The Gnome Experiment
Travelling gnom [yt]
Oceans' tides [yt]
Bay of Fundy [yt]
The Hopewell Rocks [yt] [Map]
GRACE-FO [yt]

north vs south sky [yt]
North Star [yt]
Sun's Path through months [yt]
Horizon Coordinates [yt]
Kanal Launch Pad Astronomy
Equatorial Coordinate System [yt]
Rotating sky explorer
Analemma [yt]
Sun calculator #1
Sun calculator #2
Sun calculator #3
Leapsecond.com
Leap second Wiki
Rocznik astronomiczny [do zadań]
Rocznik astronomiczny IGIK
Paralaksa [yt]
Parsek [yt]