The Susquehanna River cuts through the folds of the Valley-and-Ridge province of the Appalachian Mountains in this photograph taken by the crew of the International Space Station. via NASA https://ift.tt/2xVzL90

On the northwestern coast of Madagascar, the salty waters of the Mozambique Channel penetrate inland to join with the freshwater outflow of the Betsiboka River, forming Bombetoka Bay. via NASA https://ift.tt/34X6O8G

This image is one of several global images of the Earth at night released in 2017. via NASA https://ift.tt/3eFAT0Z

This image shows a small portion of the Gulf Stream off of South Carolina as it appeared in infrared data collected by the Landsat 8 satellite in April 2013. via NASA https://ift.tt/2RY6Zvj

Fifty years ago, on April 22, 1970, people around the world marked the first Earth Day. via NASA https://ift.tt/3eCY1xa

NASA astronaut Jessica Meir gives a thumbs up after she, Roscosmos cosmonaut Oleg Skripochka and NASA astronaut Andrew Morgan landed in their Soyuz MS-15. via NASA https://ift.tt/3ajabYu

This artist’s illustration shows what Kepler-1649c could look like from its surface. via NASA https://ift.tt/34MXwfp

This image shows sample site Nightingale Crater, OSIRIS-REx’s primary sample collection site on asteroid Bennu. via NASA https://ift.tt/3b9y8CN

Equipped with visionary science instruments, the Mars Perseverance rover underwent an “eye” exam after several cameras were installed. via NASA https://ift.tt/3bhhd1z

Apollo 13 launched on April 11, 1970, on a journey to become the third crew to land on the Moon. The crew never made it. via NASA https://ift.tt/2wyrnf0