If the Moon Were Only 1 Pixel

A tediously accurate map of the solar system.

'The Scale of the Universe,' by Two Teenage Brothers

Another Flash animation of the size of the universe.

Solar System Explained From the Inside Out

An excellent image showing the scale of our solar system.

Scale Of The Universe

Great flash website that shows the scale of the universe.

Saturn’s Hexagon May Be Solar System’s Coolest Mystery

The Cassini spacecraft has returned the best images yet of the strange hexagonal jet stream that flows around the northern pole of Saturn.

First discovered by the Voyager spacecraft in the early 1980s, the hexagon remains a beautiful mystery to astronomers, and one they’ve been waiting for another shot to see for almost three decades.

Click here for more information.

WorldWide Telescope

The WorldWide Telescope (WWT) is a Web 2.0 visualization software environment that enables your computer to function as a virtual telescope—bringing together imagery from the best ground and space-based telescopes in the world for a seamless exploration of the universe.

Voyager 2 Probe Reaches Solar System Boundary

The Voyager 2 spacecraft has crossed an important space frontier called the termination shock, and in a few years may become the first object made by humans to travel outside the solar system.

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Galaxy Zoo

Welcome to GalaxyZoo, the project which harnesses the power of the internet - and your brain - to classify a million galaxies. By taking part, you'll not only be contributing to scientific research, but you'll view parts of the Universe that literally no-one has ever seen before and get a sense of the glorious diversity of galaxies that pepper the sky.

Orrery

An orrery or planetarium is a mechanical contrivance that reproduces the motions of the planets and, sometimes, of their satellites. Operated by hand using cranks or clockwork mechanisms. More information can be found here and here.

Interplanetary Transport Network

The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the solar system that require very little energy for an object to follow. The ITN makes particular use of Lagrange points as locations where trajectories through space can be redirected using little or no energy. These points have the peculiar property of allowing objects to orbit around them even though there is no material object at them.

Wikisky

Okay, this is not a math post per se, but who doesn't like astronomy? Wikisky can show you the stars above a given location at a certain time. Pan, zoom, browse and explore the night sky using a Google-Earth-like interface.