Long, narrow clouds, known as ship tracks, stood out against the backdrop of marine clouds blanketing much of the North Pacific Ocean. http://www.nasa.gov/sites/default/files/thumbnails/image/clouds_amo_2018238_lrg.jpg

A truck sprays water to reduce the dust as NASA's crawler-transporter 2 with the mobile launcher atop moves slowly along, on its trek to Launch Pad 39B. http://www.nasa.gov/sites/default/files/thumbnails/image/44343884472_899f141b0e_k.jpg

Over a mere four days this summer, snow from the previous winter melted into a pond of slush a glaciologist called a “snow swamp.” http://www.nasa.gov/sites/default/files/thumbnails/image/lowell_oli_2018207_lrg.jpg

Bright surface features on the dwarf planet Ceres known as faculae were first discovered by NASA's Dawn spacecraft in 2015. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22480.jpg

Astronaut Ricky Arnold, from aboard the International Space Station, shared this image of Hurricane Florence on Sept. 10, taken as the orbiting laboratory flew over the massive storm. http://www.nasa.gov/sites/default/files/thumbnails/image/florence.jpeg

Ever stared down the gaping eye of a category 4 hurricane? It's chilling, even from space. http://www.nasa.gov/sites/default/files/thumbnails/image/churning.jpeg

NASA completed the final test to qualify Orion’s parachute system for flights with astronauts, an important milestone on the path to send humans on missions to deep space. http://www.nasa.gov/sites/default/files/thumbnails/image/43736204525_ca280961ee_k.jpg

A Delta II rocket launches with NASA's ICESat-2 onboard, Saturday, Sept. 15, 2018, from Vandenberg Air Force Base in California. http://www.nasa.gov/sites/default/files/thumbnails/image/29759342597_1acc62974d_o.jpg

Astronaut Serena Auñón-Chancellor examines her eye with a Funduscope. http://www.nasa.gov/sites/default/files/thumbnails/image/iss056e096896_0.jpg

Just over a month into its mission, NASA's Parker Solar Probe has returned first-light data from each of its four instrument suites. These early observations show that each of the instruments is working well. http://www.nasa.gov/sites/default/files/thumbnails/image/01_wispr-crop.png

In the northern constellation of Coma Berenices lies the impressive Coma Cluster — a structure of over a thousand galaxies bound together by gravity. http://www.nasa.gov/sites/default/files/thumbnails/image/potw1838a.jpg

John W. Young (1930-2018), born on Sept. 24, was NASA's longest-serving astronaut and the only astronaut to fly missions in the Gemini, Apollo and Space Shuttle Programs. http://www.nasa.gov/sites/default/files/images/561110main_s65-19228_full.jpg

NASA's Solar Dynamics Observatory views our Sun in ten different wavelengths because each wavelength reveals different solar features. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22724.jpg

NASA still hasn't heard from the Opportunity rover, but at least we can see it again. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22549-16.jpg

During National Hispanic Heritage Month, we're celebrating the contributions of the brilliant Hispanic women and men of NASA. In this Feb. 2007 photo, astronaut Michael E. Lopez-Alegria, Expedition 14 commander, participates in a 6-hour, 40-minute spacewalk as construction continues on the International Space Station. http://www.nasa.gov/sites/default/files/thumbnails/image/iss014e13416_large.jpg

This Aug. 5 1968 image was taken aboard the MV Retriever in the Gulf of Mexico, where the Apollo 7 crew, Walter Schirra, Walter Cunningham and Donn Eisele practiced water egress procedures in preparation for the October 1968 mission. http://www.nasa.gov/sites/default/files/thumbnails/image/s68-46603.jpg

Aeronautics, the first A of the NASA acronym, has always been a part of the agency. http://www.nasa.gov/sites/default/files/thumbnails/image/9458072623_5c6cf2fa3f_o.jpg

International Space Station astronaut and former teacher Ricky Arnold works with a student-designed experiment using NanoRacks commercial science hardware. http://www.nasa.gov/sites/default/files/thumbnails/image/43010056595_3fc589b92d_k.jpg

International Space Station Commander Alexander Gerst has a better view of our home planet than most. http://www.nasa.gov/sites/default/files/thumbnails/image/45025340661_7b9f8f9402_k.jpg

The landing jets fire as the Soyuz MS-08 spacecraft lands with Drew Feustel, Ricky Arnold and Oleg Artemyev, members of the Expedition 55 and 56 crews onboard the International Space Station. http://www.nasa.gov/sites/default/files/thumbnails/image/30157908867_e926f3f976_k.jpg