Astronomical Images in Different Wavelengths

Visible light is just one portion of the electromagnetic spectrum that a telescope may detect. This collection of images produced for Teachers' Domain features radio wave, infrared, visible light, and X-ray images of distant stars and galaxies as well as images of the telescopes designed to detect the various wavelengths of radiation.

The Beginnings of the Telescope

This animated essay from the NOVA Web site examines the design of Galileo's refracting telescope and Sir Isaac Newton's reflecting telescope.

Birth of a Supernova, Type Ia

In this interactive activity from NOVA Online, learn about a type of exploding star — a Type Ia supernova — that is so bright that astronomers can measure the distance to the galaxy in which it resides, and even learn which elements make up the star.

Birth of a Supernova, Type II

In this interactive activity from NOVA Online, learn about a type of exploding star — a Type II supernova — that is so large it has a mass 10 times greater than the mass of our Sun.

Evidence for the Big Bang Theory

This video segment adapted from NOVA tells the story of two scientists who inadvertently discovered microwave radiation that is now believed to be heat left over from the Big Bang.

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Galileo: Discovering Jupiter's Moons

This video segment adapted from NOVA shows how Galileo, using his newly developed refracting telescope, observed four of Jupiter's moons, the first astronomical bodies to be discovered since ancient times.

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Galileo's Big Mistake

Scientists don't always get it right. This video segment adapted from NOVA looks at Galileo's failed theory for the motion of the tides.

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Galileo: Sun-Centered System

In the early 1600s, most people believed that the Sun revolved around a stationary Earth. This video segment adapted from NOVA tells how Galileo proved that the Sun, not Earth, is at the center of our universe.

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Galileo: Sunspots

This video segment adapted from NOVA shows how Galileo used his telescope to carefully observe and study sunspots.

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How Big Is Our Universe?

This interactive resource from Harvard Smithsonian Center for Astrophysics uses images and activities to understand the scope and scale of our universe. Featured are technologies used by generations of explorers.

Hubble Telescope: Looking Deep

This video segment adapted from the Space Telescope Science Institute shows what the Hubble telescope found when it stared at a single, nearly empty spot in the sky for 10 days in 1995. The unexpected result was a picture of a multitude of galaxies stretching into the distance.

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Infrared Gallery

How would your world look if you saw heat instead of light? In this interactive resource produced for Teachers' Domain, see what familiar objects look like through an infrared camera and watch infrared videos of geysers, mudpots, and hot springs.

Infrared Search for Origins

This interactive resource from NASA illustrates how infrared technology has advanced space exploration and can offer insight into questions about star formation, planetary systems, brown dwarfs, and the origins of the universe.

James Webb vs Hubble

Compare two space telescopes—the Hubble Space Telescope and its planned successor, the James Webb Space Telescope —in this interactive activity from NASA.

Jupiter: Earth's Shield

Jupiter's immense gravity protects Earth from asteroids. In this video segment adapted from NOVA, scientists searching for signs of life in the universe identify solar systems with Jupiter-like planets that may be shielding smaller nearby Earth-like planets from comets and asteroids.

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Robotic Exploration of Space Timeline

This interactive timeline from NASA journeys through the last century, detailing key discoveries, experiments, missions, and other events that brought robotic space exploration from science fiction to reality.

The Search for Another Earth

This NASA video provides an overview of technology under development to explore the planets and stars outside our solar system. These will be the most sensitive instruments built to date.

Solar Magnetism

This video segment adapted from NOVA describes how the Sun's magnetism can have an effect here on Earth, from dramatic auroras to a mini-Ice Age in the 1600s.

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Spectrometry Explained

Find out how light can be used to identify chemical compounds in this interactive activity adapted from NASA.

Spin a Spiral Galaxy

This interactive activity from NOVA Online lets you spin a spiral galaxy, including our own Milky Way. It demonstrates that what you can learn from visible light observations of a galaxy is largely determined by the angle from which you are observing it.