Blooms are made up of naturally occurring algae, phytoplankton, and cyanobacteria that explode in number under the right conditions: warm temperatures, lots of nutrients and calm waters.

A giant iceberg approximately 1.5 times the size of Greater Paris broke off from the northern section of Antarctica's Brunt Ice Shelf on Feb. 26, 2021.

Italy's Mount Etna, one of the world's most-active volcanoes and the tallest active volcano in Europe, erupted twice in less than 48 hours, spewing a fountain of lava and ash into the sky.

The ESA Copernicus Sentinel-2 mission captured this view of New York City on Feb. 4, 2021.

A research team”the first to carry out a survey of global ice loss using satellite data”discovered that the rate at which ice is disappearing across the planet is speeding up.

Storm Filomena blanketed parts of Spain in thick snow, leaving half the country on red alert.

All eyes remain on the giant A-68A iceberg on its journey across the Southern Ocean. This image shows A-68A's movements using data from the Copernicus Sentinel-1 and Sentinel-3 missions.

Seasonal cues, such as warmer spring temperatures or cooler temperatures in the fall, tell animals when to migrate, when to mate, and when and where to find food.

This natural-color image was acquired by the Operational Land Imager (OLI) on the Landsat 8 satellite on Oct. 18, 2020.

Within 10 days, the East Troublesome fire had burned through more than 190,000 acres (77,000 hectares) and had become Colorado's second largest fire (by area) on record. As of Oct. 26, 2020, it was 15 percent contained.