It’s time to start watching for Comet PANSTARRS, one of two comets to get excited about in 2013. Photo: This image provided by NASA shoaws the comet PANSTARRS as seen from Mount Dale, Western Australia on March 5, 2013. According to NASA on March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun's glare but should return and be visible to the naked eye by March 12. (Photo by AP Photo/NASA)

Alexandre Vinokourov of Kazakhstan from the T-Mobile Team is chased by eccentric german inventor Didi Senft dressed as the red devil during the stage 16 of the 92nd Tour de France between Mourenx and Pau on July 19, 2005, France. (Photo by Friedemann Vogel/Bongarts/Getty Images)

Max Gold, 20, of NYC, cruises on his skateboard as thousands gather on the National Mall for the March for Science on Saturday, April 22, 2017, in Washington, DC. Activists and scientists descend on the nation's capital to rally for environmental causes and government policies rooted in scientific research as part of the Earth Day and March for Science rallies. (Photo by Jahi Chikwendiu/The Washington Post)

Sheriffs' deputies look at wreckage from the crash of Virgin Galactic's SpaceShipTwo near Cantil, California November 2, 2014. A suborbital passenger spaceship being developed by Richard Branson's Virgin Galactic company crashed during a test flight on Friday at the Mojave Air and Space Port in California, killing one crew member and seriously injuring the other, officials said. (Photo by David McNew/Reuters)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

A newborn baby pangolin climbs the walls of a cage in Bangkok, Thailand April 20, 2011. The Thai custom office showed 175 pangolins they found hidden in a truck heading into Bangkok. (Photo by Damir Sagolj/Reuters)

Respect, Kronotsky nature reserve, Russia. The photographer’s cat, Ryska – her name means little lynx in Russian – stands outside their cabin and with aggressive posturing warns off a fox. In winter, foxes would regularly visit the cabin searching for food. If one peered in at the window, possible when the snow was deep, Ryska would sit on the other side, fur raised, and growl. When outside, she would hold her ground. The foxes were not always frightened and so encounters could be a sort of dance. (Photo by Igor Shpilenok/Unforgettable Behaviour/NHM)

Arctic treasure by Sergey Gorshkov (Russia). An arctic fox carries its egg trophy from a raid on a snow goose nest and heads for a suitable burial spot. Finalist 2017, Animal Portraits. (Photo by Sergey Gorshkov/2017 Wildlife Photographer of the Year)