SUNSET: 
Observing Earth from the Moon
Ever wondered what it would be like to see the Earth from the Moon? Join Bob King as he explores this from the perspective of the Apollo 17 astronauts.
Explore the Night with Bob King
See All Eight Planets in One Night
Four planets are great, but how about eight? You can see them all in a single night in the next couple weeks — if you play your cards right.
Observe Changes on Mars
The nearby Red Planet displays remarkable changes every apparition. Whenever Mars approaches opposition, keep an eye out for some of these differences.
Find Jupiter's Moons - Interactive Observing Tool
Use our interactive observing tool to say which of the planet's four largest moons is which.
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.
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.
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.
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.
Mars Profiler: Which Side Is Visible?
To compare what you see on Mars with a map, you need to know which side of the planet you're looking at. Our handy Mars Profiler tells you that and more, for any date and time.
Explore the Night with Bob King
Uranus: In Seventh Heaven with Planet Seven
With our eyes often glued to the bright classical planets, Uranus is easy to overlook. Now well-placed for viewing at a convenient hour, why not pay this pale blue dot a visit the next clear night?
Explore the Night with Bob King
Saturn's Splendid Summer Show
It's showtime for the King of the Rings! Time to get your telescope out to see and share Saturn, which comes to opposition this week.
Explore the Night with Bob King
It's Not Over Till The Fast Planet Sinks
This week and early next will be your last chance to see five planets — six if you count Earth — at dawn.
Jupiter's Not-So-Great Red Spot
Astronomers don't know why Jupiter's iconic Great Red Spot has been gradually shrinking since the 1800s — or why the downsizing has accelerated during the past two years. Update: On May 15th, NASA released newly taken images of the Great Red Spot (at bottom below) to show its declining size…
How to See Jupiter: Big, Bright, and Beautiful
Jupiter, the King of Planets, is a captivating sight no matter how you look at it.
Viewing Saturn: The Planet, Rings and Moons
Viewing Saturn is an old favorite for every telescope user. Here's a guide to seeing all that you can see on the ringed planet.
A Saturn Almanac
Spectacular Saturn is a perennial favorite of telescope users everywhere. Click here to find printable data on the positions of Saturn's rings and planets.
Mercury, Messenger, and Observers
As the first images are released from Messenger's flyby of the innermost planet, previous ground-based observations are proving to be surprisingly accurate.
Catching the Messenger of the Gods
Mercury is a rewarding challenge for planetary astrophotographers, as this amazing image by Massachusetts amateur John Boudreau demonstrates.
Phenomena of Jupiter's Moons
Virtually any telescope will show Jupiter's four Galilean satellites and their interesting interactions with the planet or its shadow.
Jupiter: The Ultimate Observing Guide
Viewing the solar system¹s largest planet can be more than fun — even with a modest telescope, you can make observations of lasting scientific value.