Warm air and sunlight beget warmer ocean waters and provoke blooms of the “grass of the sea”—phytoplankton. http://www.nasa.gov/sites/default/files/thumbnails/image/northsea_oli_2018125_lrg.jpg

The crew of the International Space Station snapped this image of the full moon on April 30, 2018, as the station orbited off the coast of Newfoundland, Canada. http://www.nasa.gov/sites/default/files/thumbnails/image/iss055e043612.jpg

In the darkness of the distant universe, these galaxies resemble glowing fireflies, flickering candles, charred embers floating up from a bonfire, and light bulbs softly shining. http://www.nasa.gov/sites/default/files/thumbnails/image/potw1819a.jpg

Galileo Galilei discovered Jupiter's moon Europa in 1610. More than four centuries later, astronomers are still making discoveries about its icy surface. http://www.nasa.gov/sites/default/files/thumbnails/image/europa_0.jpg

Each and every day NASA's Solar Dynamics Observatory (SDO) observes our Sun and relays observational data to scientists on Earth. http://www.nasa.gov/sites/default/files/thumbnails/image/sun_0.jpg

This image of the southern Greenland town of Narsaq was taken during an Operation IceBridge flight on Apr. 26, 2018. http://www.nasa.gov/sites/default/files/thumbnails/image/41959302461_15269fcfff_o.jpg

Astronaut Ricky Arnold took this selfie during the May 16, 2018, spacewalk. http://www.nasa.gov/sites/default/files/thumbnails/image/iss055e071596.jpg

NGC 1032 cleaves the quiet darkness of space in two in this image from the NASA/ESA Hubble Space Telescope. http://www.nasa.gov/sites/default/files/thumbnails/image/potw1820a.jpg

An Orbital ATK rocket rolls out to launch Pad-0A at NASA's Wallops Flight Facility on May 17, 2018, in advance of a May 21 launch from Wallops Island, VA. The Antares will launch a Cygnus spacecraft on a cargo resupply mission to the International Space Station. http://www.nasa.gov/sites/default/files/thumbnails/image/nhq2018051700452.jpg

The Orbital ATK Antares rocket, with the Cygnus spacecraft onboard, is seen at launch Pad-0A, Saturday, May 19, 2018, at Wallops Flight Facility in Virginia. Liftoff is currently targeted for 4:39 a.m. Eastern on Monday, May 21. http://www.nasa.gov/sites/default/files/thumbnails/image/41321485135_0e2afbdc65_o.jpg

The Orbital ATK Antares rocket, with the Cygnus spacecraft onboard, launches from Pad-0A, Monday, May 21, 2018 at NASA's Wallops Flight Facility in Virginia. Cygnus will deliver approximately 7,400 pounds of science and research, crew supplies and vehicle hardware to the International Space Station and its crew. http://www.nasa.gov/sites/default/files/thumbnails/image/42205330652_5f11bfa041_o.jpg

(GRACE-FO) mission launched onboard a SpaceX Falcon 9 rocket, Tuesday, May 22, 2018, from Space Launch Complex 4E at Vandenberg Air Force Base in California http://www.nasa.gov/sites/default/files/thumbnails/image/nhq201805220003_0.jpg

The GRACE Follow-On spacecraft launched onboard a SpaceX Falcon 9 rocket, Tuesday, May 22, 2018. http://www.nasa.gov/sites/default/files/thumbnails/image/nhq201805220015.jpg

This close-up image is of a 2-inch-deep hole produced using a new drilling technique for NASA's Curiosity rover. The hole is about 0.6 inches (1.6 centimeters) in diameter. This image was taken by Curiosity's Mast Camera (Mastcam) on Sol 2057. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22326-16.jpg

The swirling spiral to the lower left of the frame is far from the most interesting spectacle here — behind it sits a galaxy cluster. http://www.nasa.gov/sites/default/files/thumbnails/image/potw1821a.jpg

An active region rotated into view and sputtered with numerous small flares and towering magnetic field lines that stretched out many times the diameter of Earth. http://www.nasa.gov/sites/default/files/thumbnails/image/sputteringsun.jpg

Astronomers have discovered evidence for thousands of black holes located near the center of our Milky Way galaxy using data from NASA's Chandra X-ray Observatory. http://www.nasa.gov/sites/default/files/thumbnails/image/sgra_swarm_lg.jpg

This image from NASA's Mars Reconnaissance Orbiter shows Hale Crater, a large impact crater. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22465_0.jpg

See a jet stream speeding through Jupiter’s atmosphere in this new view taken by NASA’s Juno spacecraft. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22422.jpg

The Soyuz MS-07 spacecraft is seen as it lands with Expedition 55 crew members Anton Shkaplerov of Roscosmos, Scott Tingle of NASA, and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) near the town of Zhezkazgan, Kazakhstan on Sunday, June 3, 2018. http://www.nasa.gov/sites/default/files/thumbnails/image/42535970511_bc542c6efc_o.jpg