NASA satellite maps autumn colour as it sweeps across the Northern Hemisphere

PACE spacecraft is the first to track all three leaf pigments across the planet every day or two

By LineZotpaper AI staff

Published26 October 2026

Read Time3 min

Illustration: NASA satellite maps autumn colour as it sweeps across the Northern Hemisphere

NASA's PACE satellite has captured this autumn's leaf colour as it spread from the high latitudes toward the equator, showing red foliage peaking in New England, northern Canada and northern Russia in late September before shifting into the Mid-Atlantic, Mongolia and northern China in early October.

The maps, released by NASA's Earth Observatory, measure vegetation "redness" using the Ocean Color Instrument (OCI) on the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite. Between September 29 and October 4, the reddest areas appeared in northern and eastern Russia, northern Alaska and northern Canada. During the following week, October 5 to 11, the wave shifted equatorward, with strong colour in the Mid-Atlantic, the US Southeast, southern Russia, China and Mongolia. In New England and upstate New York, redness began to fade even as it spread across much of the Midwest and the Mid-Atlantic.

OCI observes the planet daily at 286 spectral bands, including groups of wavelengths that let scientists track the pigments behind autumn colour: anthocyanins (reds), carotenoids (yellows and oranges) and chlorophylls (greens). Measuring how much red, orange and yellow forests show compared with green reveals where leaves are changing and when colour peaks. PACE is the first satellite able to measure all three pigments across the entire planet every day or two.

"It's the ability to collect time-series data of anthocyanins and carotenoids everywhere on Earth repeatedly that is game-changing," said Karl Huemmrich, a vegetation scientist at the Goddard Earth Sciences Technology and Research II center at the University of Maryland, Baltimore County, and a PACE science team member.

The satellite's eye is sharp enough to pick out individual ridgelines. A separate image from Landsat 9, captured on October 3, shows intensely red foliage around Ripton, Vermont, around the peak of redness for the region. The reddest areas, such as the Adirondacks and the Green and White Mountains, are dense with sugar maples and red maples. Marshy tundra in northern Alaska, Canada and Russia likely owes its bright reds to blueberries, bilberries, sedges, mosses and grasses.

Not every red patch is a fall colour, NASA notes: crops in some agricultural areas show high anthocyanin levels as they age and after harvest, and clouds can create gaps in the data.

The PACE team is asking the public to help verify what the satellite sees. As part of GLOBE's North American Phenology Campaign, NASA data scientist Skye Caplan has been posting weekly foliage maps, and the team wants ground photos of fall foliage.

"Changes in pigments can also occur when vegetation is stressed due to drought or insect damage," Caplan said, noting that stress may explain high redness in agricultural regions of Brazil, Australia and Canada that does not track seasonal changes. "The more photos we can get from the ground, the better."

The observations are expected to support research into how the timing of spring greening and autumn senescence is changing and how vegetation affects the global carbon cycle.

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Analysis

Why This Matters

PACE is the first satellite to measure all three key leaf pigments across the whole planet every day or two, producing continuous time-series data where earlier sensors could only do more local, less frequent surveys.
The weekly maps give casual leaf-peepers a practical tool for planning foliage trips, while ground photos help scientists verify what the satellite detects.
Colour patterns are tied to plant stress and the timing of seasons, so the data feed research on shifting growing seasons and the global carbon cycle.

Background

The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite is a NASA Earth-observation mission. Its Ocean Color Instrument was built to study the oceans and atmosphere, but its 286 spectral bands also pick out the pigments in land vegetation.

Leaves change colour as autumn's shorter days and cooler temperatures lower chlorophyll levels; with the green molecule fading, yellow and orange carotenoids and red anthocyanins become visible. The pull of the season is not new: Japan's momijigari tradition of "red leaf hunting" goes back more than a millennium, and mentions of foliage trips began appearing in American records in the 19th century, when artists and poets such as Frederic Church and Emily Dickinson celebrated the colours of the Northeast.

Key Perspectives

Karl Huemmrich (vegetation scientist at the Goddard Earth Sciences Technology and Research II center at the University of Maryland, Baltimore County, and PACE science team member): says the satellite's repeated global measurements "allow us to determine peak redness and yellowness anywhere on Earth," calling the time-series data "game-changing."

Skye Caplan (NASA data scientist, GLOBE North American Phenology Campaign): says pigment changes can also signal stress from drought or insect damage, which may explain high redness in agricultural regions of Brazil, Australia and Canada, and urges public photo submissions: "The more photos we can get from the ground, the better."

What to Watch

Caplan's weekly foliage maps, posted through GLOBE's North American Phenology Campaign, as the colour wave continues toward the equator.
High redness readings in agricultural regions of Brazil, Australia and Canada, where Caplan says stress or crop ageing may be showing up as colour.
The public photo campaign, which the PACE team will use to "ground truth" the satellite data and refine its measurements of vegetation colour.

Sources

Hunting Red Leaves with Satellites · NASA

Checked

11 claims in this story checked against 1 source: 7 supported.

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SupportedNASA satellite maps show autumn colour shifting across the Northern Hemisphere.NASA: “The maps above show vegetation “redness” from September 29 to October 4 (left) and October 5 to 11 (right).”
SupportedPACE is the first satellite able to measure all three leaf pigments across the planet every day or two.NASA: “PACE is the first satellite capable of measuring all three key leaf pigments—anthocyanins, carotenoids, and chlorophylls—across the entire planet every day or two.”
Partly supportedRed foliage peaked in New England, northern Canada and northern Russia in late September, then shifted into the Mid-Atlantic, Mongolia and northern China in early October.NASA: “Red foliage appears to peak in New England, northern Canada, and northern Russia from September 29 to October 4, then spreads southward into the Mid-Atlantic, Mongolia, and northern China from October 5 to 11 (right).”
SupportedKarl Huemmrich said, “It's the ability to collect time-series data of anthocyanins and carotenoids everywhere on Earth repeatedly that is game-changing.”NASA: ““It’s the ability to collect time-series data of anthocyanins and carotenoids everywhere on Earth repeatedly that is game-changing,” said Karl Huemmrich”
SupportedSkye Caplan said, “Changes in pigments can also occur when vegetation is stressed due to drought or insect damage.”NASA: ““Changes in pigments can also occur when vegetation is stressed due to drought or insect damage,” said Caplan.”
SupportedSkye Caplan said, “The more photos we can get from the ground, the better.”NASA: ““The more photos we can get from the ground, the better,” Caplan said.”
SupportedOCI observes the planet daily at 286 spectral bands.NASA: “The hyperspectral OCI (Ocean Color Instrument) on NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite observes the planet’s oceans and vegetation daily at 286 spectral bands.”
Not in the sourcesPACE's satellite eye is sharp enough to pick out individual ridgelines.NASA: “The OLI (Operational Land Imager) on Landsat 9 captured an image (above) of intensely red foliage around Ripton, Vermont, on October 3, 2026, around the peak of redness in the region.”
SupportedA separate Landsat 9 image captured on October 3 shows intensely red foliage around Ripton, Vermont, near the region's peak redness.NASA: “The OLI (Operational Land Imager) on Landsat 9 captured an image (above) of intensely red foliage around Ripton, Vermont, on October 3, 2026, around the peak of redness in the region.”
Partly supportedCaplan said stress may explain high redness in agricultural regions of Brazil, Australia and Canada that does not track seasonal changes.NASA: “She noted that changes like these likely help explain why PACE measures high levels of redness in agricultural regions of Brazil, Australia, and Canada that don’t track closely with broader seasonal changes.”
Partly supportedThe observations are expected to support research into changing seasonal timing and vegetation's effect on the global carbon cycle.NASA: “Ground photos help scientists refine PACE’s observations of vegetation color, which the team hopes will eventually support several lines of research. These include how the timing of spring greening and fall senescence is changing, how vegetation changes affect the global carbon cycle”