The Universe Image taken from www.bbc.co.uk

Galaxies and the Universe - Notes

Astronomy The branch of science that deals with objects in the universe and space

The Universe The universe is composed of ALL matter and energy in space The universe is made of 3 major components: galaxies solar systems planets Can you think of something in the universe that cannot be seen, but its effects on other things can be detected?

There have been many scientists who have studied the universe..

Gallileo Used early telescopes to describe the surface of the moon Found that Jupiter and Venus had moons on them Discovered that the Earth was not the center of the solar system Is known as the Father of Modern Science http://www.biography.com/people/galileo-9305220#death-and-legacy

Sir Isaac Newton Discovered laws of gravity Proved that gravity is a force that pulls smaller objects toward larger ones From www.biography.com

Telescope Types: a device that gathers electromagnetic radiation Visible, infrared, ultraviolet – pick up visible, infrared, and ultraviolet waves Reflecting - use mirrors that reflect the image being viewed Refracting – using lenses, gathers light and focuses it near the opposite end of the tube; works like a magnifying glass Radio - pick up radio waves emitted from space; not effected by variables like weather or clouds Internet Telescope

Edwin Hubble Scientist that determined that the universe is made of many galaxies He observed that galaxies were moving away from each other Hubble Law – the farther away a galaxy is, the faster it is moving away from us Image taken from: http://apod.nasa.gov/apod/ap960217.html

Hubble Space Telescope a reflecting telescope that was placed into orbit in 1990 sends images and measurements back to Earth electronically Image taken from: http://hubblesite.org/gallery/ What is one of the main benefits of having the Hubble Space Telescope in orbit, as opposed to it being here on Earth?

Hubble Space Telescope Telescope used to study the far reaches of the universe The telescope was named after Edwin Hubble It has been in orbit since 1990 Can take pictures of the universe objects further away than any other telescope The HST was the first to take pictures of other galaxies

The Universe is Made of Many Galaxies

A Galaxy is…. A large collection of stars, gas and dust Contains millions to hundreds of billions of stars Star - a large hot ball of gas which generates energy in its core by nuclear reactions Held together by the gravitational attraction of all its member stars on one another Sometimes contain very bright centers called quasars Three major types: Spiral Elliptical Irregular Q: What is the name of the galaxy we reside in?

3 Types of Galaxies Spiral have arms of stars, gas , and dust that curve away from the center of the galaxy in a spiral pattern Ex. – Milky Way Elliptical shaped like spheres or eggs; have almost no dust or gas between stars; contain old stars Irregular faint galaxies without a definite shape; smaller than the other types of galaxies; contain fewer stars Images taken from: http://school.discoveryeducation.com/schooladventures/universe/galaxytour/toknow.html

A Galaxy is made of several components…. What type of Galaxy is this? How do you know?

Solar System Includes the sun and all objects orbiting around it Including the eight major planets, their satellites (moons), and all the smaller pieces such as asteroids and comets It was formed around 4.6 billion years ago Why are the objects in this photo shown in different places? Image taken from: http://www.nasa.gov

Planet Is a major object which orbits around a star There are 8 in the Milky Way solar system Can be made of gas, rock or plasma

to see all constellations A Constellation Is a group of stars that form a pattern in the sky Ancient cultures used constellations to tell stories Stars of a constellation are often far apart from each other, but they appear grouped together when viewed from Earth Why is it not possible to see all constellations at once?

Asteroids Small rocky objects that orbit close to the Sun Most are found between Mars and Jupiter in the “Asteroid Belt” Scientists think that asteroids may be leftover material from the formation of the solar system Image taken from: http://www.windows.ucar.edu/tour/link=/our_solar_system/asteroids.html

Meteoroid, Meteor, Meteorite Meteoroid (asteroid) Meteoroid – solid debris from space (asteroids) that are moving towards Earth Meteor When the small particle enters the Earth’s atmosphere at high speed It is also called “shooting stars” or “falling stars” Meteorite – when the small particle reaches the Earth’s surface Freehold Meteorite - MSNBC Freehold Meteorite - USA-Today Meteor Meteorite The Earth animation is not rotating in the correct direction; it should be rotating from west to east What causes a meteor shower to occur?

Comet A small object made of ice and dust that orbits the Sun Contains a head (coma) followed by a tail(s) of gas and dust The tail always points away from the sun and Image from http://images.wisegeek.com/parts-of-a-comet.jpg

Satellite An object that orbits a more massive object (i.e. – moons) Probes that are launched into orbit around the Earth are called “artificial satellites” The Earth animation is not rotating in the correct direction; it should be rotating from west to east