Forms of electromagnetic radiation differ in their frequencies.
Frequency : # of wave crests that pass a given point per unit of time.
The shorter the wavelength, the higher the frequency.
Speed of Light
ALL electromagnetic waves travel at this speed in a vacuum (where there is no matter)
First to Use a Telescope to Study the Sky
Galileo in 1600’s
Use light to produce magnified images.
Refracting telescope: convex lenses
Reflecting telescope: concave mirror.
Where optical telescopes are located.
Edwin P. Hubble Discovered: Universe is Expanding Hubble Space Telescope named after him.
Hubble Space Telescope
Located outside Earth’s atmosphere
Studies radio waves that travel through space.
Useful 24 hours
Early Space Missions
Allowed astronomers to study space in ways not possible using telescopes.
Made possible by rockets.
Any object that
in an orbit
In 1957 the former
launched first artificial
satellite: Sputnik I.
Thousands of artificial satellites orbit Earth
Used for: communication and weather forecasting.
Do not orbit Earth
Travel through space.
Space Probes: Pioneer 10
1 st manmade object
to travel through
failed in 2003
Space Probes: Voyager I & II
Launched by U.S. in 1977
Expected to collect data until 2020
Saturn Taken by Voyager II 1981
Images from Voyager Space Probes Voyager 2: 1981 Rings of Saturn
Images from Voyager Space Probes - Voyager 2 - 1989 - Neptune
By 1990, Voyager 1 was farther from the Sun than Pluto, and approximately 4 billion miles from the Earth. Thus, NASA gave Voyager 1 one last assignment and had the craft take the first ever pictures of the planets from “outside” the solar system. This is a compilation of those shots.
Images from Voyager Space Probes
Space Probe: Galileo
Launched in 1989
Reached Jupiter in 1995
Released smaller probe to approach Jupiter.
Studied Europa and Io (Jupiter’s moons)
Yuri Gagarin: 1 st man in space (Soviet)
Project Mercury: began U.S. mission to put a man in space.
1961: Alan Shepard: 1 st U.S. man in space
1962: John Glenn: 1 st U.S. citizen to orbit Earth
Men in Space Yuri Gagarin 1 st man to orbit Earth
Men in Space Alan Shepherd John Glenn
Teams of 2 astronauts in the same Gemini spacecraft orbited Earth. One Gemini team met and connected with another spacecraft in orbit.
Robotic Probes Sent to the Moon
Surveyor: landed on moon in 1966
Lunar Orbiter: took pictures of moon’s surface
1969: Apollo II landed on the Moon
Neil Armstrong: 1 st person to step on Moon
1973: U.S. launched Skylab
Fell out of orbit in 1979
Dr. Valery Polyakov spent 438 days in space studying the long-term effects of weightlessness.
International Space Station
Effort of 16 nations
Should be completed by 2006
Missions to Mars
Mars Global Surveyor: orbited Mars and took pictures.
Pathfinder: descended to surface of Mars
Mars Odyssey: mapping surface of Mars
Spirit and Opportunity: rovers launched in 2003: goal to analyze surface of mars