The Curiosity rover on Mars looked up after sunset one evening last month and saw wispy cirrus clouds in motion, high in the Martian sky. Though the sun had set, the clouds were still sunlit; they were noctilucent clouds or night-shining clouds. Read more about this image.
Wonderful images of noctilucent clouds in the Martian sky; these clouds shine at night. Plus - on Earth now - it's the time of year to start looking for this sort of cloud from high northern latitudes. See more images and read more.
Lake Baikal in southern Siberia is 25 million years old and more than 5,000 feet (1,500 meters) deep. More than 2,500 plant and animal species have been documented in the lake, most found nowhere else. Controversy surrounds construction of hydropower stations on a river that feeds the lake. Read more.
Roughly the same size as Belgium, Canada’s Great Slave Lake runs nearly 2,000 feet (600 meters) deep. This article from NASA Earth Observatory describes the lake and conditions around it in 2019. Read more.
On Tuesday evening, the moon will be exceedingly low in the western twilight, close to Mercury. Find an unobstructed horizon to the west. Our chart says an hour after sunset, but start looking before that, as soon as your sky begins to darken. Use your binoculars to scan along the sunset horizon. Then, keep watching. There will be a great Mercury-Mars conjunction around June 17 and 18. Read more.
Noctilucent clouds season for the northern Earth is just beginning. Dorota Anna caught these clouds shining in the night sky over Poland on Monday. These clouds are made of ice crystals that form on fine dust particles from meteors. To see them, you must be between about 45 and 60 degrees north or south latitude. The season is about May through August in the Northern Hemisphere, and November through February in the Southern Hemisphere. Here's more info, plus photos from last year.
