Nothing travels faster than the speed of light. 186,000 miles a second 300,000,000 meters per second 700 million miles an hour. For scale, the distance from the Earth to the Moon is about 239,000 miles. The distance light can travel in a year is called a "light year." The light year is one of the basic measures of distance for astronomy. Nothing travels faster than the speed of light.

Distance Because space is so vast, astronomers have a created different unit for measuring the distances in space known as an astronomical unit. This is the distance from the Sun to the Earth. Earth is 93million miles from Sun (150million km) 1 AU (astronomical unit) http://www.northern-stars.com/solar_system_distance_scal.htm

AU’s Mercury .38 Venus- .72 Earth- 1.0 Mars- 1.5 Jupiter- 5.2 Saturn- 9.5 Uranus- 19.2 Neptune- 30.0 Pluto- 39.4 Scale solar system 1AU= 1m (earth 1m away from sun)

General Characteristics of the Solar System Planetary orbits and rotation planet and satellite orbits are in a common plane nearly all planet and satellite orbital and rotation motions are in the same direction

What is a planet? The definition of planet set in 2006 by the International Astronomical Union (IAU) states that in the Solar System a planet is a celestial body that: is in orbit around the Sun, has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and has "cleared the neighborhood" around its orbit.

Nearly all planet and satellite orbital and rotation motions are in the same direction

General Characteristics of the Solar System Terrestrial planets- small, composed of rock and metallic elements (metals) Jovian planets- large, composed of gases and frozen compounds

4 Terrestrial Planets The Inner Planets Mercury, Venus, Earth, Mars Rocky and metallic Small No rings Very few moons

MERCURY closest to our Sun small, rocky planet - much like our Moon It is covered with craters and has changed very little from when it was first formed One side HOT: 800o F Other side COLD: -275o C MERCURY

Mercury Facts •Average Distance From Sun Astronomical Units: 0.387 Kilometers: 57,000,000 Miles: 36,000,000 Astronomical Units: 0.387 Length of Day: 58 days 15 hours 30 minutes Length of Year: 87.97 days Average Orbital Speed Kilometers/Second: 47.89 Miles/Second: 29.76 Number of Known Satellites: 0

VENUS Intense heat and volcanic activity. Similar in structure and size to Earth Venus' thick, toxic atmosphere traps heat in a runaway "greenhouse effect."

VENUS Average Distance From Sun Kilometers: 108,200,000 Miles: 67,000,000 Astronomical Units: 0.723 Length of Year: 224.7 days Length of Day: 243 days Number of Known Satellites: 0

EARTH Only planet known to have life Only planet not named after a Greek/Roman god

Earth Average Distance From Sun Kilometers: 149,600,000 Miles: 93,000,000 Astronomical Units: 1.000 Length of Year: 365.26 days Length of Day: 23 hours 56 minutes 4 seconds Volume (Earth=1): 1.000 Number of Known Satellites: 1

The Asteroid Belt Separates Inner and Outer planets Asteroids left-overs from the formation of the Solar System. While some have suggested that they are the remains of a proto-planet that was destroyed in a massive collision long ago, the prevailing view is that asteroids are leftover rocky matter that never successfully coalesced into a planet.

4 Jovian Planets The Outer Planets Jupiter, Saturn, Uranus, Neptune Gases & frozen gases Very large All have rings Many moons

JUPITER

Jupiter 5th planet (1st outer planet) 9.84 hours to rotate 4,333 days to revolve (12 earth years) 66 moons 4 Rings Largest Planet Atmosphere - Hydrogen, Helium, Oxygen, Nitrogen and Methane

Saturn 6th planet 10.2 hours to rotate 10, 759 days to revolve (29 earth years) 62 moons 23 Rings Atmosphere Hydrogen and Helium

Uranus 7th planet 17.9 hours to rotate 30,688 days to revolve 27 moons (84 earth years) 27 moons 13 Rings Atmosphere: Methane, Hydrogen and Helium Tilted on its side

Neptune 8th planet 19 hours to rotate 60,181 days to revolve (164.8 earth years) 13 moons 9 Rings Methane atmosphere gives it bluish color

Is Pluto a Planet? Dwarf planet From its time of discovery in 1930 to 2006 it was considered to be the ninth planet in the solar system, but because additional objects have been discovered including Eris which is 27% more massive, the IAU reclassified Pluto and the other objects as dwarf planets. The New Horizons spacecraft was launched on January 16, 2006 and will make its closest approach to Pluto on July 14, 2015. This mission will provide an increased amount of information about this peculiar dwarf planet. Unlike planets, dwarf planets lack the gravitational muscle to sweep up or scatter objects near their orbits. They end up orbiting the sun in zones of similar objects such as the asteroid and Kuiper belts.

How far is the Moon from Earth? The moon is 30 Earth’s away

COMETS A comet is an icy ball that releases gas or dust. They are often compared to dirty snowballs.

COMETS Halley's Comet

ASTEROIDS Asteroids are rocky, airless worlds that orbit our sun too small to be called planets Tens of thousands of these "minor planets" are gathered in the main asteroid belt, a vast doughnut-shaped ring between the orbits of Mars and Jupiter. Asteroids that pass close to Earth are called Near-Earth Objects (NEOs).

METEORIODS Little chunks of rock and debris in space are called meteoroids. They become meteors -- or shooting stars -- when they fall through a planet's atmosphere Pieces that survive the journey and hit the ground are called meteorites.

KUIPIER BELT and OORT CLOUD The Kuiper Belt is a disc-shaped region of icy objects beyond the orbit of Neptune -- billions of kilometers from our sun. Oort cloud is a sphere of ice dwarfs and ice particles that surround our solar system. Pluto and Eris are the best known of these icy worlds. There may be hundreds more of these ice dwarfs out there. The Kuiper Belt and even more distant Oort Cloud are believed to be the home of comets that orbit our sun.

General Characteristics of the Solar System Planetary orbits and rotation planet and satellite orbits are in a common plane nearly all planet and satellite orbital and rotation motions are in the same direction

How do we classify stars? Size Temperature and Color Brightness

Stars have Different colors which indicate different temperatures Temperature and color The color of the star is dependent on the temp of the star. Red – coolest stars Blue – hottest stars Order from coolest to hottest Red, red-orange, yellow, white, blue 3000K 6000K 30,000K Stars have Different colors which indicate different temperatures

Temperature and Color

Size Giants/supergiants- large and very large stars. Many of these are very far away White dwarfs- very small stars – about the size of the Earth Neutron stars- even smaller stars – only 20 km in diameter. Medium sized stars- many stars this size. The size of our Sun.

Binary Stars are used to determine the mass of the star. Binary star systems contain two stars that orbit around their common center of mass. Many of the stars in our galaxy are part of a binary system. Binary Stars are used to determine the mass of the star.

How do we measure stars? Parallax- the apparent change in position of an object when you look at it from different places.

Parallax The closer the star is to Earth, the larger the shift will be

The movement would be too small to measure accurately. Parallax Only good for measuring stars close to us. Not farther than 1000 light years away. Why? The movement would be too small to measure accurately.