Our solar system consists of the Sun and eight planets This shows the relative sizes of the sun and the planets

Relative Distances of the Planets from the Sun

The Sun The star at the center of the Solar System All the planets revolve around it So large, over one million Earths could fit inside it 1 million km wide ball of burning gas The surface temperature is 5500ºC, The core reaches a sweltering 15.6 million ºC

Variations in the Sun's magnetic field cause huge jets or loops of stellar material to shoot out into space, this one is called a Coronal loop Earth is inserted only to show scale of solar flares

The Rocky Inner Planets MercuryVenus Earth Mars Also called the "terrestrial" planets because of their proximity and similarity to Earth

Closest planet to the Sun 2nd smallest planet widest temperature variation of any planet, from -170°C at night to 350°C during the day No moon Negligible atmosphere Orbital period is 88 days Mercury

Mercury is smaller than two moons, Ganymede of Jupiter and Titan of Saturn

Second planet from the sun No moon Orbital period Earth days Rotational period Earth days!! Atmosphere mainly carbon dioxide 90 times Earth pressure Temperature 480ºC

Third Planet from the sun Third Planet from the sun One moon One moon Average temp 22° C Average temp 22° C Atmosphere mainly nitrogen with oxygen and carbon dioxide Atmosphere mainly nitrogen with oxygen and carbon dioxide Largest inner planet

Moon – Physical Characteristics We see the moon only as a result of the ALBEDO – reflectivity from the sun Moon has NO ATMOSPHERE and NO GRAVITY NO EROSION – no running water, no wind –Meteorite impacts that happened long ago remain just as they were when they were hit.

Moon – Regional Features Highlands – light in color, mountainous, and have several craters. Maria – dark in color, are very smooth plains. Lower in elevation than the highlands Impact craters

How did the moon form? 3 theories –Capture Theory An object was flying by earth when it was first forming, and earth’s gravitational pull brought it into orbit. –Nothing to slow down the object to allow it to be “captured” –Would be a greater difference in composition if this were the case –Simultaneous Formation Theory Moon and Earth formed at the same time from the same materials after the Big Bang. –Less iron on moon than Earth so probably not what happened –Impact Theory: most likely possibility Mars sized object – knocked a piece of Earth off, and combined with pieces of the object to become the moon. –Heat from the impact would have evaporated any water present in the minerals…and therefore the minerals found on the moon are water deficient.

Phases of the Moon

Names of the Phases of the Moon

Parts of an Eclipse;Types of Eclipses Umbra: inner part of the shadow Penumbra: outer part of the shadow Lunar eclipse: occurs when moon passes into Earth’s umbra Earth casts shadow on the moon - Can only occur at full moon phase - Moon remains visible, but has dusky red or coppery color - At least 1 total lunar eclipse occurs every year - People within the umbra will see a total lunar eclipse - People within the penumbra will see a partial lunar eclipse

Parts of an Eclipse Types of Eclipses  SOLAR ECLIPSE – Moon passes between the sun and the Earth  Note how much smaller the umbra (inner part of the shadow) is with a solar eclipse, as compared with the lunar eclipse.

Annular Eclipse Occurs during a solar eclipse when the moon is in apogee (furthest from the earth) Perigee is when the moon is closest to Earth The moon appears smaller as seen from earth Therefore it will not completely block the disk of the sun.

Mars 4 th planet4 th planet from the sun Two moons, Phobos and Deimos Orbital period Earth days Rotational period - 24 Earth hours 37 minutes Thin Carbon Dioxide atmosphere Temperature -55°C Phobos Deimos

Asteroid Belt Asteroids - rocky and metallic objects that orbit the Sun but are too small to be considered planets Most are contained within a belt that exists between the orbits of Mars and Jupiter Some have orbits that cross Earth's path and some have even hit the Earth in times past Asteroids that are on a collision course with Earth are called meteoroids

Other cosmic bodies Meteor: a streak of light produced by a meteorite or parts of a comet burning up in Earth’s atmosphere Meteorite: a meteoroid or part of it that strikes the surface of the Earth (usually pieces of asteroids) Comet: small icy body made of ice and rock that orbits the sun –1 – 10 km in diameter –In two clusters: The Kuiper belt and the Oort cloud –Has a head that becomes brighter as it approaches the sun –May have one or more tails Tails always point away from the sun because of radiation, particles, and ions coming from the sun

Barringer Meteor Crater, Arizona

The Jovian Planets JupiterSaturn Uranus Neptune Named because of their gigantic Jupiter-like appearance Also called the Gas Giants

Jupiter Gas Giant – composed almost entirely of gas Great Red Spot – largest storm in the solar system More than 39 moons Larger than all other planets combined Atmosphere mainly hydrogen and helium Orbital period 4,332.6 Earth days Temperature is -123ºC at the surface 20,000ºC at the core

Jupiter Jupiter has more than 39 moons. The largest four are called the Galilean moons. Io Callisto Ganymede Europa The Jupiter System

Second largest planet in the solar systemSecond largest planet in the solar system Saturn's density is so small that it would float on water - if there were an ocean large enough!Saturn's density is so small that it would float on water - if there were an ocean large enough! Atmosphere mainly hydrogen and heliumAtmosphere mainly hydrogen and helium Orbital period 10,750 Earth days, or 29.5 Earth years Orbital period 10,750 Earth days, or 29.5 Earth years Rotational period - 10 Earth hrs 14 minsRotational period - 10 Earth hrs 14 mins

The Saturn System Dione Titan Rhea Epimetheus Saturn has more than 25 moons Enceladus Mimas Iapetus Tethys Saturn

Uranus Orbital period 30,707 Earth days or 84 yrs Rotational period 17 Earth hours 12 mins More than 21 moons Atmosphere mostly Hydrogen, helium, & methane The only planet to spin on its side, so nights and days are 42 years long

The Uranian System Ariel Uranus Titania – the largest moon Miranda Umbriel Oberon

Neptune 4 th largest planet More than 11 moons, largest is Triton Atmosphere of Hydrogen, helium and methane Orbital period - 60,202 Earth days or Earth years Rotational period - 16 Earth hours 7 mins Has the fastest winds in the solar system with speeds of 2000 km per hour

Neptune and Triton

Pluto smallest and most distant planet in the solar system half the size of Earth's Moon some astronomers argue that Pluto isn't a planet at all, but a giant asteroid. Orbital period, 90,803 Earth days or 248 yrs Rotational period – 153 hrs Thin Nitrogen atmosphere with CO2 and methane Temp -220ºC One moon, Charon

Pluto Charon