France's President Emmanuel Macron, center, Arnold Schwarzenegger, left, and Prime Minister of Belgium Charles Michel, right, pose for a photo in front of the Eiffel Tower while aboard a boat cruising on the Seine River after the One Planet Summit, Paris, Tuesday, Dec. 12.
An illustration comparing the giant penguin to an average person. Kumimanu biceae weighed about 220 pounds and was a bit shorter than 6 feet in height. It swam around off the coast of New Zealand between 55 and 60 million years ago.
A photographer looks at the night sky to see the annual Geminid meteor shower in northern Italy in December 2015. This year's shower coincides with a close-range visit by its parent asteroid.
Marco Bertorello/AFP/Getty Images
Forage fish like these at a Chilean processing plant are often used for fish meal used in aquaculture. But critics consider this inefficient and wasteful and worry it could deplete fish populations. Now several companies are developing protein substitutes to replace fish meal.
Julio Etchart/ullstein bild via Getty Images
Cavitation produces a bubble that rapidly collapses and becomes hotter than the sun's surface. The mantis shrimp uses it, and now so do food and drink firms, to improve flavors — from yogurt to beer.
Reinhard Dirscherl/ullstein bild via Getty Images
A Hubble Space Telescope image of the Ant Nebula. Astrophysicist Adam Frank spent last week at an international meeting in Hong Kong trying to understand the science of what these objects tell us about the last gasp of dying stars like the sun.
NASA, ESA and the Hubble Heritage Team
Michele Comisky of Vienna, Va., enrolled her 8-year-old son, Jackson, in a study to test the value of probiotics in preventing the gut distress often experienced when taking antibiotics.