Precision matters, even in 47-year-old data. 🛰️ Several Landsat 2 and Landsat 3 Multispectral Sensor (MSS) products were recently reprocessed to correct brightness value errors first identified in early 2025. About 44,000 of these products were originally processed with incorrect gain and offset values, specifically in Band 4 and Band 5, which ended up looking brighter or darker than they should have. This reprocessing also fixed about 1,700 MSS products that had a second problem. A processing bug caused about 27,000 extra pixels per scene, roughly 22% of each image, to be mistakenly marked as cloud, mostly along cloud edges. It's a small fix with a big purpose. Correcting these issues reflects our ongoing commitment to providing high-quality data to the Landsat user community. Keeping decades-old imagery accurate matters just as much as collecting new data. It's what allows Landsat's 50+ year archive to remain a reliable resource for studying long-term change on Earth's surface. Reprocessed products are ready to download from USGS Landsat Data Access: ow.ly/BWEK50ZY72y 📸: This Landsat 3 MSS scene over the Los Angeles, California, area was reprocessed to correct brightness value errors. Smoke from wildfires can be seen rising from the Angeles National Forest in September 1979. Credit: USGS #Landsat #RemoteSensing

The eruption lasted hours. Its effects on rivers and ecosystems are still showing up more than 40 years later. 🌋 When Mount St. Helens erupted, it sent a massive wave of mud, water, and debris downstream, overwhelming the Toutle, Cowlitz, and Columbia Rivers with sediment. Parts of the Columbia Riverbed rose by nearly 30 feet. The rivers never fully reset. Today, some still carry sediment at rates tens of times higher than before the eruption, creating ongoing challenges for flood protection and fisheries. The land tells a different story, and it's one that genuinely surprised scientists. Before 1980, experts assumed the blast zone would take generations to recover. Instead, life came back much faster than predicted. Because the devastation wasn't uniform, pockets of surviving plants and animals became the seeds of entirely new habitats. Today, the diversity of life at Mount St. Helens exceeds what existed before the eruption. That discovery changed how scientists study recovery after disasters, not just at volcanoes, but after wildfires, floods, and other events worldwide. In 1982, Congress established the Mount St. Helens National Volcanic Monument, protecting 110,000 acres around the volcano as a living laboratory for studying long-term change. Landsat has been part of that story from the start, capturing land change recovery one pixel at a time for more than 40 years. Want to learn more? Explore 10 ways the Mount St. Helens eruption changed our world 👉 ow.ly/WNRZ50ZWsck 📸1: Mount St. Helens, as viewed from the Castle Lake Overlook 📸2: Landsat 9 image, acquired August 26, 2024, showing Mount St. Helens and the surrounding landscape. Shades of red and pink highlight vegetation regrowth, while the volcano’s north-facing crater and lakes formed by the eruption remain visible. Credit: USGS #EarthScienceWeek #MountStHelens #Landsat