The Artemis II astronauts are settling back into life on Earth, but we're not quite tired yet of hearing about their amazing journey. There's a new PBS documentary now streaming on YouTube that dives into the Artemis program and the latest efforts to send humans to the moon again. Also this week, NASA shared some awesome images of a comet flying into the sun, the nonprofit American Rivers released its annual report on the most endangered rivers in the US and ESA posted a throwback image of Mars to highlight some interesting changes down on the surface. Here are the science stories that caught our attention this week. A comet grazes too close to the sun Earlier this month, a recently discovered comet made a close approach to the sun — but it couldn't handle the heat. NASA has shared incredible images of the encounter that took place on April 4, showing the comet exploding into dust as it swings around our star.…