How to Find Planets With a Telescope

By Laurel Brown
Jeffrey Opp/Demand Media

Of the many objects to observe in the night sky, amateur astronomers often seek out the planets. Unlike the distant stars, which appear only as points of light in even the biggest telescopes, the planets show round disks and cloud features to an observer with a small telescope. You can observe any of the seven planets (Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune) with any size of telescope, although the higher magnification and quality telescopes will give you the best view.

Step 1

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Choose a planet to observe. Check rising and setting times for your location to see which planets are visible when you want to make your observations.

Step 2

Jeffrey Opp/Demand Media

Find the location of your planet at the time of your observations. Online sky almanacs can tell you the location (by constellation), altitude and azimuth (distance from north) of a planet at any given time.

Step 3

Jeffrey Opp/Demand Media

Locate the planet in the sky. For the visible planets (Mercury, Venus, Mars, Jupiter and Saturn), you should be able to locate the planet using a star chart and your eyes. Look for a bright object that does not appear to twinkle as much as the surrounding stars, then compare its location to your star chart. If the object does not appear on the chart, it is a planet.

Step 4

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Point your telescope at the planet. Use your telescope’s finder--the small telescope attached to the outside of the telescope tube--to aim and then adjust through the main scope. If you can change the magnification on your telescope, start at a lower magnification to find the planet, then switch to higher magnifications for the details.

Step 5

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Use the edge of the planetary disk to focus your telescope. The circular edge should be sharp and clear when the telescope is correctly focused.

Step 6

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Adjust your telescope to compensate for the sky’s apparent motion. Because the Earth rotates, the sky appears to shift position over time. When using a telescope, this motion will swiftly move the planet out of your view. Telescope drive motors can match this motion, or you can move the telescope by hand every few minutes.

About the Author

Laurel Brown has several years experience as an educator and a writer. She won the 2008 Reingold Prize for writing in the history of science. Brown has a Ph.D. and Master of Arts in the history of science and Middle Eastern studies from Columbia University, as well as a Bachelor of Arts in astrophysics from Colgate University.