The Sun's Family

[Music] [Applause] [Music] when you look up at the sky on a clear night what do you see there's the moon and the stars the Moon looks like the biggest thing in the sky doesn't it those tiny looking stars are larger than the moon but they are much farther away millions and trillions of miles away you know how large an airplane looks when you see it on the ground and how small it seems when it's far off in the air [Music] if we were able to travel close to a star it would look like a huge ball of brilliantly glowing gases but since stars are so far away from the earth we on Earth get very little of their distant light and heat that is except for one star which is so much closer to us than the others this star is our sun you may never have thought of the Sun as being a star but that's just what it is in the daytime when our side of the earth faces the sun its brilliant light outshines the other stars which are so much farther away that they are invisible at night our side of the earth is turned away from the sun we can no longer see the Sun's light and the other stars then become visible All of the Stars including our sun give off their own light but a few of those bright spots in the sky are not stars and they shine only because they reflect the Sun's light they are called planets the planets are always moving about the star that we call the sun this is a model of the sun and the planets the model planets are little balls of various sizes that move around the sun which is represented by a white ping-pong ball actually they sun is many times larger than any of the planets our Earth is a planet too and travels above the sun just as the others do the planets that move about the sun belong to the sun's family now many stars have names and the name given to our son is Saul that's why we also speak of the sun's family as being Saul system or the solar system not only do we have names for the stars but we've given names to the planets as well the planet closest to the Sun is Mercury the next is Venus the third planet from the Sun is our own Planet the Earth Mars is the fourth planet now these first four planets are pretty much the same in size but the next planet is much larger in fact it is the largest of all the planets this giant planet is called Jupiter then after Jupiter is the planet Saturn which is just a little smaller the seventh planet Uranus is about half as large as Saturn the eighth planet is called Neptune and far far out in space is Tiny Pluto the ninth planet these are the nine planets that have been discovered so far they are always moving about the sun each planet travels in its own separate path we call this path the planet's orbit do you notice that the planets that are closer to the Sun move about it much more quickly than those farther away it actually takes Mercury the planet closest to the Sun only 88 days to go completely around it that's about as long as your summer vacation our earth goes about the sun once each year and the planet farthest away from the Sun Pluto naturally has the greatest distance to travel it makes the trip around the Sun in about 248 years in this model the planets look rather close to the Sun but actually they are millions and millions of miles away from the Sun if a rocket were to set out from the Earth traveling through space at the rate of one thousand miles per hour it would take more than 10 years to reach the Sun if the same right miles per hour it would take almost 450 years to reach the Sun how do we know all these things about the solar system we get all our knowledge about the stars and planets and all the other things in the sky from scientists who work in special buildings like this one the scientists are called astronomers and they look through powerful telescopes which make the bodies in the sky seem to be much closer when we look through one of these telescopes at the planet Mars we can see what seems to be a white cat near the top can this be an ice cap such as our Earth has at its North Pole are there any living things on Mars some astronomers say perhaps but no one really knows the answers to these questions Jupiter as seen through the telescope is covered with so many clouds that it is difficult to see through them perhaps you noticed in the model of the solar system that Saturn had a ring around it when we look at Saturn through the telescope we can see that it actually has several Rings the astronomer says that the Rings are made of countless particles of dust and stone that move around the planet you have learned a few important facts about our sun and its nine planets and while they are the main parts of the sun's family there are other heavenly bodies that will perhaps you will learn something about meteors and comets and the part they play in the solar system is the moon a part of the sun's family are there any other moons perhaps you can find the answers foreign