Dark finger-like slope streaks extending across the dusty Martian surface in a region called Arabia Terra are seen in this NASA satellite photograph released on May 19, 2025. — NASA/Handout via Reuters WASHINGTON: Images taken of Mars from orbit dating back as far as the 1970s have captured curious dark streaks running down the sides of cliffs and crater walls that some scientists have construed as possible evidence of flows of liquid water, suggesting that the planet harbors environments suitable for living organisms. A new study casts doubt on that interpretation. Examining about 500,000 of these sinewy features spotted in satellite images, the researchers concluded they were created probably through dry processes that left the superficial appearance of liquid flows, underscoring the view of Mars as a desert planet currently inhospitable to life — at least on its surface. The data indicated that formation of these streaks is driven by the accumulation of fine-grain dust from the Martian atmosphere on sloped...