Our Solar System & Exoplanets(Chapter 15)

Student Learning Objectives

• Identify and locate objects in our solar system

• Describe planet

formation processes

• Explain how exoplanets are found.

What are the main characteristics of our solar system?

All of the objects in our solar system formed at about the same time.

 4.5 Billion Years Ago

Objects in our solar system revolve and rotate counterclockwise as viewed from above

Venus rotates backwards

Uranus rotates on its side

Our Solar System

Our solar system has one star, the Sun.

Planets orbit the Sun. Moons orbit the planets.Dwarf planets orbit the Sun.Asteroids and Comets orbit the Sun.

Practice

1) How many stars are within our solar system?

2) How many moons do you think there are in our solar system?

3) List the planets in order from the Sun outward.

What is the process of planet formation?

Planets form in a disk of rotating gas and dust surrounding a forming star.

Solar Nebula Theory

Condensation

Accretion

Planetesimals

Proto-planets

Planets

Two Zones develop during the condensation phase.

Near & Far from SunMetals

IronSilicates

Far from Sun

Ices

WaterMethaneAmmonia

OriginalCloud

SpinsFasterAs It

Contracts

FlattenedDiskOf

Planets

2nd Stage Planet Formation

Migration

Differentiation

Atmosphere

Clearing of the Nebula

Bombardment

Atmosphere & Leftovers

Atmospheres form on some solid planets.

Outgassing/VolcanismGravityComet Impacts

Large planets capture atmosphere.

Leftover planetesimals become moons, asteroids, & comets.

Phobos

Practice

1) Why is the motion of objects in our solar system relatively uniform?

2) What determines the two zones?

3) What two factors determine whether a planet has an atmosphere?

4) Why does Earth have an abundance of oxygen?

How do astronomers search for extra-solar planets?

Gravity

Eclipses

Microlensing

Direct Imaging

http://kepler.nasa.gov/

http://planetquest.jpl.nasa.gov/ (number of exoplanets)

Gravitational Wobble

Gravity causes a star to wobble.The wobble causes a Doppler Effect.

Transits

Transits cause some starlight to be eclipsed.

http://kepler.nasa.gov/Mission/discoveries/

Microlensing

Light follows the curvature of space.

Direct ImagingSpace telescopes "see" planets

Gemini Planet Imager

Beta Pictoris b is a giant planet – several times larger than Jupiter – and is approximately ten million years old. (January 2014)

Direct Image

of an Exo-planet 155 LY Away

by David Dickinson May 14, 2014

1st Habitable Zone planet observed (2010)

Question: What is the Habitable Zone?

Kepler 11

NASA's

Kepler Mission Discovers a World Orbiting

2 Stars

(September 2011)

Kepler 16

NASA's Kepler TelescopeDiscovers First Earth-Size Planet in Habitable Zone

(April 2014)

Practice

Astronomers are searching for planets around stars like our Sun.

Why?