When the moon rises right after sunset Saturday, it will look as though it put on some weight, even though technically it is weightless.
The so-called perigee moon will appear an estimated 14 percent larger than usual, and roughly 30 percent brighter once it gets cooking.
That’s because it will be closer to the Earth than usual. The moon’s orbit is elliptical, somewhat like the Earth’s around the sun.
At perigee, by NASA’s calculation, it is about 30,000 miles closer to the Earth than it is at apogee, its farthest distance - 252,000 miles.
By fortunate coincidence, we will be treated to perigee moons again on Aug. 10 and yet again on Sept. 9. NASA says the Aug. 10 moon might be of special note because it reaches perigee at the same hour that it becomes “full.”
We can’t speak on what viewing conditions will be like on those August and September nights, but Saturday night they should be fabulous, clear, and without much view-obscuring water vapor in the air.
Incidentally, according to NASA, supermoons aren’t all that unusual, occurring about once every 13 ½ months. As for having three in a row, this will be first time since … last year.
For your daytime viewing on Sunday, a NASA rocket launch from Wallops Island, Va., should be visible here if conditions are right.
The Antares ORB2 will be on a mission to resupply the International Space Station. Launch time is 12:52 p.m. Sunday. According to NASA it should be visible here in the southeast sky 2 minutes after launch. See map for other information.