NASA tracks US autumn colours with PACE, asks for ground photos to check the view
NASA’s October 26 Earth Observatory report shows how satellite measurements can follow changing leaf pigments across the United States, while field photographs help scientists interpret what those measurements mean. Its Vermont example is an October 3 Landsat 9 image; the report does not provide a live guarantee of colour at a particular viewpoint today.
News date: 2026-10-26 · Checked: 2026-10-26 (Asia/Bangkok)
NASA’s October 26 Earth Observatory report shows how satellite measurements can follow changing leaf pigments across the United States, while field photographs help scientists interpret what those measurements mean. Its Vermont example is an October 3 Landsat 9 image; the report does not provide a live guarantee of colour at a particular viewpoint today.
Three key points
- PACE compares leaf pigments repeatedly across broad areas.
- Early-October data showed colour shifting from parts of the Northeast toward the Midwest and Mid-Atlantic.
- GLOBE seeks ground observations to help check the satellite measurements.
Follow the signal, then check the landscape
PACE’s Ocean Color Instrument measures reflected light in 286 spectral bands. Scientists compare signals associated with red and green pigments over time to track vegetation changes, rather than relying on a single photograph to identify a regional peak.
NASA reports that redness in New England and upstate New York began fading during October 5–11 while it spread across much of the Midwest and Mid-Atlantic. The separate Landsat image shows red forested ridges and greener valleys around Ripton, Vermont, on October 3.
A red patch does not always mean autumn foliage
The GLOBE campaign’s weekly updates warn that crops can show strong red-pigment signals as they age or after harvest. NASA also notes that clouds can leave gaps and that drought or insect damage can influence pigments. These limits matter when interpreting a national map as a local travel guide.
The PACE team is seeking ground photographs through GLOBE to help validate observations. Useful observations include shrubs, grasses and crops as well as forests. The research aims to improve understanding of vegetation changes; the sources do not establish a new operational warning service for fire, disease or drought.
