What if the next photo you take of the sky becomes part of NASA research?
Clouds may seem familiar, as we see them every day, watch them change before a storm, and often reach for our phones when the sky puts on a spectacular show. But to scientists studying Earth from space, those clouds are much more than things to photograph.
This fall, NASA is asking people around the world to look up, take pictures of the clouds above them, and help researchers compare what satellites see from space vs. what we’re seeing from the ground below.
NASA is calling this request the PACE Clouds Challenge, and participating is easy!
What Is the PACE Clouds Challenge?
The PACE Clouds Challenge runs for one month from September 15 through October 15, 2026.
NASA scientists working with the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite are asking citizen scientists to collect cloud observations from the ground when the satellite passes overhead. These observations will help researchers cross-reference and verify the complex data PACE collects about Earth's atmosphere, climate, and oceans.
PACE launched from Cape Canaveral Space Force Station on February 8, 2024. The satellite provides a unique hyperspectral view of Earth every one to two days. One of its capabilities is helping scientists study how clouds and aerosols interact with sunlight, which is where your view from the ground becomes valuable.
Why Does NASA Need Photos From the Ground?
A satellite can provide an incredible view of our planet, but there is still a difference between looking down from space and looking up from the ground.
NASA's PACE Atmosphere lead, Dr. Andy Sayer, is particularly interested in comparing ground-based cloud observations with PACE data. Dr. Sayer and fellow researchers want to better understand how well the satellite identifies cloud cover, including areas where clouds are broken up or where cloud edges can be difficult to detect.
PACE's satellite measurements cover large areas, while a smaller ground-based observation can provide an important point of comparison. To put it simply, your photos offer another perspective.
Scientists are especially looking for GLOBE Clouds observations collected within a five-minute window of PACE passing overhead, which makes timing an important part of the challenge.
How to Participate in the PACE Clouds Challenge
You don't need specialized equipment or a scientific background to take part. You just need the GLOBE Observer app, a smartphone or compatible device, and the ability to get outside when PACE is scheduled to pass overhead.
Here's how to participate in the PACE Clouds Challenge:
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Download the GLOBE Observer app
Download the app and set up the PACE overpass alert for your location. The alert will help you know when the satellite is expected to pass overhead.
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Observe during daylight
Cloud observations for the challenge should be made only during daylight hours. Do not submit nighttime cloud observations for the challenge.
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Watch for your PACE alert
About five minutes before the PACE satellite passes overhead, head outside and get ready to make your observation. Remember, timing is critical! The timestamp for your observation is based on when you open the Clouds tool in the app, so don't open the Clouds tool until you're outside and ready to begin.
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Photograph the sky
Open the Clouds tool and complete the observation by taking all six cloud photos as directed by the app. These images provide researchers with a consistent view of the sky that can be compared with what PACE observes from space. Volunteers whose observations fall within the optimal observation window and include all six photos will receive a certificate of recognition when their observation is matched with the satellite.
Want to Go Above and Beyond?
There are a couple of additional ways you can make your observations even more useful during the PACE Clouds Challenge.
When completing your observation, consider adding the type of phone or device you're using in the Field Notes section below the Feature Photos options. This device information can help researchers understand how much of the sky is included in each photograph.
You can also submit multiple observations in a single day if PACE passes over your location more than once during daylight hours. Depending on where you live and the satellite's timing, you may have the opportunity to collect observations up to twice a day!
What Is PACE Studying?
The PACE satellite was designed to provide scientists with a detailed look at Earth's atmosphere, land, and oceans. Its hyperspectral capabilities can reveal information about tiny particles in the air, plants on land, and microscopic algae in the ocean.
For clouds and aerosols, PACE measures how they absorb and reflect sunlight, which can help researchers study cloud cover and cloud types, as well as the interactions between clouds and aerosols and their effects on Earth's climate.
Understanding clouds better can help scientists improve the way satellite data is interpreted and contribute to a better understanding of Earth's atmosphere and climate.
Ready to Look Up? A Small Observation Can Contribute to Big Science
Sometimes, participation starts with something as simple as looking up! You don't have to work at NASA or have a degree in atmospheric science to contribute to scientific research, just like you don’t have to be a meteorologist to get hyperlocal weather data at your home.
The PACE Clouds Challenge gives people an opportunity to make real-world observations from wherever they are and provide scientists with information they can't get from satellite data alone.
Download the GLOBE Observer app, turn on your PACE overpass alerts, and get ready to look up.
When researchers analyze the images from the satellite looking down with the images you take from the ground, these combined perspectives can help scientists better understand our planet. Get out there and look up!
PACE Clouds Challenge: Key Dates
- Challenge dates: September 15, 2026 – October 15, 2026
- Best observation window: Within five minutes of the PACE satellite passing overhead
- Observations: Daylight hours only
- Photos: Complete all six cloud photos in the GLOBE Observer app
- Where: Wherever you are when PACE passes overhead