Tomorrow Saturday March 18 the Moon will be closer to Earth than that it has been since 1993!

The "supermoon" appears 14 percent larger and 30 percent brighter than lesser full Moons (as always this is with weather permitting). A casual observer probably won't tell the difference.


This full Moon almost coincides with perigee (which is when the Moon is closest to Earth). That means a very large range of high and low ocean tides. The highest tides lag by a few days depending on your location. For example, here in San Francisco, CA the highest tide (6.5 feet) will be attained on March 22. Any storms at sea now can aggravate coastal flooding. Such an extreme tide is known as a perigean spring tide (spring from the German word springen – to "spring up," and not the spring season).

Try to catch the Moon near the horizon, and it can appear enormous. This is due to the famous “Moon illusion” where a Moon looks incredibly large when it is seen near trees, buildings or other foreground objects. You can check the times for Moonrise and Moonset for your area by going to these websites:

Sun or Moon Rise/Set Table for One Year: U.S. Cities and Towns

Sun or Moon Rise/Set Table for One Year: Locations Worldwide

For example, did you know we can see more than half the Moon from Earth? Yes we can actually see 59 percent (almost three-fifths)!

Why? The Moon's rotation is uniform but its rate of revolution is not. So sometimes we see just around the edge of each limb!

The images you see in this article is a small version of a half-gigabyte gigantic image of the Moon. This image was stitched together from images taken by a Moon-orbiting satellite called the Lunar Reconnaisance Orbiter.

P.S. Happy Mooning!