Using STK 10 to recreate Cassini Earth images

If you have been following space news recently you might have seen that, from Cassini’s orbit around Saturn, it was able to take pictures of Earth from 898 million miles away. This event is rare because Cassini must have been in total eclipse from Saturn so as not to damage its sensitive optics while viewing Earth. What makes this even trickier is that the Earth and the Sun are so close to each other in relation to Cassini. The image from Cassini is magnificent and can be viewed at, along with other photos taken from Mercury, which is 61 million miles from Earth. This unique event got me thinking … how easily could I recreate it using STK 10? I headed over to and grabbed the necessary SPICE file that represents the position of the satellite over time, which I loaded into STK. I then did a quick access calculation to see when Cassini would have been shielded from the Sun, and I had my answer! My pictures can be seen below: Want to try it yourself?  Download and install STK 10 here, get a free license here and download the scenario here (username: anonymous). If you have any questions about this scenario or our software, contact AGI.

Kevin Ten Eyck

Systems Tool Kit (STK)

The most important thing on your desktop.