AP Top Science News at 5:34 p.m. EDT

Lake Powell hits record low, threatening key water and electricity supply for millionsThe hidden politics of time: How clocks, calendars — and now-contentious time zones — came to bePersistent Etna ash shuts Sicily's busiest airport during peak holiday weekThe warming climate is forcing marathons to consider changes to keep runners coolColombia’s earthquake is déjà vu for Venezuelans. The government response is anything butFACT FOCUS: Trump makes false claims as he signs order urging revisions around childhood vaccinesRadiation vest tested on NASA moonshot can cut astronauts' exposure in solar storms, study suggestsMillions crowd Spanish cities to see country's first total solar eclipse in over a centuryMalaysian farmers, environmental groups call for rejection of GMO rice trialEarthquake