Maybe I shouldn't have started this blog now, not with everything that's been going on.

I’ll continue with the Computer Science students’ astronomy software thesis that they showed me yesterday.

Next up in the list of animations they showed me (we’re going alphabetically here) were the Galilean moons of Jupiter. I saw the animation where the four moons are circling around the planet as seen from a point a little above the orbits.

My only comment on this was that it seemed to be a rehash of the same animation of four bodies rotation around a central body used in showing the Asteroid Belt. Jupiter was even depicted as blotchy red. I voiced my concern that students who are not listening to the audio or reading the text would think that he’s looking at the Sun, Mercury, Venus, Earth and Mars.

A quick image search on the net gave them the more recognizable view of Jupiter with the parallel concentric zones and the one and only crimson feature, the Great Red Spot. I told them if they used that skin for the sphere it would not be mistaken for the Sun anymore.

After that, there was the definition of the inferior planets. It was, basically, again the same animation as above. My suggestion here was that since the keyword here when grouping together Mercury and Venus is an “orbit” inside that of the Earth, they should have imaginary lines the represent the larger and smaller paths around the Sun.

Following in the sequence was the common phenomenon of occultation. Because the event was just like an eclipse but concerning not the Sun but a planet or star and the Moon, there were again two views of this, as seen from outside of the Earth, and as seen from the Earth.

The outer space view was good, except for a minor fault that I also found with the eclipses. The animation could be played and paused, but there was no specific button to make it easy for the user to stop at the exact moment of eclipse, or in this case, occultation. This would have been especially useful here, because since there are several stars shown in the background, there might be some students who would not read the explanation and not notice what actually happens during the occultation.

Just as an eclipse happens when the Earth, Sun and Moon are in a line, occultation happens when the Moon is between the Earth and a star or the Earth and a planet, thus covering the object from view on the other side of the Moon from the Earth. It would have been nice if this imaginary line of occurrence could be illustrated also. There could even be an option for the animation to proceed without pausing at the critical juncture.

There was also one major error with their view of occultation as seen from the Earth. The moon was shown as rotating. I had to remind them that the Moon is always facing the Earth, or has a time of rotation equal to its period of revolution.

Lastly, I also had to tell them to include in the text the significance of occultation, that with photographs through the telescope while the star or planet is near the edge of the Moon, experimental measurements and readings could be taken to prove the bending of the light from the object by the gravity of the Moon, that because of this the object can still be seen even when it is actually already behind the Moon.