image credit: NASA; image source; larger image

NASA-Apollo Missions

This historic photograph shows Earth, the moon, and NASA's Apollo 11 lunar module. The photo was taken from the command service module, which remained in orbit around the moon while the lunar module landed and then spent 21 hours on the moon's surface. During the Apollo 11 mission, astronauts set foot on the moon for the first time.

For more Apollo 11 information and photos, visit this NASA Apollo 11 page and also this Lunar Planetary Institute site.

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How Things Fly: Kepler's Laws of Orbital Motion

Visit How Things Fly: Kepler's Laws of Orbital Motion to visualize the predictions of Kepler's laws.

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image credit: NASA/JPL-Caltech/Space Science Institute; image source; larger image

NASA Releases Images of Earth by Distant Spacecraft

For an interesting perspective on the solar system, take a look at this image of Saturn, its rings, and Earth, which is the blue dot near the bottom right (indicated by the arrow). NASA claims that the moon can be seen sticking out on the right of this tiny blue dot slightly to the right of center (compare with the image in this earlier Physics to Go feature). To learn more, visit this NASA news item.

The particles that make up Saturn's rings are in orbit around the planet, in the same way that the planets orbit the sun. Even particles as small as dust move in this kind of orbit. See this additional NASA news item for evidence of dust orbiting the sun in Earth's "tail."

Johannes Kepler: The Laws of Planetary Motion

To learn more about Kepler's laws, and learn a little historical background too, visit Johannes Kepler: The Laws of Planetary Motion.