What is the smallest particle in the universe? (What about the largest?)

Whale shark health dependent on habitat, nutrition, and right mix of microbes: Study

National Geographic Science on Instagram: "Underwater volcanoes can support entire marine ecosystems, starting with the ocean's smallest organisms. #AmericasNationalParks is now streaming on @DisneyPlus and @Hulu."

Fahad Khan on Instagram: "The güiña (Leopardus guigna), the smallest wild feline in the Americas, which lives in forests in Chile and Argentina, has been reclassified on the Red List of the International Union for Conservation of Nature (IUCN) from “Vulnerable” to “Least Concern” as of October 2025. The change is due to more precise studies that place its population at around 100,000 individuals, and confirms that the species no longer meets the extinction risk criteria established by the IUCN.