Touring Our Solar System

1. Touring Our Solar System Chapter 23 Earth and Space Science

2. 23.1 The Solar System • 99.85 % of the mass of our solar system is contained within the ___ • The Planets make up 0.15% of the mass. • Order of the planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

3. 23.1 The Solar System • All the planets orbit the sun in ________________ _______________ • All travel in the same direction • The planets are split into two groups – the ______________ and the _______ planets. • Size is the most obvious difference between the two groups. • Density, chemical makeup, and rate of rotation are other ways in which the two groups differ.

4. 23.1 The Solar System • Pg. 646, figure 2 • Interiors of the Planets • 3 groups: _______ _________ ________ • Gases: Hydrogen and Helium • Rocks: iron and silicate minerals • Ices: ammonia, methane, carbon dioxide, water. • The terrestrial planets are mostly rocky, little gas, the outer planets are mostly gas.

5. 23.1 The Solar System • Atmospheres of the Planets • ___________________ – thick atmospheres – hydrogen, helium, methane, ammonia • ___________________ – meager atmospheres - lighter gases • In order for a planet to have an atmosphere it must have enough gravitational pull to keep the gas molecules from reaching the _________________________________

6. 23.1 The Solar System • Formation of the Solar System • ________________– a cloud of dust and gas in space • Usually consists of 92% H, 7% He, and less than 1% all other gases. • These nebula start to rotate and contract, then speed up

7. 23.1 The Solar System • __________________________ – the sun and planets formed from a rotating disk of dust and gases. • As it sped up, the center flattened out, matter condensed, and the sun was formed • Pg. 647, figure 3

8. 23.1 The Solar System • __________________________ – small irregularly shaped bodies that formed from solid bits of matter that collided in space. • As the collisions continued the planetesimals got bigger, and more gravity attracted more matter and the they grew into planets.

9. 23.1 The Solar System • Inner planets were too close to the sun for the ices to solidify – therefore they were formed from materials with high melting points. • For the outer planets, they were cold enough for ices of water and other substances to form. Both solid materials and gases.

10. 23.2 The Terrestrial Planets • The four inner-most planets are called the terrestrial planets because they are made of rock. • _____________, _________, _______, and _______________.

11. 23.2 The Terrestrial Planets • _____________: The Innermost Planet • Smallest planet – hardly larger than Earth’s moon • No atmosphere • Cratered highlands and smooth terrain • 1 rotation = ______ Earth days • Nighttime temps = -173ôC • Noontime temps = 427 ôC • Has the greatest temp extremes of any planet

12. 23.2 The Terrestrial Planets • ________________: The Veiled Planet • 2nd in brilliance to the ________ in the night sky. • Revolution = ______ Earth-days • Called “__________________” – similar in size, density, mass, and location in solar system • Covered with thick clouds – hard to see surface

13. 23.2 The Terrestrial Planets • ____________ spacecraft reached the surface and gave us our main information. • Basaltic volcanism • Tectonic activity • 80% covered by lava flows • 8% highlands • ___________________________– temp 475ôC • 97% CO2 in atmosphere

14. 23.2 The Terrestrial Planets ____________: The Red Planet • Atmosphere: 1% the density of Earth’s. • Mostly _________ • Polar caps – mostly of water and CO2 • Has dust storms and hurricane-force winds up to 270 km/hr. • Very cold – thin atmosphere

15. 23.2 The Terrestrial Planets • Mars’ surface features • _____________________ (1971) • Large, inactive volcanoes • Largest – _____________________ • Size of Ohio, 23 km high • Cratered • Large canyons – larger than the Grand Canyon • Largest – ________________________

16. 23.2 The Terrestrial Planets • Water on Mars? • Drainage patterns similar to Earth • Opportunity – evaporite minerals, geologic formations assoc. with water • Viking – ancient islands • Mars Global Surveyor – groundwater • Temp range: -70ôC to -100ôC

17. 23.3 The Outer Planets (and Pluto) • ___________________: Giant Among Planets • 1/800 the mass of the sun • 2.5 more massive than all the other planets and moons. • Quickest rotation: 10-Earth hours • ______________________- cyclonic storm • Not made up entirely of gas • Liquid hydrogen, liquid metallic hydrogen, • Rocky, metallic core

18. 23.3 The Outer Planets (and Pluto) • Hydrogen-helium atmosphere • Wind system that generated light and dark colored bands. • Jupiter’s moons – 63 • 4 largest – _____, ________________, ________________, ______________ • Discovered by Galileo in 1610 • Io is volcanically active

19. 23.3 The Outer Planets (and Pluto) • Jupiter’s Rings • Discovered by Voyager I - fine, dark particles

20. 23.3 The Outer Planets (and Pluto) • ________________: The Elegant Planet • 29.46 Earth-years to make one revolution • Extensive ring system • Discovered by Galileo in 1610. • Visited by Voyager I & II in 1980 and 1981

21. 23.3 The Outer Planets (and Pluto) • Winds up to 1500 km/hr • Cyclonic storms within the atmosphere • Discovered 11 additional moons • Rings were very complex • Has 56 moons • Largest – ________________ – has an atmosphere of its own

22. 23.3 The Outer Planets (and Pluto) • Enceladas – volcanically active • Liquid water geysers • Saturn’s Rings • made of _________________ • 2 categories, based on particle density

23. 23.3 The Outer Planets (and Pluto) • ______________: The Sideways Planet • Rotates on its side • Has a ring system • 13 moons • Largest is ____________________ • Winds exceeding 1000 km/hr • ______________________________ • Cirrus-like clouds - methane

24. 23.3 The Outer Planets (and Pluto) • __________________: Dwarf Planet • Has not cleared the area around its orbit, therefore, it is not a planet • Many other dwarf planets occur, some larger than Pluto, some smaller • Has a moon, Charon

25. 23.4 Minor Members of the Solar System • In February 2001, The NEAR Shoemaker made history by becoming the first spacecraft to land on the asteroid, Eros. • _________________________ – small, rocky bodies that orbit the sun. • They are larger than 10 meters in dia. • Most lie in the ___________________ between Mars and Jupiter.

26. 23.4 Minor Members of the Solar System • Asteroids are irregularly shaped • Scientists believe they are fragments of a previous planet that was destroyed. • _____________________ – pieces of rocky and metallic minerals held together by frozen water, ammonia, methane, carbon dioxide, carbon monoxide.

27. 23.4 Minor Members of the Solar System • Take hundreds of thousands of years to complete a single orbit around the sun. • __________________ – head of the comet • Has a nucleus • As comets approach the sun they develop a tail that extends behind as gases are evaporated

28. 23.4 Minor Members of the Solar System • __________________ contains comets with a short orbital period. • Located beyond _______________ • They lie roughly in the same plane as the planets • ____________________ – contains comets with a long orbital period. • Do not lie in the same plane as the planets

29. 23.4 Minor Members of the Solar System • __________________________ – orbital period of 76 years. • was here in 1910 and 1986 • Will return in 2061 • _______________________ – small, solid particle that travels through space.

30. 23.4 Minor Members of the Solar System • Originate in one of three areas • 1. interplanetary debris • 2. material from the asteroid belt • 3. the solid remains of comets that once traveled near Earth’s orbit • ____________________ - meteoroids that enter the Earth’s atmosphere

31. 23.4 Minor Members of the Solar System • _____________________ – 60 or more meteors seen in an hour • Perseid meteor shower – around Aug. 12th each year • _________________________ – a meteoroid that actually reaches the Earth. • Meteor Crater in Arizona –