet HuntersComet Hunters

Named by International Astronomical Union (IAU) after discoverer

Often discovered by amateurs. Charles Messier E. E. Bernard Shoemaker and Levy (hit Jupiter) Hale and Bopp

Named by International Astronomical Union (IAU) after discoverer

Often discovered by amateurs. Charles Messier E. E. Bernard Shoemaker and Levy (hit Jupiter) Hale and Bopp

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Origins of CometsOrigins of Comets

debris from formation of the solar system. elliptical orbits influenced by gravitational

pull of giant planets. Two possible “home” locations:

Kuiper Belt Oort Cloud

debris from formation of the solar system. elliptical orbits influenced by gravitational

pull of giant planets. Two possible “home” locations:

Kuiper Belt Oort Cloud

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Possible Homes for CometsPossible Homes for Comets

Kuiper Belt Gerard Kuiper

1951) Elliptic 30 to 500 AU 100,000 objects

Oort Cloud Jan Oort (1950) spherical. 50,000 AU

from the Sun. 5 trillion

objects.

Kuiper Belt Gerard Kuiper

1951) Elliptic 30 to 500 AU 100,000 objects

Oort Cloud Jan Oort (1950) spherical. 50,000 AU

from the Sun. 5 trillion

objects.Courtesy - Deep Impact - NASA - JPL

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Comets and their periodsComets and their periods

Jupiter-family: Kuiper belt 20 years. Gravitational perturbations by Neptune Elliptical orbits close to the Sun Or Captured by Saturn as outer satellites

Jupiter-family: Kuiper belt 20 years. Gravitational perturbations by Neptune Elliptical orbits close to the Sun Or Captured by Saturn as outer satellites

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Update 3/12/2009 Modified by C. IppolitoMarch 2009

Comets TailsComets Tails Ludwig

Biermann solar wind causes

comet tails. Mariner 2 (1962.)

Ludwig Biermann solar wind causes

comet tails. Mariner 2 (1962.)

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Comets TailsComets Tails THREE Tails.

Blue Ion Tail ionized atoms of CN and C2.

Dust Tail sun photons hit dust particles produce radiation pressure. curved shape.

Sodium Tail invisible to unaided eyes.

THREE Tails. Blue Ion Tail

ionized atoms of CN and C2.

Dust Tail sun photons hit dust particles produce radiation pressure. curved shape.

Sodium Tail invisible to unaided eyes.

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Comet CollisionsComet Collisions Earth

devastation to life on Earth.

Jupiter Shoemaker-Levey

taped important facts about Comet collisions.

Earth devastation to life on Earth.

Jupiter Shoemaker-Levey

taped important facts about Comet collisions.

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