On Sept. 4, 2019, a loose chain of tropical cyclones lined up across the Western Hemisphere. http://www.nasa.gov/sites/default/files/thumbnails/image/westernhemisphere_geos_2019246_lrg.jpg

Scientists with NASA's Mars 2020 mission and the European-Russian ExoMars mission traveled to the Australian Outback to hone their research techniques. http://www.nasa.gov/sites/default/files/thumbnails/image/pia23275_large.jpg

It's Back to School Week and NASA has activities to keep students motivated. http://www.nasa.gov/sites/default/files/thumbnails/image/grace_tf_1.jpg

NASA astronaut Mike Fincke works through a check list inside a mockup of Boeing's CST-100 Starliner during a simulation at NASA's Johnson Space Center on Aug. 21, 2019. http://www.nasa.gov/sites/default/files/thumbnails/image/jsc2019e050522.jpeg

This 2019 photo of Manhattan, taken by astronaut Nick Hague from aboard the International Space Station, shows a city totally recovered from the attack on September 11, 2001. http://www.nasa.gov/sites/default/files/thumbnails/image/nyc_2019.jpg

Mae Jemison, the first black woman in space, participated in crew egress training for Space Shuttle Endeavour's STS-47 mission during the Terminal Countdown Demonstration Test. http://www.nasa.gov/sites/default/files/thumbnails/image/ksc-392c-5029_fr-036.jpg

In this mage from June 2002, astronaut Franklin R. Chang-Diaz works with a grapple fixture during a spacewalk to perform work on the International Space Station. http://www.nasa.gov/sites/default/files/thumbnails/image/sts111-306-012_orig.jpg

Actor Brad Pitt speaks with NASA astronaut Nick Hague who is onboard the International Space Station, Monday, Sept. 16, 2019. http://www.nasa.gov/sites/default/files/thumbnails/image/48744814666_20e44539d3_k.jpg

This image shows sedimentary rock and sand within Danielson Crater, an impact crater about 42 miles or 67 kilometers in diameter, located in the southwest Arabia Terra region of Mars. http://www.nasa.gov/sites/default/files/thumbnails/image/pia23454.jpg

Because they lack stellar nurseries and contain mostly old stars, elliptical galaxies — Like Messier 110 — are often considered “dead” when compared to their spiral relatives. But scientists have spotted signs of a population of young, blue stars at Messier 110's center, hinting that this neighbor of our Milky Way may not be so “dead” after all. http://www.nasa.gov/sites/default/files/thumbnails/image/potw1937a.jpg

The gantry arms close around the Soyuz rocket after it was raised into vertical position on the launch pad, Monday, Sept. 23, 2019 at the Baikonur Cosmodrome in Kazakhstan. http://www.nasa.gov/sites/default/files/thumbnails/image/48781030082_d1740019f4_k.jpg

Tethys appears to be stuck to Saturn's A and F rings from this perspective. http://www.nasa.gov/sites/default/files/thumbnails/image/pia18284-1600x1200.jpg

In this image, a galaxy called ESO 243-49 is home to an extremely bright object called HLX-1. Circled in this image, HLX-1 is the most likely example of a black hole in the intermediate mass range that scientists have found. http://www.nasa.gov/sites/default/files/thumbnails/image/main-shredded-galaxy_0.jpg

Frank Rubio was selected by NASA to join the 2017 Astronaut Candidate Class and reported for duty in August 2017. http://www.nasa.gov/sites/default/files/thumbnails/image/jsc2017e067119.jpg

Expedition 60 astronaut Christina Koch photographed the Soyuz MS-15 crew ship ascending into space after its launch from Kazakhstan. http://www.nasa.gov/sites/default/files/thumbnails/image/iss060e080405_large.jpg

Today is my last Monday living on this orbiting laboratory and I’m soaking up my final views, said astronat Nivk Hague. http://www.nasa.gov/sites/default/files/thumbnails/image/efvugonx0aa9bmd_2.jpg

NASA's Pegasus Barge arrives at the Launch Complex 39 turn basin wharf at Kennedy Space Center in Florida to make its first delivery to Kennedy in support of the agency's Artemis missions. http://www.nasa.gov/sites/default/files/thumbnails/image/ksc-20190927-ph-mtd01_0086_large.jpg

NASA astronaut Nick Hague is seen outside the Soyuz MS-12 spacecraft after he landed in a remote area near the town of Zhezkazgan, Kazakhstan. http://www.nasa.gov/sites/default/files/thumbnails/image/48836217723_ad164e610d_k.jpg

Cosmologist Stephen Hawking changed our view of the universe with his remarkable theories and outreach even thought he suffered from ALS, which slowly paralyzed him over the years. http://www.nasa.gov/sites/default/files/thumbnails/image/3462939243_8986257667_o.jpg

After completing the first of 10 spacewalks to upgrade the station, astronaut Christina Koch, wrote: The great @Space_Station battery swap series of spacewalks is underway! http://www.nasa.gov/sites/default/files/thumbnails/image/egr-xqtw4aez5m2.jpg