The stars of the globular cluster NGC 6441 sparkle peacefully in the night sky, about 13,000 light-years from the Milky Way’s galactic center. http://www.nasa.gov/sites/default/files/thumbnails/image/potw2022a.jpg

Exquisite layering is revealed emerging from the sand in southern Holden Crater. Sequences like these offer a window into Mars' complicated geologic history. http://www.nasa.gov/sites/default/files/thumbnails/image/pia23952.jpg

Japan's resupply ship, the H-II Transfer Vehicle-9 (HTV-9), is pictured attached to the International Space Station's Harmony module. http://www.nasa.gov/sites/default/files/thumbnails/image/iss063e024519.jpg

Like a wisp of green smoke, the aurora australis seemingly intersects with the Earth's airglow as the International Space Station orbited above the Indian Ocean halfway between Australia and Antarctica. http://www.nasa.gov/sites/default/files/thumbnails/image/iss063e025120.jpg

This illustration imagines the view from NASA's Cassini spacecraft during one of its final dives between Saturn and its innermost rings. http://www.nasa.gov/sites/default/files/thumbnails/image/pia22768.jpg

Looking deep into the universe, the Hubble Space Telescope catches a passing glimpse of the numerous arm-like structures that sweep around this barred spiral galaxy, known as NGC 2608. Appearing as a slightly stretched, smaller version of our Milky Way, the peppered blue and red spiral arms are anchored together by the prominent horizontal http://www.nasa.gov/sites/default/files/thumbnails/image/potw2023a.jpg

Launched on April 20, 2004, Gravity Probe B (GP-B) was a collaboration between Stanford University and NASA designed to test two previously untested aspects of Albert Einstein’s general theory of relativity. http://www.nasa.gov/sites/default/files/thumbnails/image/gpb.jpg

Seen here in incredible detail is the starburst galaxy formally known as PLCK G045.1+61.1. The galaxy, which appears as multiple reddish dots near the center of the image, is being gravitationally lensed by a cluster of closer galaxies, also seen in the image. http://www.nasa.gov/sites/default/files/thumbnails/image/potw2024a_0.jpg

This artist's concept shows an astronaut on Mars, as viewed through the window of a spacecraft. http://www.nasa.gov/sites/default/files/thumbnails/image/pia23900.jpg

Pilots Troy Asher and Wayne Ringelberg walk out of NASA’s Armstrong Flight Research Center’s (AFRC) hangar in Palmdale, California, toward the flight line. http://www.nasa.gov/sites/default/files/thumbnails/image/afrc2020-0063-15_orig.jpg

Pilots Troy Asher and Wayne Ringelberg walk out of NASA’s Armstrong Flight Research Center’s (AFRC) hangar in Palmdale, California, toward the flight line. http://www.nasa.gov/sites/default/files/thumbnails/image/afrc2020-0063-15_orig.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

NASA astronauts (from top) Chris Cassidy and Bob Behnken work on U.S. spacesuits. http://www.nasa.gov/sites/default/files/thumbnails/image/iss063e030609.jpg

In this image NGC 7027 resembles a jewel bug, an insect with a brilliantly colorful metallic shell. http://www.nasa.gov/sites/default/files/thumbnails/image/stsci-h-p2031d-f-1764x1249.png

On June 21, 2020, as the International Space Station orbited over Kazakhstan and into China, an external high-definition camera captures this picture of the solar eclipse shadowing a portion of the Asian continent. http://www.nasa.gov/sites/default/files/thumbnails/image/iss063e031761.jpg

This composite image, made from six frames, shows the International Space Station, with a crew of five onboard, in silhouette as it transits the Sun. http://www.nasa.gov/sites/default/files/thumbnails/image/50041214891_87bdab628c_o.jpg

We don’t see the beautiful spiral arms of galaxy NGC 5907 in this Hubble image because we are viewing it edge-on, like looking at the rim of a plate. It is for this reason that NGC 5907 is also known as the Knife Edge galaxy. http://www.nasa.gov/sites/default/files/thumbnails/image/potw2025a.jpg

Spacewalkers Bob Behnken (left) and Chris Cassidy (right) in the Quest Airlock on June 26, 2020, before beginning a spacewalk to replace batteries on one of two power channels on the International Space Station. http://www.nasa.gov/sites/default/files/thumbnails/image/ebir4gdxsaqaxnu.jpg

June 30 is Asteroid Day. http://www.nasa.gov/sites/default/files/thumbnails/image/2166_ds1palomar_opt.jpg

On June 26, 2020, NASA astronauts Bob Behnken and Chris Cassidy conducted the first of two spacewalks to swap batteries and upgrade power systems on the International Space Station. http://www.nasa.gov/sites/default/files/thumbnails/image/iss063e033443.jpg