Thousands are journeying to the border, motivated by complicated personal and practical reasons. Plus, the sound of Mars.Read more:Migrants are crossing the U.S.-Mexico border in large numbers. Arelis R. Hernández rode along with Constable Roque Vela on a dusty road along the Rio Grande in South Texas to talk to some of the people trying to navigate the complicated policies at the border — and learn about why they’re trying to cross it. NASA’s Perseverance Mars rover is recording sound. Martian wind might not sound exciting, but hearing it stopped producer Bishop Sand in his tracks. The rover is continuing to record sounds, and NASA releases them in weekly files at https://soundcloud.com/nasa.