NASA's Mars InSight lander has nearly completed its nearly 300 million mile journey and is preparing for a landing on Mars on Monday afternoon, at about 3 pm Eastern time.
Why it matters: If successful, the InSight lander would become the first U.S. robot to land on Mars since the Curiosity rover arrived there in 2012. Unlike other spacecraft sent to Mars, this one is not designed to seek signs of life, but rather to investigate the planet's interior for clues into how certain planets, including Earth, formed about 4 billion years ago.