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Way up in space, the Sun isn’t just glowing, it’s throwing. Fast-moving particles slam into Earth’s upper atmosphere, triggering dramatic bursts of energy through a mysterious process called magnetic reconnection. These invisible explosions can unleash more power than the U.S. burns in a whole day.

Enter TRACERS: NASA’s Space Detective Duo

NASA’s TRACERS mission is sending twin satellites to investigate these wild space events. Their goal? To uncover how solar outbursts influence space weather, the invisible forces that affect satellites, power grids, and even radio signals down here on Earth.

NASA’s TRACERS mission is set to blast off in late July 2025 aboard a SpaceX Falcon 9 rocket from California’s Vandenberg Space Force Base.

After launch, the two spacecraft will orbit Earth to study how the solar wind, streams of charged particles from the Sun, interacts with Earth’s magnetic shield, known as the magnetosphere.

Earth’s magnetic field is gradually weakening

The Sun doesn’t just shine, it streams. Solar wind, a fierce mix of charged particles and tangled magnetic fields, races through space at over a million miles per hour, smacking into anything in its path.

Luckily, Earth has a guardian: the magnetosphere. Think of it as a floating cosmic shield, like a bar magnet spinning around in space, repelling most of the Sun’s fury. But when solar wind pressure builds, magnetic field lines can snap and whip particles away in explosive bursts; this is magnetic reconnection, one of space’s most powerful fireworks.

At Earth’s poles, the shield has entry points called polar cusps, funnel-shaped openings where particles pour in and crash into the atmosphere, painting the skies with auroras and, sometimes, chaos.

In May 2024, Earth got a taste of solar drama:

• The biggest geomagnetic storm in 20+ years
• Flights rerouted, power systems scrambled
• GPS-guided tractors lost track of the field

The two satellites of the TRACERS mission will fly “concurrently”, one after the other, in a relatively low orbit about 360 miles above Earth. They will travel at speeds exceeding 16,000 mph, equipped with a suite of instruments to measure various aspects of plasma and its interaction with Earth’s magnetosphere.

When the solar wind hits the magnetosphere, some energy waves …

The satellites will explore where Earth’s magnetic field descends to the ground at the North Polar Cusp. The satellites will be placed in a Sun-synchronous orbit, and they will always pass through Earth’s dayside polar cusp, studying thousands of reconnection events at these concentrated areas.

NASA’s twin TRACERS satellites aren’t just flying in circles; they’re dancing through Earth’s dayside polar cusp, a sweet spot where the planet’s magnetic field dips and solar particles stream in. By orbiting in sync with the Sun, TRACERS will repeatedly pass through this energetic gateway, capturing thousands of magnetic reconnection events in real time.

Why This Matters

This mission will stitch together a dynamic timeline of how magnetic reconnection evolves, not just across days, but from sunrise to starlight. It’s a leap beyond earlier snapshots, like the 2018 TRICE-2 mission, which launched short-term rockets over the Norwegian Sea and captured single moments.

“TRICE showed we could measure these effects,” said David Miles of the University of Iowa. “TRACERS shows we can track how they change.”

A method to study mini-magnetospheres

Previous missions could only grab a single snapshot of a space weather event, like trying to understand a thunderstorm from one lightning bolt. Too much was changing, too fast.

Enter NASA’s TRACERS satellites, flying in tandem like synchronized swimmers in space. Spaced just 10 seconds apart, they’ll capture multiple snapshots of the same stormy region, building a fluid, frame-by-frame view of how Earth’s magnetic shield reacts to the solar wind’s punch.

In one year, they’ll gather over 3,000 measurements, stitching together a time-lapse of how space weather unfolds around our planet. Scientists will finally be able to observe the magnetosphere as a dynamic system, rather than a static moment, improving predictions and paving the way for smarter safeguards against geomagnetic disruptions.

NASA’s new mission, TRACERS, isn’t going it alone; it’s joining a stellar squad of spacecraft across the solar system to better understand the Sun’s magnetic mood swings.

Early magnetic field around Earth was even stronger than previously believed

At the heart of it all is the Parker Solar Probe, which gets up close and personal with the Sun, tracking how magnetic reconnection heats and speeds up the solar wind, the very stuff TRACERS watches as it hits Earth.

Back at home, TRACERS taps into data from:

• EZIE, which studies electric currents on Earth’s nightside
• PUNCH, which keeps an eye on solar wind and its dance with Earth’s atmosphere

Together, this space fleet is building a clearer picture of how Earth’s magnetic shield opens up and lets solar particles stream in, sometimes lighting up the skies with auroras, and at other times interfering with satellites and power grids.

“TRACERS is a vital new piece of the puzzle,” says NASA’s Reinhard Friedel. “Combining forces across missions helps us predict and prepare for space weather impacts on our planet and our tech.”

The mission is led by David Miles from the University of Iowa, with instruments built by teams across Texas and California. From launchpads in Florida to space labs around the country, TRACERS is supported by NASA’s heliophysics experts and the VADR launch program.

On November 28, 1966, an American flight crossed the Antarctic Peninsula south of the southernmost tip of Chile. The plane was there to map the Antarctic landscape. Using a camera that may have been borrowed from the US Navy, the plan captured shots of the Wordie Ice Shelf, a once prominent part of the western Antarctic Peninsula located in Marguerite Bay. Once upon a time, this ice shelf – made up of multiple glaciers – covered an area of around 2,200 square kilometers (849 square miles), but as of the late 1980s, it started to retreat. By the early 2000s, it was almost completely gone, leaving behind a few small individual shelves.

An outcome of this loss was that the “plug” that held a lot of glacier ice broke off, contributing to sea level rise. Thankfully, the Wordie Ice Shelf was comparatively small, so this has only amounted to a rise on the scale of millimeters. However, there are more ice shelves in the Antarctic that could collapse due to climate change. Two in particular – Ronne and Ross – are thought to hold enough ice to produce a sea level rise of up to 5 meters (16 feet).

This will not be a remote incident either. It may feel like it is a long way away, but if these two ice shelves melt, then the sea level rise will be felt in places in the Northern Hemisphere too. This is where the newly discovered photo of the Wordie Ice Shelf can be so useful, representing a valuable first data point in the study of the ice shelf’s collapse over the subsequent years.

The team behind the research has used the image, alongside a vast archive of old aerial images and modern satellite observations, to show the collapse of an ice shelf as a constant process over a long period of time. This offers important insight that can help improve our understanding of these large icy structures and the mechanisms behind their demise. Moreover, it can be used to inform computer models to predict sea level rise, so we can prioritize how to adapt to climate change.

“We have identified several signs of incipient ice shelf collapse that we expect will be observed in other ice shelves, but perhaps more importantly, the dataset has given us a multitude of pinning points that can reveal how far advanced a collapse is,” lead author Mads Dømgaard, a postdoc from the Department of Geosciences and Natural Resource Management at the University of Copenhagen, said in a statement.

“It’s a completely new tool that we can use to do reality checks on ice shelves that are at risk of collapsing or already in the process of collapsing.”

The historical aerial photos were analyzed with a technique known as “structure-from-motion” photogrammetry, which allows scientists to reconstruct the ice’s thickness, its surface structure, extent, and its flow velocity all the way back to the 1960s.

What did this tell them? It was always assumed that the Wordie Ice Shelf collapsed due to a warmer atmosphere. At the same time, scientists believed that meltwater lakes had formed on the ice’s surface, which contributed to its disintegration. But analyzing the photos reveals that that does not seem to have been the case. Instead, the new research suggests that the main melting occurred under the ice where the sea and the shelf met.

“Our findings show that the primary driver of Wordie’s collapse is rising sea temperatures, which have generated the melting beneath the floating ice shelf,” Dømgaard said.

This research has already had a significant impact on our understanding of ice shelf collapse.

“The tentative conclusion from our findings is that ice shelf collapse may be slower than we thought. This means that the risk of a very rapid development of violent sea level rise from melting in Antarctica is slightly lower, based on knowledge from studies like this one,” study author Anders Anker Bjørk, Assistant Professor at the Department of Geosciences and Natural Resource Management, added.

But there is another side to this.

“It was already a supertanker that needed to be turned to stall the melting of ice in Antarctica, but our data shows a collapse process that is even more protracted than previously assumed,” said Bjørk. “And this longer process will make it harder to reverse the trend once it has started. This is an unambiguous signal to prioritize halting greenhouse gas emissions now rather than sometime in the future.”

The study is published in Nature Communications.