Back to Articles Home

How to Find the Planets in the night sky


Since ancient times, before the advent of the telescope, astronomers and others were able to pick out moving points of light that looked different from stars. The Greeks named them planetes asteres, which means wandering stars. These visible planets are easy to locate and identify if you simply know where to look and what to look for.

Steps

  1. Learn the orbits of the visible planets. This seems easy enough, but it frequently causes trouble. The orbits of Mercury and Venus lie between the orbit of the Earth and the Sun. For this reason, they are always found in the morning or evening skies, with Mercury always closest to the horizon. Mars, Jupiter and Saturn lie outside of our orbit, so they are typically found throughout the night.
  2. Learn their appearance. Each of the planets has a shade and appearance that identified them; Mercury is the faintest and simply looked white, while Venus can outshine them all. Mars has a ruddy, reddish hue, while Jupiter is second to Venus in brilliance most of the time, and looks yellowish-white. Saturn, the most distant of the original planets, shines a pale yellow. The planets do not twinkle as well, since they are much closer than the distant stars (which appear essentially as pinpoints of light).
  3. Learn where to look. Now that you know where they orbit and what they look like, we need to know where to look. The planets lie on or near what is known as the plane of the ecliptic, the path the Sun follows through the sky. Knowing this path isn't enough, though, since the planets are moving targets. Astronomers use an ephemeris to locate the planets, but for the amateur it is probably easier to use software an online astronomy service to know where to look.

Tips

  • The planets are almost always brighter than stars, making them easier to find.
  • Uranus, while not one of the classic planets, is also just visible to the naked eye under dark skies.
  • Mercury is the most daunting planet to locate due to its proximity to the Sun. With a little practice, it can be located.
  • Three of the planets, Mercury, Venus and Mars, have noticeable movement. Study them over a period of nights and you can see their movement, with Mercury being by far the fastest.
  • It is not necessary to use a telescope to see the classic planets, just a good clear sky.

Related wikiHows

Article provided by wikiHow, a wiki how-to manual. Please edit this article and find author credits at the original wikiHow article on How to Find the Planets. All content on wikiHow can be shared under a Creative Commons license.