Touring Our Solar System Chapter 23 Earth and

Touring Our Solar System Chapter 23 Earth and Space Science

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.

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.

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.

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 _________________

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

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

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 they grew into planets.

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.

23. 2 The Terrestrial Planets • The four inner-most planets are called the terrestrial planets because they are made of rock. • _______, _______, and ________.

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

23. 2 The Terrestrial Planets • ________: The Veiled Planet • 2 nd 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

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% CO 2 in atmosphere

23. 2 The Terrestrial Planets ______: The Red Planet • Atmosphere: 1% the density of Earth’s. • Mostly _____ • Polar caps – mostly of water and CO 2 • Has dust storms and hurricane-force winds up to 270 km/hr. • Very cold – thin atmosphere

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 – ____________

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

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

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

23. 3 The Outer Planets (and Pluto) • Jupiter’s Rings • Discovered by Voyager I - fine, dark particles

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

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

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. 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

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

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.

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.

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

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

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.

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

23. 4 Minor Members of the Solar System • ___________ – 60 or more meteors seen in an hour • Perseid meteor shower – around Aug. 12 th each year • _____________ – a meteoroid that actually reaches the Earth. • Meteor Crater in Arizona –