A giant 'shadow' has been creeping across Mars for 50 years - and scientists aren't sure why
Yahoo • • science
Key Points:
- A large dark patch of ash and volcanic rocks in Mars' Utopia Planitia region has been expanding across the surface for the past 50 years, with its southern boundary moving at least 200 miles farther south.
- The dark area, first photographed by NASA's Viking probes in 1976 and recently imaged by ESA's Mars Express orbiter, is believed to be spreading at about 4 miles per year, though the exact cause remains uncertain.
- Scientists hypothesize that Martian winds may be either redistributing the ash or blowing away lighter ochre dust that previously covered the dark patch, but no definitive explanation has been confirmed.
- Utopia Planitia has been a focus of exploration since Viking 2's 1976 landing, with more recent investigations by China's Zhurong rover revealing evidence of a former ocean, possible climatic shifts, and significant buried ice deposits.
- The region's geological features, including large ground cracks called grabens, may provide insights into Mars' tectonic history and have implications for the search for extraterrestrial life.
