1–10 of 14 results

Astronomical Tools

Interactive Sky Chart

Create a custom, naked-eye map of the whole sky for any place on Earth, at any time of day or night, on any date from 1600 to 2400.

Astronomical Tools

A Jupiter Almanac

Find information on observing Jupiter during its 2018 - 2019 apparition, including information on its moons and Great Red Spot transit predictions.

Astronomical Tools

Astronomical Almanac

When do the Sun and Moon rise and set? When does twilight end and begin? Which planets are up? Start your night of observing with our Astronomical Almanac.

Astronomical Tools

Find the Phase of the Moon

Learn the phase of the Moon tonight, the day you were born, or on any historical date.

Astronomical Tools

Find Jupiter's Moons - Interactive Observing Tool and App

Use our interactive observing tool to say which of the planet's four largest moons is which.

Types of Objects to Observe

Transit Times of Jupiter's Great Red Spot

Calculate when the Great Red Spot will cross Jupiter's central meridian — that's the best time to see the famous storm through your telescope.

Types of Objects to Observe

Find Saturn's Moons: Interactive Observing Tool and App

With help from our interactive JavaScript utility, you can always tell which of Saturn's brightest moons is which.

Types of Objects to Observe

The Elusive Moons of Uranus

Take the observing challenge: Find as many as five of the brightest moons of Uranus in a large backyard telescope using our interactive observing tool.

Astronomical Tools

Track Triton, Neptune's Largest Moon

Triton, Neptune's largest moon, is a tricky find. Our Triton Tracker observing tool can help users of moderate to large telescopes spot this distant moon.

Astronomical Tools

Telescope Calculator: How Does Your Telescope Perform?

Use this telescope calculator to tell you how changing out eyepieces and accessories will affect your telescope's performance.