Professional dog walker Jon Lovette of Jonny Walkers walks with dogs at Crissy Field on October 19, 2011 in San Francisco, California.

A group of Ring Tailed Lemurs eat from a Thanksgiving spread at the San Francisco Zoo on November 23, 2011 in San Francisco, California. Fifteen lemurs at the San Francisco Zoo were treated to a Thanksgiving feast of green beans, a fruit salad made up of apples, bananas, grapes sweet potatoes and a turkey made out of monkey chow. (Photo by Justin Sullivan/Getty Images)

Apple Senior VP of Worldwide Marketing Phil Schiller talks about the display on the new iPad during an Apple product launch event at Yerba Buena Center for the Arts on March 7, 2012 in San Francisco, California. In the first product release following the death of Steve Jobs, Apple Inc. introduced the third version of the iPad (iOS 5.1; Processor is an Apple A5X ARM-based unit; Display 2048 x 1536 pixels; Camera is set at 5 megapixels and has a 5-element lens plus auto face-detection, auto focus lock and image stabilisation for video; Wi-Fi + 4G) and an updated Apple TV. (Photo by Kevork Djansezian/Getty Images)

This aerial photo shows the wreckage of the Asiana Flight 214 airplane after it crashed at the San Francisco International Airport in San Francisco, Saturday, July 6, 2013. (Photo by Marcio Jose Sanchez/AP Photo)

The Supermoon rises over houses in Olvera, in the southern Spanish province of Cadiz, July 12, 2014. Occurring when a full moon or new moon coincides with the closest approach the moon makes to the Earth, the Supermoon results in a larger-than-usual appearance of the lunar disk. (Photo by Jon Nazca/Reuters)

Suspension artist and LUSH Cosmetics employee Alice Newstead inspects shark hooks that she had pierced into her skin during a demonstration against the shark fin trade at a LUSH Cosmetic store on August 24, 2011 in San Francisco, California.

Crowds look on as the super moon rises behind the Fremantle War Memorial at Monument Hill on November 14, 2016 in Fremantle, Australia. A super moon occurs when a full moon passes closes to earth than usual, with the November 14th moon expected to be closer than it has been in over 70 years. (Photo by Paul Kane/Getty Images)