Astonomy and The Solar System Grade 5

Astronomy Why is it necessary for people to study astronomy? Could life exist on another planet? Is all life on Earth affected by the Sun and Moon? Did stars enhance civilization?

Astronomy The study of objects in space. Text - Pgs

Best of The Solar System Background Information: Mercury, Venus, Mars, Jupiter and Saturn are the five planets visible to the human eye. Although the planets look like stars, they do not move like stars. Ancient stargazers noticed that five stars changed position with respect to the other stars and each other. The Greeks called these stars planets, which means "wanderers". For hundreds of years researchers tried to explain the motion of these "wandering stars". Students can learn more about early astronomers and their work by doing library research on Aristarchus of Samos, Ptolemy, Copernicus, Tycho Brahe and Johannes Kepler.

Astronomers began using the telescope to study the sky in the 1600's. For over 300 years the telescope was the most important tool for astronomers. Galileo made some of the earliest discoveries with the telescope. However, Galileo did not invent the telescope; he was not even the first to use a telescope to study the sky. Galileo is known for his careful observations and the detailed records in his journal. Galileo sketched the features of the moon and even measured some of the mountains. He discovered the four large satellites of Jupiter. Galileo observed that Venus went through phases like the phases of the moon. Sunspots were discovered independently by Galileo, Fabricius and Scheiner. Around 1655 Christiaan Huygens discovered the rings of Saturn and Saturn's largest moon. In 1781 William Herschel discovered Uranus. Later he discovered two new satellites of Saturn and two satellites of Uranus. Leverrier and Adams calculated the approximate location of Neptune. Using these calculations, Galle and d'Arrest where able to confirm Neptune's existence in 1846.

Astronomer Uses a telescope to study distant objects A telescope is used to study objects in the Solar System and beyond.

Sun Sun - average-sized star that has a diameter of 1.4 million kilometers. It is 150,000,000 kilometers from Earth.

Composition In the core of the sun, hydrogen particles fuse to produce helium. Every time this happens, the sun releases energy. Energy from the sun is released as heat and light. It travels in waves.

Structure of the Sun core - inner part with a temperature of 15,000,000oC prominence - bright red loops or streams of gas in the corona

Solar Flares brief bursts of energy from the sun's photosphere. When energy from solar flares reach Earth, it causes beautiful light displays near the poles called auroras.

Aurora

Sunspots dark area on the photosphere; cooler than the rest of the sun; Cycle of approximately eleven years; may interrupt radio communications

Sunspot

Solar Eclipse Occurs when the moon passes between the Sun and Earth and blocks the Sun’s light.

Time Zones Earth’s 24 hour cycle of daylight and darkness, due to its rotation causes sunrise and sunset to occur at different times in different places. Ex. 5 PM in Pennsylvania is 2 PM in California.

EARTH ROTATES on its axis,- Turns around AXIS - an imaginary line running North/South. PERIOD OF ROTATION - It takes 23 hours 56 minutes. (ONE DAY!)

ORBIT - The path earth takes around the sun. REVOLUTION - The movement of a planet along its orbit.

It takes Earth 365 1/4 days to revolve around the Sun. PERIOD OF REVOLUTION - one year! Harcourt - Pg

Seasons Earth’s tilt on its axis causes the changing seasons. During the summer, the hemisphere is tilted toward the sun, receiving more direct sunlight.

Summer Solstice The day when the amount of daylight is the greatest. Northern Hemisphere - June 20 or 21

Winter Solstice The day when there is the least amount of daylight Northern Hemisphere: December 21 or 22

Composition of Earth Landforms Areas of soil-covered rock shaped by Weathering, erosion, and deposition Water 70% of surface is covered with salt water

Northern Hemisphere - Equinox The days when daylight and darkness are about equal. Autumn Equinox - Sept. 22 or 23 Spring Equinox - March 20 or 21

Composition - in the core of the sun, hydrogen particles fuse to produce helium. Every time this happens, the sun releases energy. 2. Energy from the sun is released as heat and light. It travels in waves.

Space Probe Another method of studying space is to use a space probe. A space probe is a spacecraft without humans aboard that gathers data about objects in space.. Voyager I and II have sent back pictures of Jupiter, Saturn, Uranus, and Neptune

Hubble Space Telescope Launched in 1990 Produces images five times as sharp as those from any telescope on Earth

Solar System The Solar System is made up of a star and planets and other objects that revolve around that star

The sun is the center of the solar system. It is a star.

Planets A planet is a large body of rock or gas that orbits the sun. The solar system has eight planets, including Earth. (Today, Pluto is considered a dwarf planet.)

Inner Planets 1. Mercury 2. Venus 3. Earth 4. Mars They are the four planets closest to the sun. Pg

Inner Planets They all have rocky surfaces, and they are warmer than the outer planets.

Earth is different from the other inner planets. It has a watery surface. It is the only planet with a lot of oxygen in its atmosphere. Earth has plant life and animal life.

Outer Planets 1. Jupiter 2. Saturn 3. Uranus 4. Neptune 5. Pluto - (dwarf planet)

Outer Planets are made mostly of frozen gases. Their surfaces are colder than the inner planets because they are farther away from the sun. Most outer planets have many moons.

Pluto is different from other outer planets. It is the smallest planet in the solar system. It is called a dwarf planet.