A Storm Seen From Space, Twice
On October 14, 2026, NASA's Earth Observatory published an Image of the Day that showed a hurricane the way most of us have never seen one. The image, built from VIIRS instrument data by Michala Garrison with a story by science writer Lindsey Doermann, actually contains two views of Hurricane Simon, taken on the same day by two different satellites.
The first view is the one we know: a classic portrait of a monster storm. Captured by the VIIRS instrument aboard the Suomi NPP satellite around 2:30 p.m. local time (20:30 UTC) on October 11, it shows Simon's perfectly formed eye staring up from a swirling mass of clouds off Mexico's Pacific coast. The second view is stranger. Taken in the early-morning hours of the same day by VIIRS on the NOAA-21 satellite, it reveals what the storm was doing far above its clouds: radiating ripples — atmospheric gravity waves — through the glowing upper atmosphere, like rings spreading across a pond.
A storm felt on the ground, and seen in the sky only by a satellite tuned to the faintest light: that is Hurricane Simon.
The Storm's Path and Power
Hurricane Simon was the latest in a long progression of tropical cyclones in the Eastern Pacific this season. It passed close to the Mexican coast as a Category 4 storm on October 11, 2026, creeping north-northwest with peak sustained winds reaching 250 kilometers per hour (155 mph).
When the Suomi NPP satellite captured its afternoon image, Simon's eye sat about 50 kilometers (30 miles) offshore, between the cities of Manzanillo and Puerto Vallarta. By that time, the National Hurricane Center reported, sustained winds had eased to about 210 kilometers per hour (130 mph) — still a powerful major hurricane — and the storm's inner core was brushing up against the coastline.
Mexico's geography played a quiet role in what happened next. The topography of the Sierra Madre mountains appeared to temper the storm's intensity somewhat and shrink the size of its wind field, the NHC noted. Mountains disrupt the warm, moist air feeding a hurricane, and in Simon's case the Sierra Madre acted like a brake. Even so, the storm remained dangerous: hurricane-force winds extended about 35 kilometers from its center, and tropical-storm-force winds reached 130 kilometers outward.
This was an unusually busy Eastern Pacific season. Scientists have pointed to the powerful El Niño ocean-warming phenomenon weakening the wind shear that normally tears storms apart, letting cyclones like Simon grow stronger and faster. For background on how this ocean event is supercharging storms, read our report on the record 2026 El Niño.
The Discovery Above the Clouds
The NOAA-21 image is the one that stopped scientists in their tracks. In the early morning hours of October 11 — while the hurricane churned below — the satellite's VIIRS day-night band recorded concentric ripples spreading outward high above the storm.
These are atmospheric gravity waves: enormous, slow-moving ripples in the air itself, radiating from the hurricane's core. They form through a chain reaction that starts at the ocean surface. Intense heat released as water vapor condenses near the eyewall — scientists call this latent heat — drives ferocious convection. Towering cumulonimbus clouds grow with updrafts so strong that they don't just push through the top of the troposphere; they send waves propagating upward through the stratosphere and into the mesosphere, the layer of atmosphere where meteors burn and airglow glows.
The waves are visible only because of a lucky combination of conditions. Gravity waves disturb the thin layer of glowing gases that produces airglow, creating subtle brightness variations that trace the ripples. Usually, strong winds at high altitude dissipate such disturbances before they can be seen, and reflected moonlight can wash out the delicate signal. On the night of October 10–11, 2026, upper-atmosphere winds cooperated and minimal illumination from the Moon let the airglow stand out — so the waves wrote themselves across the satellite's view.
Not That Kind of Wave: Gravity Waves Explained
The name causes confusion, so let's clear it up. Atmospheric gravity waves have nothing to do with gravitational waves — the ripples in spacetime created by colliding black holes and neutron stars that observatories like LIGO detect. Despite the similar name, they belong to entirely different corners of physics.
An atmospheric gravity wave is a buoyancy wave. Here's the simple version: imagine a parcel of air gets pushed upward. As it rises, it becomes cooler and denser than the air around it, so gravity pulls it back down. It overshoots, sinks too far, and gets pushed back up. The result is an oscillation — air bobbing up and down while the wave pattern itself travels outward or upward. Gravity is the "restoring force," like a weight on a spring. That is why these are called gravity waves.
They are everywhere, though usually invisible: air flowing over mountain ranges triggers them, and thunderstorms generate them too. Hurricanes, with their enormous energy, are among the most powerful natural generators on the planet. NASA captured a similar display above Super Typhoon Sinlaku earlier in 2026, and researchers have studied gravity waves radiating from intensifying tropical cyclones for years.
What makes them matter is that they carry energy and momentum upward. When gravity waves reach the stratosphere and mesosphere, they break — much like ocean waves breaking on a beach — depositing their energy into the thin air there. This process stirs the upper atmosphere's circulation, influences the polar vortex, and helps drive the vast, slow overturning of air tens of kilometers above our heads.
Airglow: The Sky's Faintest Light
To understand how a satellite "saw" these waves, you need to know about airglow. Airglow is a faint, diffuse light emitted by gases in the upper atmosphere, produced by chemical reactions — oxygen and sodium atoms releasing energy as they combine. It blankets the whole planet, day and night, though it is far too dim for human eyes to notice against the bright daytime sky.
Airglow is not the aurora, which is caused by solar particles striking near the poles; airglow is chemistry happening everywhere, all the time. NASA has called it the color of the upper-atmospheric wind, because watching it move reveals how the thin air high above us flows.
The VIIRS day-night band is one of the few instruments sensitive enough to photograph it. The same sensor that maps city lights and moonlit clouds can also pick up the ghostly glow of the mesosphere. But it is a delicate observation: the instrument detects reflected moonlight too, which can drown out the airglow signal. That night over the Pacific, a nearly moonless sky gave scientists an unusually clear window.
Satellites watching the upper atmosphere are quietly rewriting what we know about the sky. See how scientists watch Earth's fragile upper atmosphere in our report on this year's record ozone hole.
When the Storm Met the Coast
Simon never made a direct landfall, but staying offshore did not make it harmless. The major hurricane delivered heavy rain and flooding to coastal areas, including the port city of Manzanillo, Mexico's largest Pacific port, and raised the risk of mudslides in mountainous areas, according to news reports.
Mexico's preparations showed how seriously the storm was taken. Officials in Jalisco suspended classes in 22 coastal municipalities and evacuated residents from high-risk zones. In Puerto Vallarta, a resort city of nearly 300,000 people, businesses and hotels boarded up windows and moved visitors to shelters. Forecasters warned of waves up to 9 meters (30 feet) along the coast and rainfall totals of 10 to 20 inches across southwestern Mexico, with some areas possibly receiving up to 30 inches — enough to trigger life-threatening flooding and landslides in the mountains between the coast and the Sierra Madre.
By Sunday, October 12, Simon had weakened to a Category 3 storm and was drifting west, away from the coast, its forecast path remaining "very low confidence" as the storm continued to defy expectations. The immediate danger eased — but the satellite images remained, holding data scientists will study for years.
Why This Science Matters
The ripples above Simon are more than a curiosity — they are a missing link in how we model the atmosphere as a whole.
Weather happens in the troposphere, the lowest layer of air. But the atmosphere is one connected fluid. The energy a hurricane pumps upward in gravity waves doesn't just vanish; it shapes winds and temperatures in the stratosphere and mesosphere, which in turn influence weather patterns below — including the behavior of the polar vortex and even, indirectly, winter weather at the surface. Models that ignore this coupling are models with a blind spot.
There is also a forecasting angle. Research has shown that gravity waves are associated with the intensification of tropical cyclones. Spotting them from space won't replace hurricane-hunter aircraft or pressure readings, but it gives scientists another window into what a storm's core is doing — especially over open ocean, where direct measurements are scarce.
And there is the bigger picture. Simon struck during a year of mounting climate extremes — the same year the UN warned that the war on nature rages on ahead of the COP17 biodiversity summit, with fewer than half of global nature targets on track. Hotter oceans fuel stronger hurricanes; stronger hurricanes shake the sky harder. Understanding the full reach of these storms, from seafloor to mesosphere, is part of understanding the planet we are changing.
What's Next for Simon — and for Storm Science
As of mid-October, forecasters expected Simon to turn north and possibly enter the Gulf of California, with large swells battering Mexico's southwestern and west-central coasts in the meantime. The storm's slow, stalling motion — crawling at just a few miles per hour at times — prolonged the danger for coastal communities.
For scientists, the work is just beginning. The paired VIIRS images of Simon — one portrait of the storm, one of its atmospheric echo — will feed into studies of how tropical cyclones couple the lower and upper atmosphere. Each new observation refines the models, and each refined model sharpens our view of a warming world where Category 4 storms are arriving with unsettling regularity.
Hurricane Simon reminded us of something easy to forget: a storm is not just wind and rain at the surface. It is an engine that reaches from the warm ocean all the way to the edge of space — and now, thanks to satellites watching the night sky's faintest glow, we can watch it shake the sky itself.
