Buying Guides
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Best Astrophysics Books for Beginners
Black holes, the Big Bang and stars for non-scientists, with the math level on every book.
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Best 50mm Telescopes
Small, light starter scopes for the Moon and the brightest planets.
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Best Telescopes for Viewing Planets
Scopes that show Saturn's rings, Jupiter's bands and the Martian poles.
Free Resources
Space Printables
Free PDF quizzes and worksheets for kindergarten to adult, with answer keys.
3D Space Models
Spin real maps of the Moon and planets built from NASA data. Find craters, landing sites, the rings of Saturn, Uranus and Neptune and the moons of Jupiter.
Latest
27 astronomy books for self study sorted into six stages, from no-math popular science to university astrophysics, with the math each book expects and free courses to pair with them.
Stars form when a cold cloud of gas and dust collapses under its own weight. Dense knots heat up, ignite,…
Table of Contents Quick answer The closest NASA mission to the Sun is Parker Solar Probe. It crossed into the…
The Mayan zodiac isn’t a wheel of twelve months. It’s the Tzolk’in, a 260-day calendar where your sign is set…
Arizona has some of the darkest skies in the lower 48, and almost nobody builds a planetarium trip around that.…
All 88 constellations with a star chart drawn from real star positions, the meaning of each name, pronunciation, best month to see it and free printable PDFs.
Find every Great Red Spot transit in your local time, see which ones are observable from your location and where the spot is on Jupiter right now.
Calculate your telescope’s resolving power, watch two stars split in a live diffraction simulator and see which double stars, lunar craters and planet details your telescope can show.
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