PLANET

It was quite a discovery in tropical waters to bring in a Greenland shark, which can live for more than 500 years, according to the National Oceanic and Atmospheric Administration.

Earth Day puts a spotlight on the planet’s health, and often makes us think about what we can do to help out.

China's space agency said the five-ton combination orbiter and rover fired its engine to reduce its speed, allowing it to be captured by Mars' gravity. “Entering orbit has been successful ... making it our country’s first artificial Mars satellite,” the agency announced. Tianwen, the title of an ancient poem, means “Quest for Heavenly Truth.”Landing a spacecraft on Mars is notoriously difficult. In 2011, a Mars-bound Chinese orbiter that was part of a Russian mission didn’t make it out of Earth orbit. AdBefore the arrival this week of the Chinese spacecraft and the UAE’s orbiter, six other spacecraft were already operating around Mars: three U.S., two European and one Indian.