CHAPTER 30 Basics of Astronomy

Basic Vocabulary Calendars…a means of keeping track of all the days in a year Mayans (2000 BC) and Chinese (1300 BC) were the first to calculate the correct length of a year (365.25 days)

The Lunar Cycle The phases occur because of the different positions of the Earth, Moon and Sun Orbit is the path the moon moves around the Earth…it orbits in a counterclockwise direction (same direction that the Earth orbits the sun. New moon: moon is between Earth and Sun (cycle takes 29.5 days to complete) Full moon: moon is on the opposite side of Earth and Sun

Moon Phases

Days / Months / Years Axis: imaginary line that connects the North and South poles Rotation is Earth spinning on its axis…one rotation is one day Revolution is the movement of one object around another…one year is the time it takes for one revolution around the sun

The Seasons Are caused because of how the Earth orbits around the sun. The axis that the Earth rotates on stays the same (23.5 degrees). Here is a diagram that will explain the seasons

The Seasons

Lunar and Solar Eclipses Solar eclipse occurs when the moon’s shadow falls on the Earth Lunar eclipse occurs when the Earth’s shadow falls on the moon. A lunar eclipse can be either a total eclipse or a partial eclipse

Lunar and Solar Eclipses

Objects in space Universe is all matter and energy Star is a sphere of gas that has gone through fusion (fuse together)…example would be the North Star or the Sun Planet is a large, spherical piece of matter that revolves around a star Galaxy is a collection of gases, dust, and billions of stars…example is the Milky Way Satellite is an object that orbits around another object…example the Moon

Telescopes Galileo (1600’s) was the first to use a telescope Telescope is a device that makes objects far away appear closer Refracting telescopes use lenses Reflecting telescopes use mirrors

Common Telescopes

Space Shuttles Shuttle is a manned spacecraft that can be reused Parts of a shuttle: Solid Rocket Boosters (SRB’s) Fuel Tank (store liquid hydrogen and oxygen) Orbiter (the shuttle)

Space Shuttle Parts

Flight Path of a Shuttle