ALT This image shows the International Space Station with NASA Earth Surface Mineral Dust Investigation (EMIT) sensor viewing Earth from space with EMIT logo in lower left and silhouetted pictograms representing applications of EMIT data, including forestry and biodiversity, fire, snow and ice, near shore water quality and algal blooms, geology, agricultural, landslides and natural hazards, water, and greenhouse gas emissions.

ALT Landsat 8 image of Arrecife Alacranes, Spanish for "Scorpion Reef," in the southern Gulf of Mexico taken in 2014. The reef is an oblong oval ringed with squiggles and dots of reef structures seen in light blue hues, surrounded by dark blue water.

ALT Astronaut image of pale blue tidal flats with branching, darker blue tidal channels of water flowing into the Great Bahama Bank from the bright blue Caribbean Sea, which is along the bottom of the image.

ALT Landsat 8 image of swirls of teal, turquoise, and green phytoplankton blooms in the Chukchi Sea off the Alaskan coast in 2018.

ALT Landsat 7 image of an intricate network of sand dunes on the ocean floor near the Great Bahama Bank. The dunes form blue, teal and green structures that look like waves and squiggles on the seafloor.

ALT Photographs of 5 different blue neustonic organisms on black backgrounds