Buying Guides
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Best Star Diagonals
Mirror or prism, 1.25 or 2 inch: the right diagonal for your scope.
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Best 50mm Telescopes
Small, light starter scopes for the Moon and the brightest planets.
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Budget Telescopes That Are Sneakily Powerful
Five low-cost scopes that perform well above their price.
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
Upcoming rocket launches from Cape Canaveral and Kennedy Space Center, with countdowns and viewing spots.
The closest star to Earth is the Sun, 8.3 light-minutes away. The closest star after that is Proxima Centauri, a…
The Sun affects Earth in two ways. Its steady light and heat drive photosynthesis, weather, ocean currents, day and night,…
Montana has two planetariums that open to the public on a regular schedule: the Taylor Planetarium in Bozeman and the…
Iowa has eight observatories where an ordinary person can walk up and look through a real telescope. Some are free…
The Ptolemaic constellations are the 48 star patterns catalogued by the astronomer Claudius Ptolemy in the Almagest, around 150 CE.…










