Our Solar Our Solar SystemSystem

A sleeping puppy production

Questions/Understandings

• ???: What happened after the Big Bang that formed everything in our solar system?

• Understanding: There are both large and small celestial bodies in our solar system including the sun, planets, moons, asteroids, comets and meteoroids.

A theory of the beginning….

Scientists believe that the solar system was formed approximately 4.6 billion years ago when a cloud of gas and dust (nebula) in space was disturbed, by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust.

Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula.

Just like a dancer that spins faster as she pulls in her arms, the cloud began to spin as it collapsed. Eventually, the cloud grew hotter and denser in the center, with a disk of gas and dust surrounding it that was hot in the center but cool at the edges.

Solar Nebula

As the disk got thinner and thinner, particles began to stick together and form clumps. Some clumps got bigger, as particles and

small clumps stuck to them, forming planets and moons.

At the center of the cloud, where planets like Earth formed, only rocky material could

stand the great heat. Icy matter settled in the outer region of the disk along with rocky material, where the giant planets like Jupiter formed. As the cloud fell in, the center got so hot that it became a star, the Sun, and blew most of the gas and dust of the new solar system with a strong stellar wind.

By studying meteorites, which are thought to be

left over from this early phase of the solar system, scientists have found that the solar

system is about 4.6 billion years old!

A little about our Solar System

• As you know, planets are part of our solar system.

Comets, asteroids, meteoroids, and the moons are part of the solar system, too. They all orbit around a star we call the sun.

• It's all held together by gravity.  

• The planets are divided into two groups:

• the four Inner planets Mercury, Venus, Earth and Mars

• the four Outer planets Jupiter, Saturn, Uranus, Neptune

Tiny Rocky Bodies

• Meteoroid: tiny rocky body in our solar system

• Meteor: a meteoroid that enters Earth’s atmosphere and burns up. Meteor shower, also known as a shooting star.

• Meteorite: part of a meteoroid that survives the trip through Earth’s atmosphere and ends up on the surface of the earth.

MERCURY

• The diameter of Mercury is 3,031 miles.

• It takes the planet 58.6 days to rotate completely 360 degrees.

• It takes 88 Earth days for Mercury to orbit the sun.

• Mercury only weighs 5.5% of what earth weighs.

• Mercury’s diameter is 38% of what the earth’s diameter is.

More about Mercury

Mercury is the closest planet to the sun. Because Mercury is so close to the sun (and the sun's glare) it is difficult to spot from Earth.

Mercury's gravity is less than half what we have on Earth, so Mercury would not be able to hold onto an atmosphere even if the sun had not blown its away.

Since there's no atmosphere (which on Earth acts like a warm blanket) temperatures on Mercury go crazy. It can be a scorching 750 degrees Fahrenheit during the day, and minus 320 at night!

VENUS

• The Diameter of Venus is 7,521 miles.

• It takes 243 days to rotate 360 degrees completely.

• It Takes 225 Earth days to orbit the sun.

• It only has 82 % of the mass earth has

• Its diameter is about 95% of earths.

• It is a 30 percent closer to the sun that the earth.

More fun facts about Venus• The second planet from the sun

bakes under twice as much solar radiation as Earth. Venus reaches temperatures of 895 degrees Fahrenheit!

• The thick clouds around Venus rotate much faster than the planet itself -- once every four days. Not counting the moon, Venus is the brightest object in the night sky.

• The CO2 atmosphere of Venus is very hot and thick. You would not survive a visit to the surface of the planet - you couldn't breathe the air, you would be crushed by the enormous weight of the atmosphere, and you would burn up in surface temperatures high enough to melt lead.

• The surface of Venus is mostly a rocky desert (there are many computer-generations that show lava flows around a place called Sif Mons). Like Mercury, Earth and Mars, Venus is mostly rock and metal.

• While all of the planets orbit in an ellipse (something like the shape of an egg), Venus' orbit is the closest to a perfect circle.

• Because it is often brighter than anything in the sky except the moon, Venus is the cause of many UFO reports.

EARTH

• The Diameter of earth is 7,926 miles.

• It takes 23 hours, 56 minutes for the earth to rotate completely.

• It takes 365.24 days for the earth to Orbit around the sun.

Cool facts about Earth• Earth is the third planet from

the sun. Like the other three planets of the inner solar system (Mercury, Venus, and Mars) our planet is made up mostly of rock and metal.

• One of the most important things about Earth is that there's lots of water, which is one important reason why life got started long ago. We're also lucky that Earth's atmosphere has plenty of nitrogen and oxygen, two other things that life needs.

• It may not feel like it but the ground under your feet is actually moving very, very fast. The Earth's surface is rotating about its axis at 1,532 feet per second at the equator, and the planet zips around the sun at more than 18 miles per second! So all of us are going incredibly fast -- even when we're standing still.

MARS

• The diameter of Mars is 4,217 miles.

• It takes 24 hours and 37 minutes for it to rotate 360 degrees completely.

• It takes 687 days for mars to completely orbit the sun.

• It only has 5% of the mass that the earth has.

• It has 53% of the earths diameter.

• It’s 150% further away from the sun than the moon is.

Moons of Mars

• Mars has two moons

• Phobos• Diemos: both are sons of

Ares (god of bloodlust/war) and Aphrodite (goddess of love) in Greek Mythology

• Both are believed to be captured asteroids from the nearby asteroid belt

THE “LOW DOWN” ON MARS

• The fourth planet from the sun has always made us humans do a lot wondering and hoping. While scientists haven't proven there's any life on Mars, the dusty red planet is still a fascinating place.

• The surface of Mars is more interesting than most. Like Mercury, Venus and Earth, Mars is mostly rock and metal, but it also has lots of mountains and craters.

• The dust that gives Mars the reddish color is made of something called iron oxide. Temperatures on Mars can get as cold as -207 degrees Fahrenheit and as high as 80 degrees Fahrenheit on summer days.

• Mars was probably warm and wet about 3.7 billion years ago. Mars cooled and the water froze. Some of that water still may exist in ice caps at the poles.

The Asteroid Belt

• Asteroids are small bodies that are left over from the beginning of the solar system

• They are rocky objects with round or irregular shapes up to several hundred km across, but most are much smaller.

• May be the remains of an early planet which broke up.

• The chances of an asteroid colliding with Earth are very small! But some do come close to Earth, like Hermes (closest approach of 777,000 km).

JUPITER

• Jupiter weighs over 316 times as much as the earth.

• It is also 11.12 times larger than the earth.

• The fifth planet from the sun is mostly a huge ball of gas. But at Jupiter's center is a core of rock many times the mass of Earth. The whole planet is so massive it could hold all the other planets put together!

Jupiter as a star?• It is quite interesting that the composition of

Jupiter is very much like our Sun. Jupiter is 89 percent hydrogen and eleven percent helium. The Sun: 78 percent hydrogen and 19.8 percent helium.*

• Jupiter does radiate about twice as much heat

energy as it receives from the Sun, but this heat comes from an internal reservoir left over from the planet's birth some 4.6 billion years ago. The Sun produces it's heat energy through nuclear fusion.

• The Simple Answer: not enough mass, Jupiter is too small to be a star.

Jupiter’s Moons

• Has 63 moons• Galileo discovery

Four Largest• Europa: ice? Life??• Io: active volcanism• Callisto• Ganymede

SATURN• Diameter: 74,900 miles • Time to rotate completely: 10

hours, 39 minutes • It takes 29.5 years for saturn

to orbit the sun.• The sixth planet from the sun

has a rocky core and a lot of gas on its surface. But Saturn is known for its rings. The mile-thick rings are made of tons and tons of ice that orbit the planet. Some of the ice bits are smaller than marbles, some are bigger than your computer.

• Saturn has 18 known moons, each made mostly of ice and rock.

Moons of Saturn

• Has 60 moons

• Titan has an atmosphere

• Mimas looks like the Death Star (Star Wars) from an impact crater

URANUS

•The diameter of Uranus is 31,763 miles long.•It takes the planet 17 hours and 54 minutes to turn 360 degrees.•It takes 84 years for uranus to orbit the sun.•It weighs 14.5 times as much as the earth•It is 4.1 times heavier than the earth•The seventh planet from the sun is a lot like its neighbors, with a cloudy surface, rapid winds, and small rocky core. •Uranus rotates at an extreme tilt of 98 degrees, sort of on its side. This causes one pole to point toward the sun for decades, giving the planet strange seasons. Scientists think the planet might be on its side because some other large object crashed into it a long time ago.

Moons and Rings of Uranus

• Has 27 moons, including Miranda, Puck, all of them are icy

• Complex ring system• Remember, it also

rotates on its side

The Kuiper Belt

• Region of the Solar System extending beyond the planets extending from the orbit of Neptune to the outer edge of the solar system

• Similar to the asteroid belt, but objects are frozen or icy.• comets: lumps of ice and dust, tails point away from the

sun, have very long orbital periods.

• Examples of Comets: Halley’s (76 years), Hale-Bopp (Heaven’s Gate Cult), Shoemaker-Levy (plunged into Jupiter in 1994).

• Interactive Comet Animation

Kuiper Belt

NEPTUNE• The eighth planet from the sun

(well, some of the time it's eighth, but more on that later) has a rocky core surrounded by ice, hydrogen, helium and methane.

• Like the other gas planets, Neptune has rapidly swirling winds. Its quick rotation causes fierce winds and some very strong storms. The planet has eight known moons. Like Saturn, Neptune has rings. But Neptune's rings are not as thick, and they are hard to spot.

• Neptune was discovered in 1846.

Neptune has 13 moons

• Largest moon is Triton, large compared to the rest

• Some of the others were discovered so recently they don’t have names yet!

PLUTO• The mass of pluto is .2% of the earth.• The diameter is only 18% of what the

earths is.• Pluto, which is smaller than our moon,

is a cold, dark, frozen place. We don't know very much about the tiny planet. Scientists think it is made of rock and ice. It might have a thin atmosphere of nitrogen, carbon monoxide and methane.

• Some astronomers think Pluto may have wandered into the system from a more distant place called the Kuiper Belt. In the Kuiper Belt, Pluto-like objects and comets orbit the sun. So maybe Pluto is not a planet at all, but more like a large asteroid or comet. Some scientists say Pluto may be an old moon of Neptune that escaped.

Inner Planets

Planets

w/ Sun

Sun w/ other Low Mass Stars

Sun w/ High Mass Stars