This handout photograph taken in April 2005 and obtained on August 18, 2026 from Greenland Institute of Natural Resources shows narwhals with their tuskd in Uummannaq, West Greenland. Narwhals have nature's only straight tusk, a single tooth up to three metres long so strange they were sold as magical unicorn horns during the Middle Ages. On August 18, 2026, a large international team of researchers announced they had solved a long-running mystery about the tusks: how they get their uniquely spiralled yet arrow-straight form. (Photo by Mads-Peter Heide JORGENSEN / Greenland Institute of Natural Resources / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / Greenland Institute of Natural Resources / Mads-Peter Heide Jorgensen " - HANDOUT - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

(FILES) French astronaut Sophie Adenot speaks to children from the International Space Station during a video call, at the Centre Nationale d'Etudes Spatiale (CNES), in Toulouse on June 3, 2026. Sophie Adenot became the first French female astronaut to venture outside the International Space Station for a spacewalk on August 18, 2026, accompanied by American astronaut Anil Menon. President Emmanuel Macron hailed Sophie Adenot's spacewalk, describing the event as a source of "French pride" and seeing the astronaut as "the face of all possibilities." (Photo by Ed JONES / AFP via Getty Images)

(L-R) German Interior Minister Alexander Dobrindt, German Minister for Research, Technology and Aerospace Dorothee Baer, Saxony-Anhalt's State Premier Sven Schulze and the Chairwoman of the DLR Executive Board Anke Kaysser-Pyzalla take part in the opening of the new Drone Safety Technology Center at the Cochstedt site of the German Aerospace Center (DLR), eastern Germany on August 18, 2026. (Photo by Ronny HARTMANN / AFP via Getty Images)

(L-R) German Interior Minister Alexander Dobrindt, German Minister for Research, Technology and Aerospace Dorothee Baer, Saxony-Anhalt's State Premier Sven Schulze and the Chairwoman of the DLR Executive Board Anke Kaysser-Pyzalla applaud during the opening of the new Drone Safety Technology Center at the Cochstedt site of the German Aerospace Center (DLR), eastern Germany on August 18, 2026. (Photo by Ronny HARTMANN / AFP via Getty Images)

Saxony-Anhalt's State Premier and main candidate of Germany's Christian Democratic Union (CDU) party in the upcoming Saxony-Anhalt state election Sven Schulze takes part in the opening of the new Drone Safety Technology Center at the Cochstedt site of the German Aerospace Center (DLR), eastern Germany on August 18, 2026. (Photo by Ronny HARTMANN / AFP via Getty Images)

The Chairwoman of the DLR Executive Board Anke Kaysser-Pyzalla speaks during the opening of the new Drone Safety Technology Center at the Cochstedt site of the German Aerospace Center (DLR), eastern Germany on August 18, 2026. (Photo by Ronny HARTMANN / AFP via Getty Images)

Members of Germany's Federal Network Agency (L, Bundesnetzagentur) responsible for Germany's essential electricity, gas, telecommunications and postal infrastructures, and of the German police (R) take part in the opening of the new Drone Safety Technology Center at the Cochstedt site of the German Aerospace Center (DLR), eastern Germany on August 18, 2026. (Photo by Ronny HARTMANN / AFP via Getty Images)

Saxony-Anhalt's State Premier and main candidate of Germany's Christian Democratic Union (CDU) party in the upcoming Saxony-Anhalt state election Sven Schulze takes part in the opening of the new Drone Safety Technology Center at the Cochstedt site of the German Aerospace Center (DLR), eastern Germany on August 18, 2026. (Photo by Ronny HARTMANN / AFP via Getty Images)