This gorgeous 20-second exposure of lightning striking the Bay Bridge in San Francisco went viral in April 2012.
Star trails reveal the movement of the night sky over Crater Lake in Oregon.
Photographer Phil McGrew said this photograph of the International Space Station traversing the face of the moon was the most technically challenging photograph he's ever taken. The shot involved a lot of data triangulation to make sure McGrew would be in the right place to see the ISS cross, visible here as a series of tiny dots. "Even if you miss it by half a mile the space station wont be across the moon," McGrew told LiveScience.
The Milky Way shines over McWay Falls south of Big Sur, Calif. Photographer Phil McGrew pulled an "all-nighter" to get this shot.
The barest sliver of a moon rises over the Lick Observatory east of San Jose, Calif.
A vapor cone forms around an F-18 as the plane approaches the speed of sound during an airshow in San Francisco.
Monarch butterflies gather at Ardenwood Historic Farm in Fremont, Calif.
Sunlight turns the surf orange at Pfeiffer Arch in California. Around the winter solstice, light from the sunset streams through the opening in the arch.
Two Western Grebes "dance" on the water as part of their mating ritual. Photographer Phil McGrew waited for hours to capture the dance, which was over in seconds.
The moon rises behind the Golden Gate Bridge and over the TransAmerica Tower in San Francisco.