NASA’s New Horizons spacecraft carried out an unprecedented deep-space star navigation test while 438 million miles from Earth. Using its long-range camera in April 2020, it captured images of Proxima Centauri and Wolf 359, which appeared slightly shifted in the sky compared to Earth’s view – a striking demonstration of stellar parallax. It was the first-ever demonstration of deep-space stellar navigation. By comparing these images to Earth-based observations and a 3D star chart, scientists calculated New Horizons’ position to within about 4.1 million miles, only about 26 inches across the United States.
Stellar Parallax Test
According to the paper describing the results, accepted for publication in The Astronomical Journal, New Horizons’ camera imaged Proxima Centauri (4.2 light-years away) and Wolf 359 (7.86 light-years) on April 23, 2020. From the spacecraft’s distant vantage point, the two stars appear in different positions than seen from Earth – the essence of stellar parallax. By comparing those images with Earth-based data and a three-dimensional map of nearby stars, the team worked out the probe’s location to within about 4.1 million miles.
As lead author Tod Lauer explained, “Taking simultaneous Earth/Spacecraft images we hoped would make the concept of stellar parallaxes instantly and vividly clear”. He added, “It’s one thing to know something, but another to say ‘Hey, look! This really works!’”.
New Horizons and Future Missions
New Horizons, the fifth spacecraft to leave Earth and reach interstellar space, flew past Pluto and its moon Charon in 2015, sending home the first close-up images of those distant icy worlds. Now on an extended mission, the probe is studying the heliosphere.
New Horizons’ principal investigator Alan Stern called the parallax test “a pioneering interstellar navigation demonstration” that shows a spacecraft can use onboard cameras “to find its way among the stars”, in a statement. He also noted it “could be highly useful for future deep space missions in the far reaches of the Solar System and in interstellar space”
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![Scientists Found a Continent-Sized Geological Structure Hiding Beneath Antarctica
The East Antarctic Ice Sheet is almost unfathomably huge. Covering about 75% of the entire frigid continent (nearly everything on its side of the Transantarctic Mountains), the sheet covers about 3.9 million square miles (10.2 million square kilometers) and extends down 1.4 miles (2.2 km), on average, before coming into contact with Earth’s surface. At its deepest, the ice plunges down over 3 miles (4.9 km). For decades, scientists assumed that this literally continent-sized block of ice rested on an expansive and stable chunk of Earth’s crust known as a craton. A team of researchers has now complicated that picture—mapping a vast, interconnected geological structure that fans out from a troubling “tectonic deformation.” Beneath this ice sheet, thinner and more geologically recent slices of crusty lithosphere fan out into hidden valleys called “pull-apart basins.” These basins—30 elongated wedge-shaped valleys in total—constitute an entirely new, continental-scale geological region underneath Antarctica, in fact, one which the researchers have named the East Antarctic Fan-Shaped Basin Province (EAFBP). But it’s how they likely formed that has now caught researchers’ attention.
To put it bluntly, it turns out that about 90% of the planet’s fresh water ice may not be on solid ground. Geologist John Goodge called the team’s findings “provocative” in an independent commentary on the new study, published Thursday in the journal Nature Geoscience.
“East Antarctica is typically considered from seismic tomography and geodetics to be ancient and generally stable,” according to Goodge, who studies continental tectonics with the nonprofit Planetary Science Institute. “[But] something else is going on at depth.” Continental divides Goodge speculates that this seemingly “coherent pull-apart system,” as presented in the new study, might help explain a variety of mysterious heat and water flows beneath this ice sheet’s surface, like that enormous subglacial lake identified in 2016 or some of the hundreds more like it.
The study’s authors, led by geophysicist Egidio Armadillo at the University of Genoa in Italy, agreed: “Because these basins underlie about half of the East Antarctic Ice Sheet, they are likely to heavily influence both ice-flow and landscape evolution,” the researchers wrote in their study, also published Thursday in Nature Geoscience. Armadillo’s team, coordinating across Europe and the U.K., developed their new understanding of Antarctica’s hidden bedrock via an exhaustive set of sensory data. Gravitational and magnetic anomalies were mapped via low-altitude airborne surveys. Ground surface features were mapped with seismic tools, using sound waves that vibrate through the ice and ping back information about subglacial landscapes in 3D. The grey, magenta, and cyan lines represent the apparent new fault lines discovered. Credit: Nature Geoscience All of this data—the fruits of “multi-national efforts to image within and below the ice sheet,” as Goodge put it—had already revealed that regions of the continent were “undergoing more rapid movement and ice-mass loss than previously recognized.” Armadillo’s team merely helped to explain why.
The mechanism Armadillo and his colleagues proposed for the formation of these fan-shaped basins is called “distributed rotational extension.” It involves points called Euler poles around which tectonic plates pivot or rotate rather than smash into each other or pull apart. The result is a bit like decks of cards being spread out on a table, thinning out the stack of Earth’s crust as it moves. An icy situation Goodge took pains to spell out the basins’ implications for melting Antarctic ice due to climate change and the risk of rising global sea levels.
The mere existence of these basins, he wrote, “could introduce widespread, systemic instability to the East Antarctic Ice Sheet” via thinner layers of Earth’s crust and more heat flow from below. On top of that, a series of fault-line “troughs” documented between the basins appear “tailor-made to promote outward flow of ice streams from the interior” into the world’s oceans, he said. That said, the team’s findings are unlikely to end this debate. As Goodge noted, Antarctica is “the last continental frontier of scientific exploration.” It’s still a very mysterious place, one that’s challenging to study given its inhospitable temperatures and extreme geography. Its “cryptic subglacial geology” might stay that way for a while. #Scientists #ContinentSized #Geological #Structure #Hiding #Beneath #AntarcticaAntarctica,Geology,mapping,Plate tectonics Scientists Found a Continent-Sized Geological Structure Hiding Beneath Antarctica
The East Antarctic Ice Sheet is almost unfathomably huge. Covering about 75% of the entire frigid continent (nearly everything on its side of the Transantarctic Mountains), the sheet covers about 3.9 million square miles (10.2 million square kilometers) and extends down 1.4 miles (2.2 km), on average, before coming into contact with Earth’s surface. At its deepest, the ice plunges down over 3 miles (4.9 km). For decades, scientists assumed that this literally continent-sized block of ice rested on an expansive and stable chunk of Earth’s crust known as a craton. A team of researchers has now complicated that picture—mapping a vast, interconnected geological structure that fans out from a troubling “tectonic deformation.” Beneath this ice sheet, thinner and more geologically recent slices of crusty lithosphere fan out into hidden valleys called “pull-apart basins.” These basins—30 elongated wedge-shaped valleys in total—constitute an entirely new, continental-scale geological region underneath Antarctica, in fact, one which the researchers have named the East Antarctic Fan-Shaped Basin Province (EAFBP). But it’s how they likely formed that has now caught researchers’ attention.
To put it bluntly, it turns out that about 90% of the planet’s fresh water ice may not be on solid ground. Geologist John Goodge called the team’s findings “provocative” in an independent commentary on the new study, published Thursday in the journal Nature Geoscience.
“East Antarctica is typically considered from seismic tomography and geodetics to be ancient and generally stable,” according to Goodge, who studies continental tectonics with the nonprofit Planetary Science Institute. “[But] something else is going on at depth.” Continental divides Goodge speculates that this seemingly “coherent pull-apart system,” as presented in the new study, might help explain a variety of mysterious heat and water flows beneath this ice sheet’s surface, like that enormous subglacial lake identified in 2016 or some of the hundreds more like it.
The study’s authors, led by geophysicist Egidio Armadillo at the University of Genoa in Italy, agreed: “Because these basins underlie about half of the East Antarctic Ice Sheet, they are likely to heavily influence both ice-flow and landscape evolution,” the researchers wrote in their study, also published Thursday in Nature Geoscience. Armadillo’s team, coordinating across Europe and the U.K., developed their new understanding of Antarctica’s hidden bedrock via an exhaustive set of sensory data. Gravitational and magnetic anomalies were mapped via low-altitude airborne surveys. Ground surface features were mapped with seismic tools, using sound waves that vibrate through the ice and ping back information about subglacial landscapes in 3D. The grey, magenta, and cyan lines represent the apparent new fault lines discovered. Credit: Nature Geoscience All of this data—the fruits of “multi-national efforts to image within and below the ice sheet,” as Goodge put it—had already revealed that regions of the continent were “undergoing more rapid movement and ice-mass loss than previously recognized.” Armadillo’s team merely helped to explain why.
The mechanism Armadillo and his colleagues proposed for the formation of these fan-shaped basins is called “distributed rotational extension.” It involves points called Euler poles around which tectonic plates pivot or rotate rather than smash into each other or pull apart. The result is a bit like decks of cards being spread out on a table, thinning out the stack of Earth’s crust as it moves. An icy situation Goodge took pains to spell out the basins’ implications for melting Antarctic ice due to climate change and the risk of rising global sea levels.
The mere existence of these basins, he wrote, “could introduce widespread, systemic instability to the East Antarctic Ice Sheet” via thinner layers of Earth’s crust and more heat flow from below. On top of that, a series of fault-line “troughs” documented between the basins appear “tailor-made to promote outward flow of ice streams from the interior” into the world’s oceans, he said. That said, the team’s findings are unlikely to end this debate. As Goodge noted, Antarctica is “the last continental frontier of scientific exploration.” It’s still a very mysterious place, one that’s challenging to study given its inhospitable temperatures and extreme geography. Its “cryptic subglacial geology” might stay that way for a while. #Scientists #ContinentSized #Geological #Structure #Hiding #Beneath #AntarcticaAntarctica,Geology,mapping,Plate tectonics](https://gizmodo.com/app/uploads/2026/06/East-Antarctic-Fan-shaped-Basin-Province.jpeg)
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