Lake Powell has hit its lowest level ever. Despite the monsoons, like the flash floods that hit Grand Canyon over the weekend, water levels continue to drop.
Visible planets and night sky guide: Look for the moon close to Saturn tonight. Plus Jupiter is returning at dawn. Watch the new "this week's sky" video.
El Niño is here. But will it become supersized? NOAA says there's a 90% or greater chance for El Niño to become "very strong" between September and January.
What is this odd 'jellyfish' on Mars? Possibilities include a cosmic ray artifact, an electronic artifact and what astronomers call a "transient phenomenon." The image went viral this week!