All Planet Sizes

This illustration from the Lunar and Planetary Laboratory shows the approximate sizes of the planets relative to each other. Note that the planets are not shown at appropriate distances from the Sun.

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.

Caves: Extreme Conditions for Life

This video segment adapted from NOVA raises the provocative idea that if life can exist in the most extreme environments on Earth — such as in dark, toxic caves — then perhaps living things can also survive in harsh environments on other planets.

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Cosmic Origin Spectrograph

This video from NASA features the Cosmic Origin Spectrograph (COS), which allows scientists to use spectrographic analysis to assess the composition of intergalactic material.

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Eclipse of the Century

This video segment adapted from NOVA features spectacular footage from the 1991 solar eclipse that fortuitously occurred directly over several major astronomical observatories in Hawaiʻi.

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Evolution of the Universe

In this video from NASA, learn how the James Webb Space Telescope is helping scientists understand when and how early stars formed, what early galaxies looked like, and how the early universe shaped its underlying structure.

Exoplanets

This video segment from IdahoPTV's D4K shows the tools scientists use to search for exoplanets and describes possible characteristics a planet might have to support life.

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Extreme Temperatures on the Moon

In this video segment adapted from Interactive NOVA, astronaut John Young experiences extreme temperatures on the Moon that are a result of the Moon's low gravity and lack of atmosphere.

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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 on the Moon

Watch Apollo 15 astronaut David Scott perform Galileo's falling objects experiment on the Moon in this video segment from NASA.

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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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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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Ingredients for Life: Carbon

This video segment adapted from NOVA illustrates why carbon is at the center of life on Earth. It also asks whether carbon-based life might exist on other planets.

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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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Meteor Showers

This video segment adapted from NASA uses animation to illustrate the properties of meteor showers and comets. Included is are visualizations of a comet's tail and of Earth passing through a debris stream left behind by meteoroids.

Monster Black Hole in Galaxy M84

This animation by Thomas Goertel of the Space Telescope Science Institute is an artist's conception of a spiral galaxy harboring a super-massive black hole. Observe how the material rotates faster the closer it is to the nucleus.

A New Theory of Lightning

In this video segment adapted from NOVA scienceNOW, follow scientists as they test a new theory suggesting that lightning here on Earth is triggered by cosmic rays from far-away dying stars.

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The Origin of the Elements

This video segment adapted from NOVA explains the origin of the elements and how scientists use unique element profiles to identify supernova types.

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The Origin of the Moon

This video segment adapted from NOVA follows the Apollo 15 astronauts as they collect samples of ancient rock from the Moon's crust, whose discovery helps lead to a radical new theory about the Moon's origin.

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