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How to See Neptune

Neptune is the eighth most distant planet from the sun in our solar system. It is a 7.0 to 8.0 magnitude star that you can see on a clear night with a pair of stationary binoculars, or, to get a better look, with 4-inch or larger telescope. It was first observed in 1846 by J.G. Galle and H.L. d'Arrest, astronomers at the University of Berlin. Its existence had been predicted by mathematicians John Couch Adams and Urbain Jean Joseph Le Verrier, based on observations of Uranus, discovered by William Herschel in 1781.

Things You'll Need

Star chart
Ephemeris
Telescope

Instructions

- 1
  Look up the current position of Neptune on a star chart. The chart will help you determine its rough position with respect to the constellations and any other planets that happen to be in the same vicinity.
- 2
  Look for Neptune when it is in opposition to the sun to see it most clearly. You can determine this time by consulting an ephemeris -- a table of places and schedules to view celestial bodies -- to find out when the constellation Neptune it is nearest to is in opposition. For example, Neptune was in Capriconus in 2010, and its opposition occurred in mid-September, making this the period for optimal viewing.
- 3
  Train a pair of stationary binoculars or a telescope in the general direction of the constellation in which Neptune currently appears. Set the magnification to its lowest setting or use the viewfinder, and move the instrument until you can identify the relevant star formations in the eyepiece.
- 4
  Focus the binoculars or telescope on the bright object that is nearest to Neptune and slightly increase the magnification. Consulting the chart, move the viewing instrument toward the position of Neptune and stop when you see a faint blue disk.
- 5
  Secure the instrument and increase the magnification to its full power. With binoculars or a small telescope, Neptune won't appear much larger than a pinpoint, but you can distinguish it from the surrounding stars by its solidity and bluish hue which make it appear very different.

Astronomy