* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Comet - Physics
Survey
Document related concepts
History of Solar System formation and evolution hypotheses wikipedia , lookup
Planet Nine wikipedia , lookup
Planets in astrology wikipedia , lookup
Sample-return mission wikipedia , lookup
Definition of planet wikipedia , lookup
Planets beyond Neptune wikipedia , lookup
Late Heavy Bombardment wikipedia , lookup
Near-Earth object wikipedia , lookup
Kuiper belt wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Scattered disc wikipedia , lookup
Halley's Comet wikipedia , lookup
Comet Shoemaker–Levy 9 wikipedia , lookup
Transcript
Goal: To understand what comets are and to explore the Oort cloud. Objectives: 1) To learn about what comets are 2) To understand where comets come from 3) To explore what comets are made of 4) To examine the different tails of comets 5) To understand the evolution of comets 6) To Explore Aurora 7) To examine satellites What is a comet? • Try to think deep here… • Draw a picture too. What is a comet? • Size • Structure • Orbit Where do comets come from? • • • • Short period comets (periods < 300 years): Option 1: When 2 icy TNOs collide. A debris cloud will be formed. This “debris” cloud will have several rubble piles which are a few km in size. • These rubble piles will travel in random directions. Some will fall in towards the sun. Short period comets – cont. • Usually they will start with an orbit which takes them to the gas giant region. Here the objects will be called Centaurs. • Eventually these Centaurs will have a close encounter with a gas giant (don’t worry Jupiter, I won’t name any names). • At this point they either collide with the planet (like the Shoemaker-Levy 9 comet), or a moon of the planet, or they are tossed into the inner solar system. Short period comets – option 2 • Have a close encounter with Neptune. • This can toss it into an orbit which goes from Neptune to the orbit of the terrestrial planets (like Earth). • Or, it could become a Centaur for awhile. Meteor Showers • Occur when the earth passes through the orbit of a short period comet Long period comets • • • • Orbits are millions of years. None come from interstellar space. These come from the Oort cloud. Collisions are a possibility, but more than likely these orbits started this way (we will see how later). • Although collisions are possible, they are not likely. There is just too much space out there. • The only other way to go from circular orbits to extremely elliptical ones is to have perturbations from passing stars (stars that occasionally get within about 0.5 light years from the sun). Structure of comets (APOD – Bradfield + LINEAR) Hale Bopp + Andromeda (APOD) Nucleus – comet Borrelly (APOD) Deep Impact – Temple 1 After impact Wild 2 (Stardust) Halley’s nucleus (APOD + Giotto) • 6 m deep of material thrown off each pass • Cause of the Orionids meteor shower. • 15 km in size, Density 25% of water. Very dark nucleus. apart What is the fate of comets? • Eventually, comets eject all their icy material near their surfaces. • When this happens, they look more like metal poor asteroids. • So, they stop being “comets” like we know them, and are just a floating rock pile with some ice in the center quietly floating through the solar system in its orbit. Aurora Satellites • https://www.youtube.com/watch?v=x8YDR nZzyNs • https://www.youtube.com/watch?v=dfGGA _apXic conclusion • Comets are mostly loosely held together piles of ice and rock (“dirty snowballs”). • Comets light up when they get inside the orbit of Mars because they eject several meters of ice off their surfaces through jets. • Short period comets probably come from the Kuiper Belt. • Long period comes probably are the Oort Cloud.