How Do I Locate Venus and Saturn in the Night Sky by Longitude and Latitude?
- 1). Identify your approximate latitude and longitude. You can get this information online, by visiting sites like Find Latitude and Longitude (see Resources). For the purposes of stargazing, your latitude is more important than your longitude. Observers who share the same latitude see the stars and planets in the same positions at local time, regardless of differences in longitude.
- 2). Search astronomy sites like Your Sky and APL Starmaps to find sky maps that correspond to your coordinates (see Resources). You do not need to find charts that match your latitude and longitude exactly; any sky map that matches your latitude within a few degrees should be sufficient for locating the planets. You can also create a free account on Heavens-Above to generate sky maps and planetary viewing charts specifically calibrated to your coordinates.
- 3). Check your sky maps to determine whether Venus and Saturn are currently visible from your location, or check the rise and set times for each planet online. Heavens-Above and Old Farmer's Almanac Online offer rise and set times for each planet, based on your latitude and longitude (see Resources).
Remember that at certain times of year, the planets disappear behind the sun, or appear in the sky only by day, when the light of the sun makes them invisible. Be sure to look for the planets when they are actually visible in the night sky. Also, note that the two planets will not always appear at the same time. - 4). Go outside on a clear night and use your sky map to locate Venus and Saturn in relation to bright stars and other celestial landmarks. You will always find planets along the ecliptic, which runs in an arc from the southeast to the southwest.
Face south, and hold your chart overhead (facing downward), so that north is behind you and east is to your left. (Note that the directions differ from those on a terrestrial map.)
If you use a flashlight or headlamp, tape a piece of red cellophane or plastic wrap over the light before you go out. This will allow you to read the charts, while reducing glare and keeping your night vision intact. - 5). Look for Venus close to the horizon, just after sunset or before sunrise, depending on the time of year. Because Venus has such a small orbit, the planet always appears close to the sun, and never directly overhead. Also known as the "evening star" or the "morning star," Venus is the brightest of the planets and is easy to spot. Apart from the moon, Venus is the brightest object in the night sky.
- 6). Look for Saturn higher in the sky. Saturn is the third-brightest planet, after Venus and Jupiter, and appears equal in magnitude to the brightest fixed stars. Saturn shines with an orange-yellow hue.
The planet's rings are also visible in good conditions if viewed through a small telescope, or binoculars of at least 20x magnification. Mount your instrument on a tripod, or brace it against a flat surface, for the clearest viewing.