13/05/2015 Gravity and Space

13/05/2015Gravity Gravity is an attractive force that affects anything with mass: Note that this force goes both ways – the Earth is attracted to us.

13/05/2015Gravity Gravity depends on 2 things: If you double the distance the gravitational force decreases F F 1) The mass of the objects 2) The distance between them F F If you double the mass of one object you double the force

13/05/2015 Gravity and our Solar System The Sun’s gravity is what holds our solar system together. Since Jupiter is the largest planet, it has the most gravity. Pluto has the least amount of gravity of all the planets

13/05/2015 Gravity and our Solar System What do you think would happen to the planets if the sun’s gravitational pull suddenly disappeared? To get an explanation WATCH THIS!WATCH THIS! GRAVITY – it’s what holds our Solar System together!

An overview of the Solar System Now let’s learn about…

The Sun The sun is the biggest, brightest, and hottest object in the solar system. The sun is an ordinary star. The sun is made of about 70% hydrogen and 28% helium.

Mercury Mercury is solid, rocky, and is covered with craters. Mercury has almost no atmosphere. There are no moons on mercury Mercury is the smallest of our eight.

Venus Venus is the sixth largest planet. It’s slightly smaller than Earth. The surface is rocky and very hot. The atmosphere completely hides the surface and traps the heat. Venus has no moons.

Earth Earth is the fifth largest planet and the third from the sun. It is a rocky planet covered mostly by water. The Earth has one moon.

Moon

Mars Mars is the fourth planet from the sun. Mars is rocky Mars has a thin atmosphere of mostly carbon dioxide. Mars has two small moons.

Moons of Mars Phobos Deimos

Jupiter The Great Red Spot, a huge storm of swirling gas that has lasted for hundreds of years. Jupiter does not have a solid surface. The planet is a ball of liquid surrounded by gas. Jupiter has over 65 moons!

Io

Europa

Ganymede

Callisto

Saturn Saturn is the second largest planet and the sixth from the sun. Saturn is made of materials that are lighter than water. If you could fit Saturn in a lake, it would float! Saturn has 62 moons.

Rings of Saturn Saturn’s rings are not solid; they are composed of small particles of ice and rock.

Uranus Uranus is the third largest planet and the seventh from the sun. Uranus is one of the giant gas planets. Uranus is blue-green because of the methane in its atmosphere.

Neptune Neptune is the fourth largest planet and the eight from the sun. Like Uranus, the methane gas gives Neptune its color. Neptune has 13 known moons

How Did We Learn All This? Now, let’s look at a few of history’s greatest contributions to space exploration and learn about the different crafts used.

Galileo Galilei He was a famous mathematician and astronomer who made great advances in the telescope – the first step in exploring space.

Robert Goddard Robert H. Goddard is know as the American father of modern rocketry He built and tested the world's first liquid-fuel rocket in Over the course of his career, Goddard not only developed the calculations for rocket flight and also made advances in rocket design and construction.

What is a rocket? Rockets are space craft with chemical propellants used to escape the earths gravity.

Sputnik 1 The first manmade satellite to orbit the earth – Soviet Union.

Explorer 1 The first U.S. satellite to orbit the Earth.

What is a satellite? An object that orbits another object. They can be natural, like a moon orbiting a planet, or artificial, like Explorer 1.

13/05/2015 Natural Satellites Mercury Mars Jupiter Saturn Neptune Uranus Pluto Venus Earth These planets are all satellites of the sun

13/05/2015 Artificial Satellites 1) Observation (e.g. Hubble Space Telescope) – these are in orbit high above the Earth and can observe the universe without interference 2) Communications – radio, phone, navigation 3) Monitoring – weather and spying Artificial satellites have been around for 50 years and have 3 main uses:

Voyager 1 and 2 These were probes discovered many things including the rings and moons of the far away gas giant. It is the farthest man mad object in space. 13/05/2015

What is a probe? What is a probe? A space probe is a robotic spacecraft that leaves Earth orbit and explores space. 13/05/2015

NASA Strands for National Aeronautics and Space Administration. It is our governmental agency devoted to exploring space.

Apollo Missions These missions were to land a man on the moon and return him safely. 13/05/2015 "That's one small step for a man. One giant leap for mankind." - Neil Armstrong

The Space Shuttle This program created the first reusable space craft that could carry people and cargo to and from space.