refracting telescope Telescopes that use convex lenses to collect and focus light.
space telescope Telescopes in orbit above Earth’s atmosphere.
spectrometer A tool that uses a prism to break light into its component colors.
ultraviolet Electromagnetic radiation having wavelengths shorter than the violet.
wavelength Horizontal distance measured from wave crest to wave crest, or wave trough
to wave trough.
visible light Theportionoflightintheelectromagneticspectrumthatisvisibletohumans.
X rays A band of electromagnetic radiation between gamma and ultraviolet.
Points to Consider
- Radio waves are used for communicating with spacecraft. A round-trip communication
from Earth to Mars takes anywhere from 6 to 42 minutes. What challenges might this
present for sending unmanned spacecraft and probes to Mars? - The Hubble Space Telescope is a very important source of data for astronomers. The
fascinating and beautiful images from the Hubble also help to maintain public support
for science. However, the Hubble is growing old. Missions to service and maintain the
telescope are extremely expensive and put the lives of astronauts at risk. - Do you think there should be another servicing mission to the Hubble?
23.2 Early Space Exploration
Lesson Objectives
- Explain how a rocket works.
- Describe different types of satellites.
- Outline major events in early space exploration, including the Space Race.
Introduction
Humans have long dreamed of traveling into space. Greek mythology tells of Daedelus and
Icarus, a father and son who took flight using wings made of feathers and wax. Daedelus