Will Dunham

Daily satellite observations have revealed a continued nighttime brightening globally due to artificial lighting, with important regional variations including a surge in sub-Saharan Africa and ​Southeast Asia alongside a deliberate dimming in Europe driven by concerns over energy conservation and light pollution.

As humankind moves toward the goal of establishing a long-term presence on the moon and Mars, the question of whether reproduction is possible in extraterrestrial environments may no longer be merely hypothetical. And new research using ​simulated microgravity conditions has identified some major challenges.

Dogs have been loyal companions to people since we made them our first domesticated animals, descending long ago from gray wolves - though precisely when, where and why have remained unanswered. New genetic ​research now is offering valuable insight, including identifying the earliest-known dog, dating to 15,800 years ago.

Robert Mueller, the no-nonsense former FBI chief who documented Russia's interference in the 2016 U.S. election and its contacts with Donald Trump's campaign but opted not to bring criminal charges against a sitting president, has died at age 81, his former law firm confirmed on Saturday.

Using ground-penetrating radar, NASA's Perseverance rover has detected underground remains of an ancient river delta on Mars in some of the oldest evidence yet obtained showing how water once ​flowed on the surface of Earth's planetary neighbor.

French President Emmanuel Macron said on Sunday ​he had asked Iranian President Masoud Pezeshkian ‌to put an immediate end to attacks against countries in the Middle East whether directly or ​through proxies, including in Lebanon and ​Iraq.

When Homo sapiens trekked out of Africa, our species encountered Neanderthal populations already inhabiting the vast expanses of Europe, Asia and the Middle East. As the presence of Neanderthal DNA in most present-day people shows, interbreeding occurred, though the circumstances have remained unclear.

A small object called the Adorant figurine discovered in a cave in Germany in 1979 - crafted roughly 40,000 years ago by some of the earliest people to establish a distinct culture in Europe - bears intriguing sequences of notches and dots. Numerous other objects produced by this same culture exhibit similar marks.

It was not an easy task for a team of dinosaur-hunting scientists to reach the remote site called Jenguebi in northern Niger deep in the Sahara Desert. It was fitting that the closest locality was named Sirig Taghat, meaning "no water, no goat" in Tamasheq, the local Berber language.

For more than a century, biology textbooks have stated that vision among vertebrates - people included - is built from two clearly defined cell types: rods for processing dim light and cones for bright light and color. New research involving deep-sea fish shows this tidy division is, in reality, not so tidy.