Aegean airlines air hostesses take selfies after a news conference in Athens, Wednesday, March 28, 2018. In a deal worth up to $5 billion, Greek airline Aegean says it will buy 30 new Airbus aircraft, with the option of an additional 12, to upgrade its fleet as the country expects to break tourism records. The signing of the final purchase agreement is expected in June. (Photo by Petros Giannakouris/AP Photo)

A DC-10 air tanker delivers flame retardant to the Blue Cut fire in Wrightwood, Calif., Wednesday, August 17, 2016. A wildfire with a ferocity never seen before by veteran California firefighters raced up and down canyon hillsides, instantly engulfing homes and forcing thousands of people to flee, some running for their lives just ahead of the flames. (Photo by Alex Gallardo/AP Photo)

People release floating lanterns during the festival of Yee Peng in the northern capital of Chiang Mai, Thailand November 14, 2016. Yi Peng refers to the full moon day in the second month according to the Lanna lunar calendar (the twelfth month according to the Thai lunar calendar). Swarms of Lanna-style sky lanterns are launched into the air where they resemble large shoals of giant fluorescent jellyfish gracefully floating through the sky. The festival is meant as a time for tham bun, to make merit. Khom loi are made from a thin fabric, such as rice paper, stretched over a bamboo or wire frame, to which a candle or fuel cell is attached. When the fuel cell is lit, the resulting hot air is trapped inside the lantern and creates enough lift for the khom loi to float up into the sky. (Photo by Athit Perawongmetha/Reuters)

Little owl chicks in Northumberland, UK on August 19, 2018. Strutting up and down and barrelling through the air, these Little Owl chicks will soon be fending for themselves. The intense little birds were snapped by wildlife photographer Bill Doherty in his native Northumberland. The chicks have about seven or eight weeks to learn their survival skills before their parents drive them away to fend for themselves. (Photo by Bill Doherty/South West News Service)

Luis Hernan was always curious about how wireless technologies like radio are transmitted through the air. So after finishing up his studies in architecture, computer science, and design, Hernan decided to research these invisible signals through a PhD at Newcastle University. Hernan set up a system that turned the wireless signals around him into colourful, ghostlike images using long-exposure photography, allowing people to see the strength of the signals around them. (Photo by Luis Hernan)

A shrine maiden walks in the snow at the Tsurugaoka Hachimangu Shrine in Kamakura, near Tokyo, Thursday, November 24, 2016. Tokyo residents have woken up to the first November snowfall in more than 50 years. An unusually cold air mass brought wet snow to Japan's capital on Thursday. Above-freezing temperatures kept the snow from sticking, but forecasters said there could be an accumulation of up to 2 centimeters (1 inch). The last time it snowed in central Tokyo in November was in 1962. (Photo by Shizuo Kambayashi/AP Photo)

A ballet dancer practices in the sunshine at the Southbank skatepark in London on Monday, September 17, 2018, as Storm Helene is due to bring unseasonably warm weather in London and the south east, as the low pressure draws up warm air from the south. Forecasters have downgraded warnings that Helene could pose a risk to life when it hits this week – but warned coastal communities to stay vigilant. (Photo by Kirsty O'Connor/PA Wire)

A member of the wingsuit flyers duo, known as the Soul Flyers, is seen in mid-air as he catches up and flies into the open door of Pilatus Porter plane, piloted by Philippe Bouvier, after B.A.S.E. jumping off the Jungfrau mountain, 4158 meters, in Lauterbrunnen, Switzerland, October 13, 2017. French athletes Fred Fugen and Vince Reffet had 2.45 minutes and a free fall distance of 3200 meters to complete their project “Door In The Sky”, coordinated by Yves Rossy know as the “Jetman”. (Photo by Thibault Gachet/Reuters)