Scientists use satellites to mimic a total solar eclipse in space
Two European satellites have successfully manufactured artificial solar eclipses by maintaining a precise formation in space. This innovative technique offers scientists extended periods of totality on demand.
The European Space Agency unveiled images from these eclipses at the Paris Air Show on Monday. The pair of satellites, launched in late 2023, have been creating simulated solar eclipses since March, while orbiting thousands of miles above the Earth.
The satellites fly 492 feet (150 meters) apart. One satellite blocks the sun, mimicking the moon's role in a natural solar eclipse. The other satellite then focuses its telescope on the corona, the sun's outer atmosphere, which appears as a halo of light.
It's an intricate, prolonged dance requiring extreme precision by the cube-shaped spacecraft, less than 5 feet (1.5 meters) in size. Their flying accuracy needs to be within a mere millimeter, the thickness of a fingernail. This meticulous positioning is achieved autonomously through GPS navigation, star trackers, lasers and radio links.
Dubbed Proba-3, the $210 million mission has generated 10 successful solar eclipses so far during the ongoing checkout phase. The longest eclipse lasted five hours, said the Royal Observatory of Belgium's Andrei Zhukov, the lead scientist for the orbiting corona-observing telescope. He and his team are aiming for a wondrous six hours of totality per eclipse once scientific observations begin.
Scientists already are thrilled by the preliminary results that show the corona without the need for any special image processing, said Zhukov.
"We almost couldn't believe our eyes,' Zhukov said in an email. 'This was the first try, and it worked. It was so incredible.'
Zhukov anticipates an average of two solar eclipses per week being produced for a total of nearly 200 during the two-year mission, yielding more than 1,000 hours of totality. That will be a scientific bonanza since full solar eclipses produce just a few minutes of totality when the moon lines up perfectly between Earth and the sun — on average just once every 18 months.
The sun continues to mystify scientists, especially its corona, which is hotter than the solar surface. Coronal mass ejections result in billions of tons of plasma and magnetic fields being hurled out into space. Geomagnetic storms can result, disrupting power and communication while lighting up the night sky with auroras in unexpected locales.
While previous satellites have generated imitation solar eclipses — including the European Space Agency and NASA's Solar Orbiter and Soho observatory — the sun-blocking disk was always on the same spacecraft as the corona-observing telescope. What makes this mission unique, Zhukov said, is that the sun-shrouding disk and telescope are on two different satellites and therefore far apart.
The distance between these two satellites will give scientists a better look at the part of the corona closest to the limb of the sun.
"We are extremely satisfied by the quality of these images, and again this is really thanks to formation flying' with unprecedented accuracy, ESA's mission manager Damien Galano said from the Paris Air Show.
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
an hour ago
- Yahoo
James Webb Peers Into Mysterious Haze Covering Pluto
Astronomers using the James Webb Space Telescope have peered into a mysterious blue haze cloaking the surface of Pluto — and discovered that it's controlling the dwarf planet's climate and atmosphere. The findings, reported in a new study published in the journal Nature Astronomy, also hint that other worlds, including our own, may have a hazy history as well, potentially reshaping our understanding of how the Earth came to possess its current climate. "This is unique in the solar system," lead author Tanguy Bertrand, an astronomer at the Paris Observatory in France, told Live Science. "It's a new kind of climate, let's say." When NASA's New Horizons mission flew by Pluto in 2015, the space probe revealed that the dwarf planet was far from a "dead" world, instead possessing a complex geography defined by mountains, glaciers, ice sheets, and frozen dunes. Regions even differed in the type of ice they comprised: some were dominated by methane, others nitrogen, and all of it undergirded by a "bedrock" of water ice. In the most blatant violation of Pluto's former reputation as an inert hunk, the aptly-named "volatile" ices on its surface regularly redistributed themselves according to seasonal patterns. One of the most peculiar finds, however, was that Pluto appeared to be leaking copious amounts of its already thin atmosphere into space, noted. Stranger still, some of these discarded gas molecules were being sucked up directly by its outsized moon, Charon, something that's yet to be witnessed elsewhere in the solar system. To explain this bizarre behavior, a 2017 paper led by Xi Zhang, a planetary scientist at the University of California, Santa Cruz who also coauthored this latest study, predicted that Pluto's atmosphere was covered with a cooling haze made of nitrogen and methane. As Live Science explains, the haze intervened by absorbing what little solar radiation reached it during the day — on average, Pluto orbits at a distance 39 times farther away than the Earth is from the Sun — and releasing it back into space at night in the form of infrared energy. At least, that was the theory. Because of how closely Charon, the huge moon, orbited Pluto, the pair's temperature readings were jumbled together. Resolving one from the other was impossible. "Basically, we couldn't know what part of the signal is due to Charon and what part is due to Pluto's haze," Bertrand told Live Science. Enter the James Webb Space Telescope. According to the 2017 study, if the haze behaved as predicted, Pluto should emit strong radiation in the mid-infrared spectrum. Webb, with its state-of-the-art Mid-Infrared Instrument (MIRI), was able to distinguish between Pluto's signals and those of its moon, confirming that the dwarf planet's haze was producing the predicted light emissions. "In planetary science, it's not common to have a hypothesis confirmed so quickly, within just a few years," Zhang said in a statement about the work. "So we feel pretty lucky and very excited." According to Zhang, other worlds in the Solar System, including Neptune's moon Triton and Saturn's moon Titan, possess haze-rich atmospheres similar to Pluto's — "so we need to rethink their roles, too," he said. Even Earth may be due for some serious climate introspection. "Before oxygen built up in Earth's atmosphere, about 2.4 billion years ago, life already existed," Zhang explained. "But back then, Earth's atmosphere was totally different — no oxygen, mostly nitrogen, and a lot of hydrocarbon chemistry." "So by studying Pluto's haze and chemistry," he added, "we might get new insights into the conditions that made early Earth habitable." More on James Webb discoveries: NASA's James Webb Telescope Just Found Frozen Water Around Another Star
Yahoo
an hour ago
- Yahoo
Mysterious fast radio bursts help astronomers pinpoint cosmic ‘missing' matter
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Astronomers have used mysterious fast radio bursts, or millisecond-long bright flashes of radio waves from space, to help them track down some of the missing matter in the universe. Dark matter and dark energy make up most of the universe. Dark matter is an enigmatic substance that shapes the cosmos, while dark energy is a force that accelerates the expansion rate of the universe, according to NASA. Both are impossible to directly observe but can be detected due to their gravitational effects. But the rest of the universe is made of cosmic baryons, or ordinary matter, which can be found in tiny particles called protons and neutrons. 'If you add up all the stars and planets and cold gas that you see with your telescopes, it only amounts to less than 10% of ordinary matter in the universe,' said Liam Connor, assistant professor of astronomy at Harvard University. While astronomers thought most of the universe's ordinary matter was floating in the spaces between galaxies, called the intergalactic medium, or within the extended halos of galaxies — vast, spherical regions including stars and hot gas — they couldn't measure this foglike matter. That's because ordinary matter emits light at different wavelengths, but much of it is so diffuse that it's like trying to spot fog, astronomers say. The inability to detect roughly half of the cosmos' ordinary matter led to a decades-long cosmology struggle called the missing baryon problem. Now, Connor and his colleagues have directly observed the missing matter by using the flashing of fast radio bursts to essentially map out what couldn't be seen before. They reported their findings in a new study published Monday in the journal Nature Astronomy. 'The FRBs shine through the fog of the intergalactic medium, and by precisely measuring how the light slows down, we can weigh that fog, even when it's too faint to see,' Connor, the paper's lead author, said. Much of the work for the study took place while Connor was a research assistant at the California Institute of Technology. Down the road, astronomers believe they can use fast radio bursts to help illuminate the otherwise invisible structure of the universe. More than a thousand fast radio bursts, or FRBs, have been detected since their discovery in 2007. Only about 100 have been traced back to galaxies, according to the study authors. Astronomers are still unsure of the exact causes behind the bursts, but finding more of them could reveal their murky origins. To illuminate the missing matter, the new analysis relied on a mixture of previously observed fast radio bursts, as well as bright flashes that had never been observed until the research was underway. The 69 fast radio bursts examined in the study exist at distances ranging from 11.74 million to nearly 9.1 billion light-years from Earth. The farthest, named FRB 20230521B, was discovered during the research and is the current record holder for the most distant fast radio burst ever observed. The study team used the Deep Synoptic Array, a network of 110 radio telescopes, to find and identify 39 of the fast radio bursts in the study. The telescope array, designed to trace fast radio bursts back to their origin points, is located near Bishop, California, at Caltech's Owens Valley Radio Observatory. The W. M. Keck Observatory in Hawaii and Palomar Observatory near San Diego helped measure the distances between the fast radio bursts and Earth. And the other 30 fast radio bursts were found by the Australian Square Kilometre Array Pathfinder and other telescopes around the world. When radio waves travel as fast radio bursts toward Earth, their light can be measured in different wavelengths that spread out. How much the light spreads out is dependent on how much matter is in its path. The team was able to measure how much each fast radio burst signal slowed down as it passed through space before reaching Earth, illuminating the gas it encountered along the way. The speed of fast radio bursts can be affected by what they travel through, meaning different wavelengths of light arrive at different times. While long, red wavelengths travel more slowly to reach Earth, shorter, bluer wavelengths arrive more quickly. Each wavelength allowed astronomers to measure the invisible matter. The short pulses of fast radio bursts are crucial for this measurement because they act like flashing cosmic beacons, Connor said. 'We can measure very precisely how much the radio pulse is slowed down at different wavelengths (it's called plasma dispersion), and this effectively counts up all the baryons,' Connor said. 'For a star that shines continuously or a source that is not in the radio, we can not measure this 'dispersion' effect. It must be impulsive, short, and at radio wavelengths.' The team was able to use the dispersion of light to map and measure matter along the pathway of the fast radio bursts. 'It's like we're seeing the shadow of all the baryons, with FRBs as the backlight,' said study coauthor Vikram Ravi, an assistant professor of astronomy at Caltech, in a statement. 'If you see a person in front of you, you can find out a lot about them. But if you just see their shadow, you still know that they're there and roughly how big they are.' After mapping out all the fast radio bursts and the matter they passed through and illuminated, the team determined that 76% of cosmic matter exists as hot, low-density gas in the space between galaxies. Another 15% can be found in galactic halos, while the remainder is located within galaxies themselves as stars, planets or cold gas. The observation-based findings align with prior predictions made using simulations, according to the study authors. William H. Kinney, professor of physics at the University at Buffalo's College of Arts and Sciences, agreed. 'So the upshot is that they came up with a new way of finding the baryons we knew had to be there, but whether they were really in the (intergalactic medium) instead of in halos was still something of an open question,' said Kinney, who was not involved in the research. 'The decades-old 'missing baryon problem' was never about whether the matter existed,' Connor said. 'It was always: Where is it? Now, thanks to FRBs, we know: Three-quarters of it is floating between galaxies in the cosmic web.' Understanding the distribution of ordinary matter can help researchers understand how galaxies grow and evolve. 'Baryons are pulled into galaxies by gravity, but supermassive black holes and exploding stars can blow them back out — like a cosmic thermostat cooling things down if the temperature gets too high,' Connor said. 'Our results show this feedback must be efficient, blasting gas out of galaxies and into the (intergalactic medium).' Fast radio bursts also may be able to help map the cosmic web in detail, Ravi said. This structure, largely made of dark matter, serves as the backbone of the universe, according to NASA. Caltech is currently planning to build another radio telescope in the Nevada desert, which could build upon the findings from the new study by finding and tracing up to 10,000 fast radio bursts per year, Connor said. 'It's a triumph of modern astronomy,' Ravi said.'We're beginning to see the Universe's structure and composition in a whole new light, thanks to FRBs. These brief flashes allow us to trace the otherwise invisible matter that fills the vast spaces between galaxies.'
Yahoo
an hour ago
- Yahoo
A look at the first artificial solar eclipses created by two European satellites
CAPE CANAVERAL, Fla. (AP) — A pair of European satellites have created the first artificial solar eclipses by flying in precise and fancy formation, providing hours of on-demand totality for scientists. The European Space Agency released the eclipse pictures at the Paris Air Show on Monday. Launched late last year, the orbiting duo have churned out simulated solar eclipses since March while zooming tens of thousands of miles (kilometers) above Earth. Flying 492 feet (150 meters) apart, one satellite blocks the sun like the moon does during a natural total solar eclipse as the other aims its telescope at the corona, the sun's outer atmosphere that forms a crown or halo of light. It's an intricate, prolonged dance requiring extreme precision by the cube-shaped spacecraft, less than 5 feet (1.5 meters) in size. Their flying accuracy needs to be within a mere millimeter, the thickness of a fingernail. This meticulous positioning is achieved autonomously through GPS navigation, star trackers, lasers and radio links. Dubbed Proba-3, the $210 million mission has generated 10 successful solar eclipses so far during the ongoing checkout phase. The longest eclipse lasted five hours, said the Royal Observatory of Belgium's Andrei Zhukov, the lead scientist for the orbiting corona-observing telescope. He and his team are aiming for a wondrous six hours of totality per eclipse once scientific observations begin in July. Scientists already are thrilled by the preliminary results that show the corona without the need for any special image processing, said Zhukov. "We almost couldn't believe our eyes,' Zhukov said in an email. 'This was the first try, and it worked. It was so incredible.' Zhukov anticipates an average of two solar eclipses per week being produced for a total of nearly 200 during the two-year mission, yielding more than 1,000 hours of totality. That will be a scientific bonanza since full solar eclipses produce just a few minutes of totality when the moon lines up perfectly between Earth and the sun — on average just once every 18 months. The sun continues to mystify scientists, especially its corona, which is hotter than the solar surface. Coronal mass ejections result in billions of tons of plasma and magnetic fields being hurled out into space. Geomagnetic storms can result, disrupting power and communication while lighting up the night sky with auroras in unexpected locales. While previous satellites have generated imitation solar eclipses — including the European Space Agency and NASA's Solar Orbiter and Soho observatory — the sun-blocking disk was always on the same spacecraft as the corona-observing telescope. What makes this mission unique, Zhukov said, is that the sun-shrouding disk and telescope are on two different satellites and therefore far apart. The distance between these two satellites will give scientists a better look at the part of the corona closest to the limb of the sun. "We are extremely satisfied by the quality of these images, and again this is really thanks to formation flying' with unprecedented accuracy, ESA's mission manager Damien Galano said from the Paris Air Show. ___ AP journalist John Leicester contributed to this report from Paris. ___ The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.