Class Notes (904,110)
CA (538,125)
UTSG (45,701)
AST (668)
AST101H1 (417)
Lecture

Chapter 7

12 Pages
118 Views

Department
Astronomy & Astrophysics
Course Code
AST101H1
Professor
Clifford Orwin

This preview shows pages 1-3. Sign up to view the full 12 pages of the document.
Chapter 7: Our Planetary System
Oct/19/2010
7.1 Studying the Solar System
Comparative Planetology: The study of the solar system by examining and
understanding the similarities and differences among worlds.
The essence of comparative Planetology lies in idea that we can learn more about
individual world, including Earth, by studying it in context of other objects in solar
system.
Four Major Clues As To How Solar System Formed: (1) Large bodies in the solar
system have orderly motions (2) Planets fall into two major categories [1] small, rocky,
terrestrial planets [2] large, hydrogen-rich jovian planets i.e. Uranus, Saturn (3)
Swarms of asteroids and comets populate the solar system in the asteroid belt [btw. Mars
and Jupiter], the Kuiper Belt [beyond Neptune’s orbit], and Oort Cloud [spherical
region in distant solar system encompassing Kuiper and Asteroid Belts.] (4) Several
notable exceptions to the above stated trends stand out Ex. Uranus’ unusual axis tilts.
The Sun
Radius: 696,000 km = 108REarth
Mass: 333,000MEarth
Composition (by mass): 98% hydrogen and helium, 2% other elements.
More than a thousand times as massive as everything else in solar system combined.
Roiling sea of hot (apprx. 5800K, or 5500 degrees Celsius) hydrogen and helium gas.
Surface is speckled with sunspots that are slightly cooler than their surroundings.
Fusion transforms 600 million tons of Sun’s hydrogen into 596 million tons o’ He. 
Missing” 4 million is converted into energy according to E = mc2.
Gravity governs orbits of other planets.
Heat is primary influence on temps o’ planetary surfaces and atmosphere.
www.notesolution.com
Charged particles flowing outward from Sun (Solar wind) help shape planetary magnetic
field and can influence planetary atmospheres.
Mercury
Average distance from the sun: 0.39 AU
Radius: 2440 km = 0.38REarth
Mass: 0.055MEarth
Composition: Rocks, metals
Average Surface Temperatures: 700 K (day), 100 K (night)
Moons: 0
Smallest of eight official planets
Desolate, cratered world with no active volcanoes, no wind, no rain, and no life.
Rotates once every 58.6 days Rotates exactly three times for every two of its 87.9 day
orbits of the Sun.
Shows evidence of past geological activity Plains created by ancient lava flows and
tall, steep cliffs that run hundreds of km in length. These cliffs, though, may be
wrinkles from an episode of “planetary shrinking.
Mercury’s high density indicates that it has an iron core.
Venus
Av dist from sun: 0.72 AU
Radius: 6051 km = 0.95REarth
Mass: 0.82MEarth
Composition: Rocks, metals
Average Surface Temp: 740 K
Moons: 0
www.notesolution.com
Rotates very slowly and opposite direction of Earth --? Days and nights very long and
Sun rises in west and sets in east instead of rising in east and setting in west.
Surface completely hidden from view by dense CO2 clouds.
Extreme greenhouse effect bakes Venus’s surface to 470 degrees Celsius trapping heat so
effectively that it offers no relief.
Thick atmosphere bears down on surface with pressure equivalent to that nearly a km
beneath ocean’s surface on Earth.
Venus has mountains, valleys, and craters, and shows many signs of past of present
volcanic activity.
Earth
Average distance from sun: 1.00 AU
Radius: 6378 km = 1REarth
Mass: 1.00MEarth
Average Density: 5.52 g/cm3
Composition: rocks, metals
Average surface temperature: 290K
Moons: 1
Only planet in solar system with oxygen to breath, ozone to shield surface from deadly
solar radiation, abundant surface water to nurture life.
Temperature pleasant b/c Earth’s atmosphere contains just enough carbon dioxide and
water vapour to maintain moderate greenhouse effect.
Oceans cover 3/4ths of it.
White clouds scattered above surface
Polar caps white with snow and ice.
Moon is largest relative to size of planet it orbits Hypothesis hold moon’s creation b/c
giant impact early in Earth’s history.
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Chapter 7: Our Planetary System Oct192010 7.1 Studying the Solar System Comparative Planetology: The study of the solar system by examining and understanding the similarities and differences among worlds. The essence of comparative Planetology lies in idea that we can learn more about individual world, including Earth, by studying it in context of other objects in solar system. Four Major Clues As To How Solar System Formed: (1) Large bodies in the solar system have orderly motions (2) Planets fall into two major categories [1] small, rocky, terrestrial planets [2] large, hydrogen-rich jovian planets i.e. Uranus, Saturn (3) Swarms of asteroids and comets populate the solar system in the asteroid belt [btw. Mars and Jupiter], the Kuiper Belt [beyond Neptunes orbit], and Oort Cloud [spherical region in distant solar system encompassing Kuiper and Asteroid Belts.] (4) Several notable exceptions to the above stated trends stand out Ex. Uranus unusual axis tilts. The Sun Radius: 696,000 km = 108R Earth Mass: 333,000M Earth Composition (by mass): 98% hydrogen and helium, 2% other elements. More than a thousand times as massive as everything else in solar system combined. Roiling sea of hot (apprx. 5800K, or 5500 degrees Celsius) hydrogen and helium gas. Surface is speckled with sunspots that are slightly cooler than their surroundings. Fusion transforms 600 million tons of Suns hydrogen into 596 million tons o He. Missing 4 million is converted into energy according to E = mc .2 Gravity governs orbits of other planets. Heat is primary influence on temps o planetary surfaces and atmosphere. www.notesolution.com Charged particles flowing outward from Sun (Solar wind) help shape planetary magnetic field and can influence planetary atmospheres. Mercury Average distance from the sun: 0.39 AU Radius: 2440 km = 0.38R Earth Mass: 0.055M Earth Composition: Rocks, metals Average Surface Temperatures: 700 K (day), 100 K (night) Moons: 0 Smallest of eight official planets Desolate, cratered world with no active volcanoes, no wind, no rain, and no life. Rotates once every 58.6 days Rotates exactly three times for every two of its 87.9 day orbits of the Sun. Shows evidence of past geological activity Plains created by ancient lava flows and tall, steep cliffs that run hundreds of km in length. These cliffs, though, may be wrinkles from an episode of planetary shrinking. Mercurys high density indicates that it has an iron core. Venus Av dist from sun: 0.72 AU Radius: 6051 km = 0.95R Earth Mass: 0.82M Earth Composition: Rocks, metals Average Surface Temp: 740 K Moons: 0 www.notesolution.com
More Less
Unlock Document


Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit