The hunt for dark matter and dark energy in the universe is expanding.
The big picture: Gravity from dark matter holds gas and dust together in stars and galaxies while dark energy pushes galaxies away from one another. Together, scientists think they make up 95 percent of our universe but what exactly they are remains elusive.
The big picture: Heat warnings and watches are in effect for over 100 million people as a record-breaking heat wave sweeping the southern U.S. continues to expand. Meanwhile, air quality alerts have been issued for an estimated 80 million others as wildfire smoke from Canada chokes much of the Mid-Atlantic, Midwest, Ohio Valley and even the Southeast.
Firefighters in Canada are now battling 497 active wildfires across the country after 31 new blazes ignited, according to the latest data from the Canadian Interagency Forest Fire Centre.
The big picture: New figures show 3,023 fires have burned across some 19.7 million acres of land during what officials this week declared has been Canada's worst wildfire season on record.
Smoke from unprecedented wildfires in Canada triggered poor air quality alerts over swaths of the U.S. again on Wednesday, with multiple cities reporting some of the worst air pollution levels of any major city around the world.
The latest: While continuing to choke the Great Lakes region and the upper Midwest Wednesday, the low-lying smoke also drifted southeast and began affecting Ohio Valley and Mid-Atlantic cities.
Heat-related emergency room visits are spiking in Texas, as forecasters warn the dangerously high temperatures will continue to expand into the Lower Mississippi Valley and Mid-South through Thursday.
State of play: Texas saw an average of 837 heat-related emergency department visits per 100,000 from June 18-24 amid ongoing triple-digit temperatures in the record heat wave that's now in its third week — up from 639 visits per 100,000 ER visits for the same period last year, per the CDC.
Hundreds of sea lions and dolphins are washing up dead or sick on California beaches due to a toxic offshore algae blooms, officials warn.
Driving the news: The Marine Mammal Care Center, which serves Los Angeles County, is at full capacity as the nonprofit rescue organization responds to "an unprecedented number of animals" falling ill to a neurotoxin from the bloom, CEO John Warner said at a news conference Tuesday.
