Why is the Exact Time important?
There are 1440 (24 x 60) minutes in a day while the Earth rotates 360. That means the Earth rotates 0.25 degree/minute. The field of view of a 26 mm eyepiece on ETX-90EC is 1.1 degrees. If the telescope is not tracking the target object, it will go out of view in 4.4 (1.1/0.25) minutes. Every one minute of error in the Autostar’s time, the target object will be off by seconds or 0.25. If the time is off by 4 minutes, the target object will be off by 1. Needless to say, if you do not set the Autostar’s time to the exact time, the telescope will not point to the exact location of your target object either. Remember, a half of a degree off here, a quarter of a degree off there, and you will miss the target. Your Polar alignment and Alt/Az alignment with affected. Your DC3-updated PC System Time DC3 is a freeware utility program that will synchronize your PC system time an atomic clock server to hundredth of a second. See Precision Time Source. Radio Digital Atomic clock NIST (National Ins
