Last November, NASA and its European partners launched the Sentinel-6B satellite to improve hurricane forecasts, help protect infrastructure, and benefit commercial industries, including shipping. The satellite now is flying 30 seconds behind its predecessor, Sentinel-6 Michael Freilich. Both satellites are providing precise sea level height measurements during what oceanographers expect to be a historic El Niño, a naturally occurring oceanic phenomenon in which warmer-than-usual Pacific waters shift global weather patterns.

The two satellites make up the Copernicus Sentinel-6/Jason-CS (Continuity of Service) mission, the latest in a series of ocean-observing radar altimetry missions that have been monitoring Earth’s changing seas continuously since the early 1990s.

The data each satellite is collecting will not only allow scientists to better understand this year’s El Niño but will also help them create more accurate hurricane predictions.

“This El Niño was a late-bloomer,” said Josh Willis, Sentinel-6B’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “It didn’t kick off until the middle of the year and is just now reaching a strength similar to what we’ve seen in the satellite record during significant El Niños in 1997 and 2015. We expect it to be big, and it’s already having big impacts.”

El Niños generally scramble weather patterns tied to rainfall and storms, including hurricanes. They also redistribute heat in the ocean, which affects sea level. Normally, Earth’s warmest ocean waters sit along the equator in the western Pacific. During El Niño, weakened winds, which usually blow westward along the equator, result in heat spreading east toward South America. The change in ocean heat shifts hurricane activity from the Atlantic to the Pacific Ocean.

Predicting hurricane strength

On July 15, Sentinel-6B began delivering low-latency data to scientists that could be used for weather predictions. That data will take some time to work its way into the research models on which meteorologists and climate scientists rely, but when it does, those improved models could save lives.

Data from Sentinel-6 satellite missions feeds into hurricane tracking algorithms used by federal and state agencies. Those predictions can activate disaster response efforts, mobilizing resources ranging from sandbag placement to National Guard activation. They also can lead to evacuation orders that require quick but well-informed decisions about logistics at a local level. More severe events may require engaging larger organizations, such as the Federal Emergency Management Agency.

A tropical storm can take a week or more to become a hurricane and make its way to a coastline, but a hurricane can rapidly intensify in the 48 hours prior to landfall, leaving planners little time to prepare.

“Hurricanes have been known to speed up quickly at the last moment, so the window in which to decide what to do is short,” said Deirdre Byrne, an oceanographer and altimetry expert with the National Oceanic and Atmospheric Administration (NOAA). “The goal is to forecast how much and how rapidly intensification will happen so that officials can make the right calls.”

Byrne oversees one of the country’s most crucial hurricane forecasting algorithms, NOAA’s Satellite Ocean Heat Content Suite, which has been operating since 2012.

Each Sentinel-6 satellite measures ocean height, as well as the size of waves and marine wind speed, using a radar altimeter, which bounces thousands of radar pulses a second off the crests and troughs of waves. Ocean height varies from place to place and provides insight into the ocean’s heat content, since warm water expands. That, in turn, helps forecast how fast hurricanes will grow.

The satellites each carry a second instrument, called the Global Navigation Satellite System – Radio Occultation (GNSS-RO), which measures atmospheric properties, such as humidity, pressure, and temperature.

Among the measurements Sentinel-6 is gathering, Byrne is most anticipating the ocean height data, which she plans to begin incorporating into the current Satellite Ocean Heat Content Suite algorithm by the end of the year.

“In terms of data quality, the Sentinel-6 missions are unparalleled,” Byrne said.

Together, the missions are also extending a precise dataset deep into its fourth decade. This record of sea level observations traces back to the TOPEX/Poseidon mission, which launched in 1992, and continues through to the present day with Sentinel-6 Michael Freilich. Sentinel-6B will take over for its predecessor as the reference satellite for global sea level measurements later this year.

“The key is consistency, measuring the same way, every time,” said Severine Fournier, Sentinel-6B deputy project scientist, JPL. “That’s what lets us predict hurricanes, and, in turn, protect coastal communities and infrastructure.”

More about Sentinel-6B

Sentinel-6 Michael Freilich, named after a former director of NASA’s Earth Science Division, is one of two satellites that compose the Copernicus Sentinel-6/Jason-CS mission.

Sentinel-6/Jason-CS, a part of the European Union’s Earth observation program called Copernicus, was jointly developed by ESA (European Space Agency), EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), NASA, and NOAA, with funding support from the European Commission and technical support on performance from the French space agency CNES (Centre National d’Études Spatiales). Spacecraft monitoring and control, as well as the processing of all the altimeter science data, is carried out by EUMETSAT on behalf of the European Union’s Copernicus Programme, with the support of all partner agencies.

NASA JPL, a division of Caltech in Pasadena, contributed three science instruments for each Sentinel-6 satellite: the Advanced Microwave Radiometer, the GNSS-RO, and the Laser Retroreflector Array. NASA also contributed launch services, ground systems supporting operation of the agency’s science instruments, the science data processors for two of these instruments, and support for the United States members of the international Ocean Surface Topography Science Team.

For more about Sentinel-6B, visit:

https://science.nasa.gov/mission/sentinel-6B

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Media Contacts

Andrew Good / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433 / 626-379-6874
andrew.c.good@jpl.nasa.gov / andrew.wang@jpl.nasa.gov

2026-060

NASA’s Perseverance Mars rover has uncovered evidence that a 245-foot-thick (75-meter-thick) stack of ancient rock on the rim of Jezero Crater was built by repeated asteroid impacts. Referred to as the “Broom Point member” by the rover’s science team, this sequence of layered bedrock is likely more than 3.9 billion years old, making it among the oldest terrain ever examined by a Mars rover.  

Released Wednesday in the Journal of Geophysical Research: Planets, the findings offer a window into one of the most tumultuous chapters in the history of the solar system.  

“Since leaving Jezero, Perseverance has been exploring a brand-new frontier, both geographically and geologically — a chapter of Martian time that predates the crater itself,” said Ken Farley, Perseverance deputy project scientist at Caltech in Pasadena, California. “On Earth, our earliest geologic history has been fundamentally broken up, deformed, and erased by plate tectonics. Because Mars lacks plate tectonics to recycle its crust, this ancient record remains intact, giving us a rare glimpse into a geological time period that doesn’t exist on our own planet.” 

Reading between layers 

After ascending the western rim of Jezero Crater in late 2024, Perseverance began examining surrounding locations with its science instruments. Their data at Broom Point revealed six distinct rock types, including breccias — rocks composed of angular fragments — alternating with layers of fine-grained, pulverized rock dust. Rock fragments within the breccias are pocked with gas-bubble cavities, indicating they were once molten. 

The presence of tiny, dark, glassy beads within the layers offered an important clue about how these rocks formed. While volcanoes can produce similar glassy droplets, they rarely occur in such high abundance, pointing to asteroid impacts, instead, as the primary architect. In fact, the largest beads rival those flung out by the dinosaur-killing Chicxulub asteroid’s impact on Earth. 

The repetition of these distinct rock types multiple times throughout this thick sequence of rock indicates that high-energy impact events happened again and again across this region of early Mars. 

“The different rock layers are a record of variable-sized impacts occurring at different distances from where this rock sequence was accumulating,” said Alex Jones, a Ph.D. student in planetary geology at Imperial College London and lead author of the paper. “Some large impacts took place very far away, some small impacts nearby. Their debris all ended up landing here, constructing this thick section of rock.”  

How these layers formed may suggest an interaction with water or ice. Several of the layers look like they may have been formed by fast, ground-hugging debris flows. On Earth, these powerful, fluidlike surges can occur when molten rock hits water or ice that instantly flashes into steam.  

Cosmic one-two punch 

Some of Broom Point’s layers tilt at angles exceeding 80 degrees — nearly vertical — which is far too steep to be caused by the impact that created Jezero Crater.  

Instead, scientists suspect a cosmic “one-two punch” shaped this landscape long ago. First, a colossal asteroid impact created the 1,200-mile-wide (1,900-kilometer-wide) Isidis Basin, one of the largest impact basins on Mars, upending and tilting the once-flat rock layers. Later, a second asteroid likely struck, forming Jezero Crater, which measures 28 miles (45 kilometers) across. This second impact fractured and uplifted the already-tilted rocks into the dramatic formations the rover sees today.  

To pin down exactly when these events took place, the Perseverance team collected two core samples, dubbed “Bell Island” and “Main River.” If a future mission were to return them to Earth, laboratory dating could determine when and how often impacts were occurring on early Mars — and, by extension, the infant Earth, whose own early impact record has been erased by billions of years of plate tectonics. 

“During this violent era, it wasn’t rain or snow falling from the sky, but an almost constant barrage of molten rock droplets and pulverized dust kicked up by asteroid impacts,” said Jones. “If we can pin down the ages of these layers, it would be like reading a cosmic weather report from 4 billion years ago.” 

More about Perseverance 

NASA’s Jet Propulsion Laboratory in Southern California, which is managed for the agency by Caltech, built and manages operations of the Perseverance rover on behalf of the agency’s Science Mission Directorate in Washington, as part of NASA’s Mars Exploration Program portfolio. Arizona State University leads the operations of the rover’s Mastcam-Z instrument, working in collaboration with Malin Space Science Systems in San Diego, on the design, fabrication, testing, and operation of the cameras. SuperCam is led by Los Alamos National Laboratory in New Mexico, where the instrument’s Body Unit was developed. The rover’s SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) instrument was built at NASA JPL, and its WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera was built at Malin Space Science Systems.

For more information on NASA’s Perseverance, visit:

https://science.nasa.gov/mission/mars-2020-perseverance

News Media Contacts

DC Agle 
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov  

Karen Fox / Alana Johnson
NASA Headquarters, Washington
240-285-5155 / 202-672-4780
karen.c.fox@nasa.gov / alana.r.johnson@nasa.gov

2026-045

Celebrating its 90th anniversary this year, NASA’s Jet Propulsion Laboratory invites the public to its campus at the base of the San Gabriel Mountains in Southern California for an open-house event, Explore JPL. On Oct. 10 and 11, from 9:30 a.m. to 4 p.m. PDT, visitors will get the chance to visit JPL’s most iconic facilities and explore four thematic areas: Missions That Changed the World, Moon to Mars, In Flight, and Makerspace. 

Tickets are free but very limited and have gone quickly for past Explore JPL events. They will be available on the Explore JPL webpage at 9 a.m. PDT Saturday, Aug. 29, and will be distributed on a first-come, first-served basis, with a maximum of five tickets per requestor. Orders for more than five tickets may be subject to cancellation. Tickets will be provided for specific time slots and must be reserved for specific names. Attendees will not be admitted to JPL before the designated time printed on their ticket. 

A division of Caltech in Pasadena, California, JPL traces its origins to rocket-propulsion development in 1936. By 1958, the lab had built and helped launch America’s first satellite, Explorer 1. That same year, Congress established NASA, and JPL became a part of the agency. Since then, JPL has managed such historic missions as Voyager, Galileo, Cassini, the Mars Exploration Rover program, the Perseverance Mars rover, Europa Clipper, and many more.

Among other highlights, Explore JPL guests will get to: 

• Visit JPL’s legendary Space Flight Operations Facility, a National Historic Landmark where engineers send commands and receive data from spacecraft billions of miles away. 

• Discover the Spacecraft Assembly Facility and JPL Machine Shop, where precision spacecraft components are crafted. 

• See the latest cutting-edge innovations in robotics research, from autonomous lunar rovers to search-and-rescue robots. 

• Get up close with full-scale models of the Perseverance Mars rover, Voyager, and Galileo. 

• Step inside the Microdevices Laboratory to see how miniature technologies developed there are shaping the future of space exploration and Earth science. 

To attend Explore JPL, visitors must have their tickets in hand and anyone age 18 or over must show government-issued identification. Tickets are not transferable and cannot be sold. Children under age 2 do not require a ticket, but experiences at the event are not intended for very young guests. 

Visitors may not bring these items to JPL: weapons or explosives of any kind, incendiary devices, glass containers, alcohol, cannabis or illegal drugs, pets (except certified service animals), banners or signs, flags, boom boxes, air horns, musical instruments, and professional camera equipment with detachable telephoto lenses. Use of laser pointers or whistles is not allowed. No bags, backpacks, or hard-sided coolers are permitted, either, except small purses and diaper bags. Drones are not allowed to fly over JPL under any circumstances. Skates, skateboards, scooters, Segways, and bicycles are not permitted inside the event, as the venues are crowded with pedestrians. 

Vehicles entering JPL property are subject to inspection. Parking is free. 

Follow JPL on Facebook, X, and Instagram. 

To get a virtual tour of JPL, visit:

https://www. jpl.nasa.gov/virtual-tour/

Media Contact 
JPL-media@jpl.nasa.gov