Look up tonight
Simple, friendly notes for anyone who has ever stepped outside on a clear night and wondered what they were looking at. No telescope required.
Moon phase calculator
Pick any date and see the phase, the age of the Moon and how much of it is lit.
The planets
Eight worlds, from scorching Mercury to icy Neptune, with the basics on each.
Constellations
Star maps of the patterns that are easiest to find from a city balcony.
Glossary
What do magnitude, zenith and opposition actually mean? Searchable list of terms.
Three tips for your first night
Give your eyes time. It takes 15–20 minutes in the dark for your eyes to adapt. Avoid looking at your phone screen, or switch it to a red night mode.
Start with the Moon and the bright planets. They are visible even from light-polluted cities, and binoculars already show craters on the Moon and the four largest moons of Jupiter.
Learn one pattern at a time. Find the Big Dipper or Orion first, then use them as signposts to the stars around them.