This week, our top Earth snapshots include an amazing Alaskan flyover, the Space Station's peaceful view of Russia and Eastern Europe -- and a red tide that's causing havoc in Florida.
The EPA maintains these controlled growth chambers (above) in Corvallis, Ore. They enable researchers to study the effects of air pollution, heavy metals and toxic substances on plant life.
This image of Alaskan forest land was shot from a Piper Cherokee aircraft by NASA scientists. They're conducting an aerial survey of 174,000 square miles of forests in the Alaskan interior, which are difficult to reach on the ground.
From the International Space Station, an astronaut captured this view of the southern Baltic sea. Russia, Poland and Lithuania are in the foreground, while Norway, Denmark and Sweden are seen in the distance.
California is suffering through a severe drought. This image, taken back in February, shows a dried-up riverbed along Highway 99 near Bakersfield.
A group of killer whales, also known as orcas, are seen swimming here in a tight pattern. NOAA scientists recently published a study of killer whale genetics, in which they reported that the creatures form distinct sub-populations that don't have much cross-breeding.
Typhoon Rammasun, AKA Glenda, battered the Philippines in mid-July. The storm is seen here in a satellite photo.
A sergeant major fish and an angelfish swim in a reef in the Florida Keys National Marine Sanctuary. These fragile underwater habitats are threatened by rising levels of carbon dioxide in the water, due to climate change.
A red tide off the coast of Florida has killed thousands of fish along with sea turtles and crabs, reports the AP. The algal bloom is caused by a marine organism, Karenia brevi, which is naturally occuring but toxic to humans and wildlife.