The largest full moon of 2012 happens this Saturday, but it’s OK if you don’t really notice. The moon doesn’t really get bigger, it just gets closer to Earth.
At 8:40 p.m. Pacific Time on Saturday, according to the Griffith Observatory Sky Report, the moon will be at its closest point in its orbit to the Earth this year. (Accounting for the time zone difference, European moon-watchers will see it Sunday.) To be precise, Earth and moon will be just 221,801 miles apart — more than 17,000 miles closer than average.
NASA’s Science News calculates the moon’s appearance Saturday will be “as much as 14% bigger and 30% brighter than other full moons of 2012.”
Some call what’s known as a perigee full moon a “supermoon.”
The beautiful circle surrounding the moon in this image is caused by ice crystals suspended in the air. Known as a paraselenic circle, this rare phenomenon comes from moonlight reflecting in complex ways off the crystals. While the circle is commonly only seen in sections, in some cases, such as this one, it can stretch around the entire sky.
Those dark spots sitting underneath this water strider aren’t exactly shadows. They’re patches of darkness created from distorted light as the little insect walks on the water’s surface.
A shallow pond’s surface acts somewhat like a stretched elastic skin. Water striders (of the family Gerridae) are able to “walk” on top of this skin because the surface tension produces a small upward thrust that holds their tiny weight.
The insect’s feet depress the water’s surface, producing a dip that bends light rays away from it. This creates a zone where no light can reach. Reflected rays all get pulled together, creating an intensely bright rim around each darkened patch.
This image, taken in Strasbourg, France, features grey clouds framing an astounding rainbow with seven fainter rainbows trailing below it.
This infrequent effect, called a supernumerary rainbow, comes about when the raindrops generating a rainbow are particularly uniform in size. As the different light waves spread out, they interfere with one another and form areas of darkness or brightness. These appear as pastel fringes below a regular rainbow.