Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
5 min read
New NASA Mission to Reveal Earth’s Invisible ‘Halo’
A new NASA mission will capture images of Earth’s invisible “halo,” the faint light given off by our planet’s outermost atmospheric layer, the exosphere, as it morphs and changes in response to the Sun. Understanding the physics of the exosphere is a key step toward forecasting dangerous conditions in near-Earth space, a requirement for protecting Artemis astronauts traveling through the region on the way to the Moon or on future trips to Mars. The Carruthers Geocorona Observatory will launch from NASA’s Kennedy Space Center in Florida no earlier than Tuesday, Sept. 23.
Revealing Earth’s invisible edge
In the early 1970s, scientists could only speculate about how far Earth’s atmosphere extended into space. The mystery was rooted in the exosphere, our atmosphere’s outermost layer, which begins some 300 miles up. Theorists conceived of it as a cloud of hydrogen atoms — the lightest element in existence — that had risen so high the atoms were actively escaping into space.
But the exosphere reveals itself only via a faint “halo” of ultraviolet light known as the geocorona. Pioneering scientist and engineer Dr. George Carruthers set himself the task of seeing it. After launching a few prototypes on test rockets, he developed an ultraviolet camera ready for a one-way trip to space.
Apollo 16 astronaut John Young is pictured on the lunar surface with George Carruthers’ gold-plated Far Ultraviolet Camera/Spectrograph, the first Moon-based observatory. The Lunar Module “Orion” is on the right and the Lunar Roving Vehicle is parked in the background next to the American flag. NASA In April 1972, Apollo 16 astronauts placed Carruthers’ camera on the Moon’s Descartes Highlands, and humanity got its first glimpse of Earth’s geocorona. The images it produced were as stunning for what they captured as they were for what they didn’t.
“The camera wasn’t far enough away, being at the Moon, to get the entire field of view,” said Lara Waldrop, principal investigator for the Carruthers Geocorona Observatory. “And that was really shocking — that this light, fluffy cloud of hydrogen around the Earth could extend that far from the surface.” Waldrop leads the mission from the University of Illinois Urbana-Champaign, where George Carruthers was an alumnus.
The first image of UV light from Earth’s outer atmosphere, the geocorona, taken from a telescope designed and built by George Carruthers. The telescope took the image while on the Moon during the Apollo 16 mission in 1972. G. Carruthers (NRL) et al./Far UV Camera/NASA/Apollo 16 Our planet, in a new light
Today, the exosphere is thought to stretch at least halfway to the Moon. But the reasons for studying go beyond curiosity about its size.
As solar eruptions reach Earth, they hit the exosphere first, setting off a chain of reactions that sometimes culminate in dangerous space weather storms. Understanding the exosphere’s response is important to predicting and mitigating the effects of these storms. In addition, hydrogen — one of the atomic building blocks of water, or H2O — escapes through the exosphere. Mapping that escape process will shed light on why Earth retains water while other planets don’t, helping us find exoplanets, or planets outside our solar system, that might do the same.
NASA’s Carruthers Geocorona Observatory, named in honor of George Carruthers, is designed to capture the first continuous movies of Earth’s exosphere, revealing its full expanse and internal dynamics.
“We’ve never had a mission before that was dedicated to making exospheric observations,” said Alex Glocer, the Carruthers mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It’s really exciting that we’re going to get these measurements for the first time.”
Download this video from NASA’s Scientific Visualization Studio.
Journey to L1
At 531 pounds and roughly the size of a loveseat sofa, the Carruthers spacecraft will launch aboard a SpaceX Falcon 9 rocket along with NASA’s IMAP (Interstellar Mapping and Acceleration Probe) spacecraft and the National Oceanic and Atmospheric Administration’s SWFO-L1 (Space Weather Follow On – Lagrange 1) space weather satellite. After launch, all three missions will commence a four-month cruise phase to Lagrange point 1 (L1), a location approximately 1 million miles closer to the Sun than Earth is. After a one-month period for science checkouts, Carruthers’ two-year science phase will begin in March 2026.
Artist’s concept of the five Sun-Earth Lagrange points in space. At Lagrange points, the gravitational pull of two large masses counteract, allowing spacecraft to reduce fuel consumption needed to remain in position. The L1 point of the Earth-Sun system affords an uninterrupted view of the Sun and will be home to three new heliophysics missions in 2025: NASA’s Interstellar Mapping and Acceleration Probe (IMAP), NASA’s Carruthers Geocorona Observatory, and NOAA’s Space Weather Follow-On – Lagrange 1 (SWFO – L1). NASA’s Conceptual Image Lab/Krystofer Kim From L1, roughly four times farther away than the Moon, Carruthers will capture a comprehensive view of the exosphere using two ultraviolet cameras, a near-field imager and a wide-field imager.
“The near-field imager lets you zoom up really close to see how the exosphere is varying close to the planet,” Glocer said. “The wide-field imager lets you see the full scope and expanse of the exosphere, and how it’s changing far away from the Earth’s surface.”
The two imagers will together map hydrogen atoms as they move through the exosphere and ultimately out to space. But what we learn about atmospheric escape on our home planet applies far beyond it.
“Understanding how that works at Earth will greatly inform our understanding of exoplanets and how quickly their atmospheres can escape,” Waldrop said.
By studying the physics of Earth, the one planet we know that supports life, the Carruthers Geocorona Observatory can help us know what to look for elsewhere in the universe.
The Carruthers Geocorona Observatory mission is led by Lara Waldrop from the University of Illinois Urbana-Champaign. The Space Sciences Laboratory at the University of California, Berkeley leads mission implementation, design and development of the payload in collaboration with Utah State University’s Space Dynamics Laboratory. The Carruthers spacecraft was designed and built by BAE Systems. NASA’s Explorers and Heliophysics Projects Division at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, manages the mission for the agency’s Heliophysics Division at NASA Headquarters in Washington.
By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Share
Details
Last Updated Sep 18, 2025 Related Terms
Goddard Space Flight Center Heliophysics Heliophysics Division NASA Directorates Science & Research Science Mission Directorate Uncategorized Explore More
5 min read NASA’s Hubble Sees White Dwarf Eating Piece of Pluto-Like Object
Article
3 hours ago
6 min read NASA’s IMAP Mission to Study Boundaries of Our Home in Space
Article
1 day ago
4 min read NASA Interns Apply NASA data to Real-World Problems to Advance Space Research and Aerospace Innovation
Article
1 day ago
Keep Exploring Discover More Topics From NASA
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By Space Force
The stand-up synchronizes acquisition efforts for critical space system capabilities and works together with STARCOM Space Deltas to improve mission readiness.
View the full article
-
-
-
By NASA
The IAU (International Astronomical Union), an international non-governmental research organization and global naming authority for celestial objects, has approved official names for features on Donaldjohanson, an asteroid NASA’s Lucy spacecraft visited on April 20. In a nod to the fossilized inspiration for the names of the asteroid and spacecraft, the IAU’s selections recognize significant sites and discoveries on Earth that further our understanding of humanity’s origins.
The asteroid was named in 2015 after paleoanthropologist Donald Johanson, discoverer of one of the most famous fossils ever found of a female hominin, or ancient human ancestor, nicknamed Lucy. Just as the Lucy fossil revolutionized our understanding of human evolution, NASA’s Lucy mission aims to revolutionize our understanding of solar system evolution by studying at least eight Trojan asteroids that share an orbit with Jupiter.
Postcard commemorating NASA’s Lucy spacecraft April 20, 2025, encounter with the asteroid Donaldjohanson. NASA’s Goddard Space Flight Center Donaldjohanson, located in the main asteroid belt between the orbits of Mars and Jupiter, was a target for Lucy because it offered an opportunity for a comprehensive “dress rehearsal” for Lucy’s main mission, with all three of its science instruments carrying out observation sequences very similar to the ones that will occur at the Trojans.
After exploring the asteroid and getting to see its features up close, the Lucy science and engineering team proposed to name the asteroid’s surface features in recognition of significant paleoanthropological sites and discoveries, which the IAU accepted.
The smaller lobe is called Afar Lobus, after the Ethiopian region where Lucy and other hominin fossils were found. The larger lobe is named Olduvai Lobus, after the Tanzanian river gorge that has also yielded many important hominin discoveries.
The asteroid’s neck, Windover Collum, which joins those two lobes, is named after the Windover Archeological Site near Cape Canaveral Space Force Station in Florida — where NASA’s Lucy mission launched in 2021. Human remains and artifacts recovered from that site revolutionized our understanding of the people who lived in Florida around 7,300 years ago.
Officially recognized names of geologic features on the asteroid Donaldjohanson. NASA Goddard/SwRI/Johns Hopkins APL Two smooth areas on the asteroid’s neck are named Hadar Regio, marking the specific site of Johanson’s discovery of the Lucy fossil, and Minatogawa Regio, after the location where the oldest known hominins in Japan were found. Select boulders and craters on Donaldjohanson are named after notable fossils ranging from pre-Homo sapiens hominins to ancient modern humans. The IAU also approved a coordinate system for mapping features on this uniquely shaped small world.
As of Sept. 9, the Lucy spacecraft was nearly 300 million miles (480 million km) from the Sun en route to its August 2027 encounter with its first Trojan asteroid called Eurybates. This places Lucy about three quarters of the way through the main asteroid belt. Since its encounter with Donaldjohanson, Lucy has been cruising without passing close to any other asteroids, and without requiring any trajectory correction maneuvers.
The team continues to carefully monitor the instruments and spacecraft as it travels farther from the Sun into a cooler environment.
Stay tuned at nasa.gov/lucy for more updates as Lucy continues its journey toward the never-before-explored Jupiter Trojan asteroids.
By Katherine Kretke
Southwest Research Institute
Explore More
5 min read Avatars for Astronaut Health to Fly on NASA’s Artemis II
Article
1 day ago
3 min read Weird Ways to Observe the Moon
Article
1 day ago
2 min read Hubble Surveys Cloudy Cluster
Article
4 days ago
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.