Up until recently there was a real gap in good online orrery's Why this is I have no idea. However in the last year or so many have sprung out of the woodwork. Here is a list of the one's I've found:
The Most Beautiful Orrey Online
Beautifully put together, this orrery is a pleasure to watch as the planets and moons whir about all over the place.
The image is fixed with no zoom or messing about features, but you can turn on trails and change the centre between the earth and the sun. Update - this has been removed! I think it is still out there somewhere but I can't find it just yet.
The Most Beautiful Orrey Online
Beautifully put together, this orrery is a pleasure to watch as the planets and moons whir about all over the place.
The image is fixed with no zoom or messing about features, but you can turn on trails and change the centre between the earth and the sun. Update - this has been removed! I think it is still out there somewhere but I can't find it just yet.
Simple and Fun Orrery
This one is in development and has a simple look down view of the solar system. Can also put a marker on the earth and see when the sun goes up and down and allows you to understand where all the planets are in respect to your own position. A unique feature is the ability to see which planets are in retrograde at any moment. Speed it up and the fun starts! Since the view never changes (e.g. looking down on the ecliptic with earths northern tilt aways up) it helps to orient oneself - June-july earth at bottom, December- January earth at top.
Slick with new features to come
With billard ball planets this orrery has all the features you want with additional tours obviously in the pipeline. A nice neat application - and with the shift drag mouse, it all becomes 3D and you can view the solar system from all angles.
3D Fun
With lots of 3D features - and obviously more to come, this applications allows a full exploration of the solar system and it's bodies. It also allows you to see all the stars and constellations. Very impressive. Only slight downside is that that there are quite a few things to learn in order to use if fully, but otherwise really good fun.
Other Simulators that didn't quite capture my imagination (and so not linked to):
http://www.faustweb.net/ - just planets against stars - not many features.
http://burtleburtle.net/bob/physics/solar.html - just planet orbits being drawn.
http://www.cuug.ab.ca/kmcclary/goodjar/image.html - say what? I don't understand if/how this works!
http://orinetz.com/planet/animatesystem.php?sysid=QUQTS2CSDQ44FDURR3XD6NUD6 - cludgy - not enjoyable.
http://www.forgefx.com/casestudies/prenticehall/ph/solar_system/solarsystem.htm - requires latest version of shockwave player and allows nice 3D views of planets - but couldn't see how to make orbits move in short time I played with it.
http://janus.astro.umd.edu/SolarSystems/ - a nice orbit simulator but little control and no time information.
This one is in development and has a simple look down view of the solar system. Can also put a marker on the earth and see when the sun goes up and down and allows you to understand where all the planets are in respect to your own position. A unique feature is the ability to see which planets are in retrograde at any moment. Speed it up and the fun starts! Since the view never changes (e.g. looking down on the ecliptic with earths northern tilt aways up) it helps to orient oneself - June-july earth at bottom, December- January earth at top.
Slick with new features to come
With billard ball planets this orrery has all the features you want with additional tours obviously in the pipeline. A nice neat application - and with the shift drag mouse, it all becomes 3D and you can view the solar system from all angles.
3D Fun
With lots of 3D features - and obviously more to come, this applications allows a full exploration of the solar system and it's bodies. It also allows you to see all the stars and constellations. Very impressive. Only slight downside is that that there are quite a few things to learn in order to use if fully, but otherwise really good fun.
Other Simulators that didn't quite capture my imagination (and so not linked to):
http://www.faustweb.net/ - just planets against stars - not many features.
http://burtleburtle.net/bob/physics/solar.html - just planet orbits being drawn.
http://www.cuug.ab.ca/kmcclary/goodjar/image.html - say what? I don't understand if/how this works!
http://orinetz.com/planet/animatesystem.php?sysid=QUQTS2CSDQ44FDURR3XD6NUD6 - cludgy - not enjoyable.
http://www.forgefx.com/casestudies/prenticehall/ph/solar_system/solarsystem.htm - requires latest version of shockwave player and allows nice 3D views of planets - but couldn't see how to make orbits move in short time I played with it.
http://janus.astro.umd.edu/SolarSystems/ - a nice orbit simulator but little control and no time information.