Thursday was Earth's aphelion day, its farthest distance from the sun at 94.51 million miles. Did you feel the difference in the middle of summer? Probably not since our temperatures are determined by the angle of sunlight and the length of daylight instead of our distance from the sun.

Your calendar might have said that aphelion was on July 5, instead of July 4. That's because the precise timing of aphelion was at 10:06 p.m. PST on July 4, which would be in the morning for those in Europe. "Coordinated Universal Time" is the official time used for astronomical events and that is set to the prime meridian of 0 degrees longitude 鈥 seven hours ahead of us during daylight saving time and eight hours during standard time. (So, when are we going to be done with switching back-and-forth for daylight saving?)

Contributing columnist Nick Strobel is director of the William M. Thomas Planetarium at 优蜜传媒 College and author of the award-winning website .