Marty Graham 9:10 p.m., April 23
Tonight's Moon Promises Not to Steal Light from Fireworks
The moon is just past third-quarter phase tonight, and it won't rise until midnight. This and every July 4 (technically July 6 this year) is astronomically notable for the fact that it marks Earth's aphelion -- the time when our planet lies farthest from the sun (94.5 million miles.) In January, Earth is an almost insignificant three percent closer to the sun than it is now. On account of this minor irregularity, Northern Hemisphere summers tend to be slightly cooler than they otherwise would be. At the same time, the Southern Hemisphere, which experiences winter during our "summer" months, has winters that tend to be slightly cooler.