If you've looked at Saturn through a telescope recently, clearly the planet is not its usual gorgeous self. Those famous rings are angled nearly edge-on to our line of sight, appearing like a spear through Saturn's midsection.
Like the rings, the orbits of Saturn's major satellites are also seen nearly edge-on this year. As a result, the satellites now pass in front of and behind Saturn, casting their tiny shadows onto the planet's face and ducking in and out of its shadow, just like the moons of Jupiter do.
Saturn is about twice Jupiter's distance from us, however, and only Titan is a match for Jupiter's Galilean moons in terms of size. Nevertheless, notes Belgian astronomer Jean Meeus, the classic guidebook Saturn by A. F. O. Alexander describes Titan's shadow on Saturn being seen "quite easily" in a small refractor as early as 1862.
Meeus calculated the Titan timetable below so that you can try for yourself. The dates and times are in Universal Time. Oc refers to an occultation of Titan behind Saturn's limb. Ec means eclipse in Saturn's shadow. Tr is a transit of Titan across Saturn's face. Sh refers to Titan casting its shadow onto the planet.
An occultation or eclipse begins when Titan disappears (D) or reappears (R). A transit or shadow passage begins at ingress (I) and ends at egress (E). Each event is gradual, taking several minutes.
|Titan and Its Shadow on Saturn|
|Apr. 5||9:21||Ec. D.||May 23||6:30||Ec. D.|
|Apr. 5||13:37||Ec. R.||May 23||12:06||Ec. R.|
|Apr. 13||7:22||Sh. I.||May 31||4:32||Sh. I.|
|Apr. 13||11:51||Sh. E.||May 31||10:00||Sh. E.|
|Apr. 21||8:20||Ec. D.||June 8||5:39||Ec. D.|
|Apr. 21||13:10||Ec. R.||June 8||11:31||Ec. R.|
|Apr. 29||6:22||Sh. I.||June 16||3:40||Sh. I.|
|Apr. 29||11:16||Sh. E.||June 16||9:18||Sh. E.|
|May 7||7:23||Ec. D.||June 24||4:50||Ec. D.|
|May 7||12:40||Ec. R.||June 24||10:53||Ec. R.|
|May 15||5:26||Sh. I.|
|May 15||10:39||Sh. E.|
If you manage to snap a shot of Titan crossing Saturn's disk, please share it with other visitors by posting it to our online photo gallery.