Lecture 22:
Comets & Meteor Showers
Comet Ikeya-Seki
(C/1965 S1)
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Comets & Meteor Showers: Analyzing Composition, Orbits, & Phenomena, Study notes of Astronomy
An extensive exploration of comets and meteor showers, discussing their composition, anatomy, orbits, and the phenomena surrounding their appearance. Topics include the discovery of comets by edmond halley, the differences between short- and long-period comets, and the origins of meteor showers. Students will gain valuable insights into the scientific concepts related to these celestial bodies.
Typology: Study notes
Pre 2010
1 / 33
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Comets & Meteor Showers: Analyzing Composition, Orbits, & Phenomena and more Study notes Astronomy in PDF only on Docsity!
Lecture 22:
Comets & Meteor Showers
Comet Ikeya-Seki (C/1965 S1)
What is a comet?
Composition
- Ices mostly H 2 O, also CO 2 , CO, NH 3 , CH4, H 2 CO Rock & Dust - silicates, carbon compounds Nucleus
- Typical size: a few km; smaller probably common; rarely 10 km - 100+ km; Coma
- surrounds nucleus when near the Sun
- sublimated gas & dust Comets are “dirty snowballs”…ice mixed with rock and dust. Gas / Plasma / Ion tail
- ionized gas swept back by solar wind Dust tail
- dust particles swept back more slowly by radiation pressure
How a comet gets its tail…
A Point of Confusion…
Comets move slowly from night to night relative
to the background stars.
Hale-Bopp 2/28/97 Hale-Bopp 2/24/
Edmond Halley
Edmond Halley (1656-1742) was the first to realize that comets orbit the Sun, as do the planets. Using the method developed by Isaac Newton (1642-1727), Halley computes the orbits for 24 comets. He discovers that the orbits of the comets of 1531, 1607, and 1682 are very similar! Could they be the same comet coming around again and again? Halley predicts that the comet will again return in late 1758 or early 1759. The comet does indeed return as predicted, and the comet is named after Halley, 16 years after his death.
Comet Halley (1P/Halley)
- First recorded in China in 240 B.C.
- Closest to Earth 837 A.D. (0.03 AU)
- Last return to inner solar system 1986
- Next return to inner solar system 2062
- Current orbital period is 76 years
Comet Hale-Bopp
Comet Hale-Bopp (C/1995 O1)
Kreutz “Sungrazing” Comets
Sublimation
Sublimation
occurs when a
solid converts
directly to a
gas without
going through a
liquid stage
first.
NASA’s
Deep Space 1
photographs the gas & dust jets of Comet Borrelly on 9/22/01.
ESA’s Giotto spacecraft
photographs
Comet Halley
on March 13,
1986 at a
distance of
600 km from
the nucleus.
Potato-shaped Halley has a nucleus that is roughly 15 km across.
Comet Wild 2
From Stardust Nucleus is roughly 5 km across.