After some days with temperatures below freezing point, I was out skating at some lakes at the outskirts of Oslo in Norway. After a while I noticed something on the ice. To my astonishment it was a dead frozen frog.

Some of the best entries so far in the 2016 Insight Astronomy Photographer of the Year competition. There are two weeks left to enter, and the winners will be announced in September. Here: Aurora over Laksvatn Fjord, Laksvatn, Norway. The aurora borealis dances in the skies over the town of Laksvatn, with the Milky Way to the left. The image is a single shot with no compositing, only post-processing to bring out the aurora, and some colour corrections. The photographer Matt Walford said: “I love the way the northern lights look like they are just wistfully dancing over the fjord, framed by the mountains on either side”. (Photo by Matt Walford/National Maritime Museum)

Back dropped by planet Earth the International Space Station (ISS) is seen from NASA space shuttle Endeavour after the station and shuttle began their post-undocking relative separation May 29, 2011 in space. After 20 years, 25 missions and more than 115 million miles in space, NASA space shuttle Endeavour is on the last leg of its final flight to the International Space Station before being retired and donated to the California Science Center in Los Angeles. Capt. Mark E. Kelly, U.S. Rep. Gabrielle Giffords' (D-AZ) husband, has lead mission STS-134 as it delivered the Express Logistics Carrier-3 (ELC-3) and the Alpha Magnetic Spectrometer (AMS-2) to the International Space Station. (Photo by NASA via Getty Images)

A Kashmiri girl holds her brother in the doorway of their home while watching protesters shout pro-freedom and anti-Indian slogans during mourning and protests held in downtown Srinagar on August 22, 2016, following the killing of teenager Irfan Ahmed by security forces. Teenager Irfan Ahmed was killed after he was hit in the chest by a teargas canister fired by Indian security forces to quell pro-freedom protests in the Kashmiri capital on August 21. More than 60 civilians have been killed in clashes between protesters and security forces, and thousands more injured in the worst violence to hit the Himalayan region since 201. Indian-administered Kashmir has been in the grip of almost daily anti-India protests and rolling curfews sparked by the killing on July 8 of a popular rebel leader, Burhan Wani, in a gunfight with government forces. (Photo by Tauseef Mustafa/AFP Photo)

“Serengeti National Park encompasses 5,700 square miles of grassy plains and woodlands near the northern border of Tanzania, and is home to more than 3,500 lions grouped into a couple dozen prides. Photographer Nick Nichols and videographer Nathan Williamson made several extended trips to the Serengeti between July 2011 and January 2013, determined to break new visual ground in their coverage of the Serengeti Lions”. Photo: Cubs of the Simba East pride: too young to kill but old enough to crave meat. Adult females, and sometimes males, do the hunting. Zebras and wildebeests rank high as chosen prey in the rainy season. (Photo by Michael Nichols/National Geographic via The Atlantic)

Double tornadoes, lightning storms and rotating supercells – this is what it's like to chase storms for a year. These dramatic images show apocalyptic weather throughout 2014 from a lightning storm to a pair of rainbows. Roger Hill, 57, has been chasing storms in the United States for thirty years and runs a tour operation with his wife Caryn. Here: a hailstorm rolls over fields, on July 22, 2014, in South Dakota. (Photo by Roger Hill/Barcroft Media)

The UK VELUX Lovers of Light competition attracted 15,000 entries from amateur, professional and mobile phone photographers. Entrants were asked to create a landscape image which celebrates and captures daylight. The judges have whittled these down to a shortlist of ten finalists. The winner will be announced at the end of march with the snapper of the best shot winning a trip to Norway – which will be made during the summer period when the country experiences 24 hour daylight. Photo: “Carousel in the mist”; Prokoshko, Bosnia. (Photo by Marko Stamatovic/PA Wire)

Son doong cave is a cave in Phong Nha-Kẻ Bàng National Park, Bố Trạch district, Quảng Bình Province, Vietnam. Currently the biggest known cave in the world, the cave is located near the Laos-Vietnam border. Inside is a large, fast-flowing underground river.
In early August 2013, the first tourist group explored the cave on a guided tour at a cost of US$3,000 each. The group had six members from Australia, Norway, Russia and USA and spent 7 days and 6 nights for the tour. Next exploration trips will be arranged.