AstroSim stands for Astrophysics Simulations and is a collaborative visualization project in Second Life.

AstroSim comprises a software package that has been produced in a joint research project between the following groups:

• NII, the national Institute of Informatics, in Tokyo;
• NAOJ, the National Astronomical Observatory of Japan, also in Tokyo;
• IAS, the Institute for Advanced Study in Princeton, NJ, USA.

The primary objective of the project is the development of a visualization tool within Second Life, initially for playing back previous simulations, and ultimately for real-time visualization of simulations running elsewhere.

Capabilities of the AstroSim package include features such as zooming in and out, speeding up and slowing down the playback, as well as applying time reversal. A typical demonstration to show the power of these options can focus on a low-N system with high complexity, featuring the interactions of multiple double stars and triple stars.