Several applets written in Java and scripts in Javascript are available. For these to work you must not have switched off such capabilities in your browser.
- What's observable? - make an observing list
- A digital orrery - plan view of the Solar System
- The Galilean satellites of Jupiter
- The 8 main satellites of Saturn
- Julian date - calendar converter
- Date/time intervals (eg, for variable star min/max prediction)
- Equatorial coordinates & precession
- Camera field of view and star trail calculator
- Angle subtended, object size and distance - calculate 3rd from any 2
We are open to ideas for further applets that may be useful to observers. Please contact Sheridan Williams.
We also have a page about calculation accuracy, to raise awareness of the issues and to show that we take them seriously: click here.
We have discovered that there is a problem with Java 6 update 11 running on Windows Vista. If you have that combination and the applets do not work, update Java to the latest version at java.com.
