In this 2017 photo provided by Simon Pierce, Jonathan Green checks on a fin-mounted satellite tag on a whale shark in the Galapagos Islands area of Ecuador. Despite typically being bigger than a double-decker bus, the elusive whale shark has only tiny, almost useless teeth. It's also one of the least understood animals in the ocean. (Photo by Simonjpierce.com via AP Photo)

Mount Sinabung, a highly active volcano on Sumatra island, erupted several times this week. A volcanology agency has declared a danger zone of about four miles from the crater after seven farmers were killed and two others seriously injured. Here: A man carries his dog as a giant ash cloud rises from the Sinabung volcano in Karo, Indonesia on May 26, 2016. (Photo by Sutanta Aditya/Barcroft Images)

The Doppler on Wheels (DOW) vehicle scans a supercell thunderstorm during a tornado research mission, May 8, 2017 in Elbert County near Agate, Colorado. Doppler on Wheels (DOW) is a mobile doppler radar mounted on a truck that brings instruments directly into storms, allowing scientists to scan storms and tornadoes and make 3-D maps of wind and debris. (Photo by Drew Angerer/Getty Images)

Indigenous woven backpacks called guayare are seen in front of a house in Paraitepui village, before a walking excursion to Mount Roraima, near Venezuela's border with Brazil January 13, 2015. A mysterious table-topped mountain on the Venezuela-Brazil border that perplexed 19th century explorers and inspired “The Lost World” novel is attracting ever more modern-day adventurers. (Photo by Carlos Garcia Rawlins/Reuters)

A Tengger tribesman prays at Mount Bromo during the annual Kasada ceremony in East Java on August 12, 2014. The Kasada ceremony is a festival held every 14th day of the Kasada month in the traditional Hindu lunar calender to honour Sang Hyang Widhi (God Almighty) and is based on the legend of Roro Anteng and Joko Seger from the Majapahit Kingdom, from which their Tengger tribe name originates. Hundreds of worshippers from the Tengger tribe offer food and livestock as a symbolic sacrifice which they throw into the crater for the blessings of safety and prosperity to their familyies and community. (Photo by Juni Kriswanto/AFP Photo)

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)

Sinabung mountain spews volcanic smoke in Tiga Pancur Village, Karo, North Sumatra, Indonesia, 09 June 2019. According to BNPB, Mount Sinabung erupted, blowing volcanic ash more than 7,000 meters high. Sinabung is one of the most active volcanos in Indonesia. It erupted in 2010 and since then killed 17 people in eruptions in 2014 and another nine people in 2016. (Photo by Sarianto Sembiring/EPA/EFE)

A runner traverses the route during the Mount Everest Challenge Marathon which winds past spectacular views of Everest and Kanchenjunga at Sandakphu National Park in the month of November 1995 near Darjeeling, India.