A SOLAR SYSTEM is made up of a star and all the planets and other objects that revolve around that star. Our solar system consists of the Sun and the 8 planets that revolve around it. It is a small part of a much larger system called the Milky Way Galaxy .
A PLANET is a body that revolves around a star. We have 8 planets in our solar system that revolve around the sun.
Inner Planets Outer Planets Asteroid Belt Located between Mars and Jupiter, The asteroid belt separates the Inner Planets from the Outer Planets. Planets closest to the Sun are smaller and mostly solid (formed from heavy, rocky materials). Planets farthest from the Sun are larger and formed mainly of gases.
Has 8 moons – one moon is Titan, which has many geysers (springs that shoot up super-heated vapors (gases) constantly)
Seventh planet from the sun
A gas giant that looks blue-green because of the methane gas in the atmosphere.
Faint gray rings around it
At least 15 moons
Rotates differently than the other planets – it spins as though it is lying on its side (scientists thought another planet’s gravity might be pulling it to spin like that. They looked for another planet that might be doing this and found Neptune)
Stars are classified by their color, temperatures, sizes, and brightness
Have life cycles
1-Begins as a cloud of gas and dust called a Nebula
2-Cloud moves around and picks up more and more gas and
dust – like a snowball rolling down a hill and getting bigger
and bigger and gets really big and hot
3-eventually runs out of gas and burns out – the burnt out star
will blow up, shrink or go cold. This whole cycle can take billions of years to happen
*Blue Stars- bigger than yellow stars, called blue giants they are very bright and very hot. When they die they larger and larger and then explode into a … *Supernova- so bright that they can be seen from very far away Super giant stars – largest that can be seen with bare eyes is called Betelgeuse. It is 700 times bigger than the Sun.
Galaxies are huge collections of stars, dust and gas. They usually contain several million to over a trillion stars and can range in size from a few thousand to several hundred thousand light-years across. There are hundreds of billions of galaxies in the universe. Galaxies come in many different sizes, shapes and brightness and, like stars, are found alone, in pairs, or in larger groups called clusters . Galaxies are divided into three basic types: spirals , ellipticals and irregulars .
CAST OF GALAXIES… THE 3 MAIN TYPES OF GALAXIES. Elliptical galaxies are shaped like ellipses (stretched circles). They are divided into eight types: E0-E7 depending on how elliptical they are. E0 ellipticals are nearly circular, while E7s are very stretched out. Elliptical galaxies are made up of mostly old stars, and do not have much gas and dust. There is very little new star formation in these galaxies. Elliptical galaxies also come in many sizes. The largest galaxies we see are elliptical, but, elliptical galaxies can also be small. About 60% of all galaxies are elliptical. Irregular galaxies have no particular shape. They are among the smallest galaxies and are full of gas and dust. Having a lot of gas and dust means that these galaxies have a lot of star formation going on within them. This can make them very bright. The Large and Small Magellan Clouds are examples of irregular galaxies. They are two small galaxies which orbit around our own Milky Way galaxy. About 20% of all galaxies are irregulars. Spiral galaxies get their name from the shape of their disks. In a spiral galaxy, the stars, gas and dust are gathered in spiral arms that spread outward from the galaxy's center. Spiral galaxys are divided into three main types depending on how tightly wound their spiral arms are: Sa, Sb and Sc. Spiral galaxies have a lot of gas, dust and newly forming stars. Since they have a lot of hot, young stars, they are often among the brightest galaxies in the universe. About 20% of all galaxies are spirals. We live in a spiral galaxy called the Milky Way.
THE MILKY WAY… Our home in the stars… It takes the sun 200 million years to make one rotation around the center! The Milky Way is the galaxy in which we live. It is a spiral shaped galaxy that contains about 200 billion stars, including our Sun. It is about 100,000 light-years across and about 10,000 light-years thick. If you are at a place which has a very dark night sky, you can sometimes see the Milky Way as a thick band of stars in the sky. We live near the edge of the Milky Way.
A constellation is a group of stars visible within a particular region of the night sky. Some were named after animals and some mythological characters. Some constellations were named after some scientific instruments. Constellations can be viewed after sunset and before sunrise. Also, as the earth turns you can see different constellations.
Jill and her father observed the Big and Little Dippers at the same time each evening for four weeks, using a tree in her yard as a reference point. They made sketches of their observations and noticed that the constellations changed their positions relative to the tree in her yard over this time period. What caused this apparent change of position?
A. The Earth was revolving around the sun.
B. The constellations were revolving through phases of the night sky.
C. The Earth was rotating on its axis.
D. The constellations were rotating around a point in the night sky.