Planet Highlights Mercury Mercury Highest Density Thinnest Atmosphere

Planet Highlights

Mercury

Mercury • Highest Density • Thinnest Atmosphere • Highest Temperature and Greatest Temperature Range • Messenger will fly by in 2011 • Surface is similar to the moon, very cratered, old

Venus

Venus • It’s day is longer than its year • Still volcanically active and covered with large lava flows • It has no moons • Atmosphere is mostly Carbon Dioxide, which causes a large Greenhouse Effect, raising its temperature

Venus: Earth’s Twin • Similar in size • Similar density • Young, volcanically active surface • Probably used to have water that boiled away

Mars

Exploration of Mars • Has been explored more than any other planet: – Mariner 4 visited for the first time in 1965 – Landers include Mars 2, Viking, Pathfinder, Spirit, and Opportunity – 3 orbiters are currently in orbit We have learned a lot about the surface of Mars as a result

Surface of Mars • Largest Mountain/Volcano in Solar System: Olympus Mons

Surface of Mars • Rocky • Evidence of erosion possibly by liquid water: Dry river beds and canyons • Volcanoes and lava flows • Red Planet

Largest Canyon in solar system • Would stretch from New York to Los Angeles on earth

Moons of Mars • 2 Moons – Phobos Deimos

Other Mars Facts • Very thin atmosphere • Permanent polar ice caps made of water and carbon dioxide

Asteroid Belt • The region between Mars and Jupiter contains irregularly shaped rocky objects called asteroids.

Asteroids • Asteroids are probably left over material from a planet that never formed. • They range in size from 1000 km to the size of a pebble. • There are 26 large ones and millions of smaller ones, although most of the asteroid belt is empty space.

Jupiter • Gas Giant: No solid surface, it’s gases just get more dense. • Under the gases is a liquid metallic core (at high temperatures and pressures the hydrogen becomes a liquid with ionized protons and electrons that conduct electricity like a metal) • Made mostly of Hydrogen and Helium • Rocky core 10 -15 times the mass of earth

Jupiter • Lots of images from Hubble • Flyby in 1973 by Pioneer, Voyager • Orbited for 8 years by Galileo

Jupiter Facts • Has the Great Red Spot- giant storm in its gases • Has faint rings • Has 63 moons, 4 very large ones • Was hit by a comet in 1994 • So big all of the other planets would fit inside it (diameter is 11 times that of earth)

Saturn • Gas Giant containing a gas surface of mostly Hydrogen and Helium, a liquid hydrogen metal outer core, and a rocky inner core • Has large, prominent rings with spaces between them • Cassini is orbiting since 2004 • Voyager and Pioneer visited • 34 moons

Saturn • Saturn has such a low density it would float in water!

Titan- Saturn’s Moon • Larger than Mercury and Pluto • Second largest moon in solar system • Has a planet-like atmosphere • Has places on it that look like liquid-filled lakes (probably not water)

Titan • We sent Cassini THROUGH Saturn’s rings to orbit Titan. Then we dropped Huygens onto the surface of Titan. It landed with the help of 3 parachutes to slow it down from 12, 000 mph • Found mud, rock, and liquid

Uranus • Gas Giant: It’s atmosphere has Hydrogen and Helium, but it’s interior is rocky and icy. • Only visited once by Voyager • Rotates on it’s side with its south pole facing the sun • 11 rings • 27 moons

Uranus

Neptune • Sometimes its orbit crosses that of Pluto, making it farther away from the sun than Pluto • Visited only once by Voyager • Gas Giant with a Gas surface of hydrogen and helium, and then a rocky, icy core • 13 Moons and faint rings

Neptune

Kuiper Belt • Region beyond Neptune with small, icy objects that are the source of comets • Sedna and other small planetoids are located here