Latest news with #solarCorona
Yahoo
18-06-2025
- Science
- Yahoo
First artificial solar eclipse from space captured by ESA Proba-3 mission
A satellite duo orbiting our planet has just captured the very first images of an artificial solar eclipse from space, providing us with a spectacular view of the Sun's corona — a view only rarely available to us here on Earth. Total solar eclipses are amazing to behold. They spark awe and wonder in those fortunate enough to witness the event. Also, the brief moments of totality give us a chance to see and study parts of the Sun that are nearly impossible to observe at any other time. The April 8 total solar eclipse, imaged from Dallas, Texas, during 'totality', when the Moon completely blocked the Sun. While a few red-tinged prominances are visible along the edge of the Moon, the primary feature we see is the solar corona, which is shaped and sculpted by the Sun's powerful magnetic fields. (NASA/Keegan Barber) The solar corona is the Sun's atmosphere. It is the source of the solar wind, which constantly flows past our planet and causes auroras to shine near the north and south poles. It also holds one of the biggest mysteries of our solar system, as it reaches temperatures of about 1 million degrees Celsius, while the surface of the Sun (the photosphere) is only around 5,500°C. There have been clues over the years, but overall, scientists are still trying to find out exactly why the corona is so much hotter than the photosphere. The main reason for this is that studying the corona is challenging. We can see it during a total solar eclipse, but those are few and far in-between. And even when one does occur, the time they have to observe it — right at totality — only lasts for a few minutes each time. Jets have been able to extend this time a bit, as they fly straight down the path of totality, but the shadow of the Moon moves too quickly to get a sustained look. Special cameras known as coronagraphs give us longer observations of the corona. Two flying in space right now, one on the NASA/ESA Solar and Heliospheric Observatory (SOHO) and the other on the GOES-19 weather satellite, have a small disk at the end of an arm positioned in front of the camera lens to cover the Sun. Two composite views of the Sun from SOHO and the Solar Dynamics Observatory show the outer parts of the solar corona. As the innermost part of each image reveals, there is a lot of space between the inner edge of SOHO's coronagraph view and the surface of the Sun, which means we do not get a consistent look at the inner corona. (NASA SDO/NASA-ESA SOHO/Scott Sutherland) With that disk in place, the sensitive camera can then pick up the much fainter activity going on around the Sun. However, when scientists fly one of these instruments, they have to account for the entire range of distance the satellite will be from the Sun, thus the disk has to give a lot of leeway, to prevent the Sun from peaking around the edge of the coronagraph and burning out the optics. Thus, these coronagraphs can never give us as good a view of the corona as we see during a total solar eclipse, where we can even view the very lowest layers of the Sun's atmosphere. The European Space Agency's Proba-3 mission solves that problem, though. The two satellites that are part of the mission — the Coronagraph and the Occulter — fly in precise formation, orbiting around the Earth. Each time they come around on the Sun-ward side of the planet, they line up perfectly, at just the right distance, that the Occulter perfectly covers up the Sun's disk, just like the Moon does during a total solar eclipse. Proba-3's Coronagraph and Occulter fly in tandom as they loop around the sunward side of Earth, with the Occulter at the precise distance to block the Sun's disk for the camera. (ESA) Now, Proba-3 has sent back its very first artificial solar eclipse images, and the results are pretty amazing. "Seeing the first data from ASPIICS is incredibly exciting," Joe Zender, Proba-3 project scientist, said in an ESA press release. "Together with the measurements made by another instrument on board, DARA, ASPIICS will contribute to unravelling long-lasting questions about our home star." The Sun's inner corona is revealed in this image taken by Proba-3's ASPIICS coronagraph, on May 23, 2025. The image shows the corona similar to how the human eye would see it during an eclipse, but through a green filter. The details of the image were enhanced by a specialized image processing algorithm. (ESA) "Each full image — covering the area from the occulted Sun all the way to the edge of the field of view — is actually constructed from three images," said Andrei Zhukov, the principal investigator for ASPIICS at the Royal Observatory of Belgium. "The difference between those is only the exposure time, which determines how long the coronagraph's aperture is exposed to light. Combining the three images gives us the full view of the corona." "Our 'artificial eclipse' images are comparable with those taken during a natural eclipse," Zhukov explained. "The difference is that we can create our eclipse once every 19.6-hour orbit, while total solar eclipses only occur naturally around once, very rarely twice a year. On top of that, natural total eclipses only last a few minutes, while Proba-3 can hold its artificial eclipse for up to 6 hours.' This artist's impression shows the Proba-3 Occulter blocking the Sun's disk so that the Coronagraph can image the space around the Sun. (ESA) At the moment, Proba-3 is still receiving guidance from ESA operators on the ground, so that the two spacecraft continue to fly in perfect formation. However, the mission team's goal is to get the two doing this precision flying all on their own. Once that happens, they can leave the pair to send back new observations after each orbit. The data returned by the mission will not only help researchers solve the mysteries of the corona's extreme temperatures, but it will also help space weather scientists, as well. The images returned by Proba-3 can act as an important tool to verify their computer models of the corona, which are used to forecast the impacts of solar activity here on Earth. Thus, as Proba-3 continues to send back data, this could improve our ability to forecast auroras or even the potential disruptions to satellites and power grids that can result from extreme space weather. Click here to view the video
Yahoo
18-06-2025
- Science
- Yahoo
European satellites succeed in creating artificial solar eclipse
June 17 (UPI) -- A European space agency created the first "artificial total solar eclipse" using a pair of satellites on Monday. The space agency Proba-3 showed the first images of the Sun's outer atmosphere -- the solar corona. In its announcement, the agency said that this will help improve the understanding of the sun and its atmosphere. A pair of spacecrafts was used, the Coronagraph and the Occulter. They flew 492 feet apart for several hours without any control from the ground to create an artificial total solar eclipse's orbit. The two satellites use an optical instrument to take photos of the sun's corona. The agency's goal for this mission was to observe the sun's corona, which the agency said is important for studying solar wind and understanding coronal mass ejections. "Many of the technologies which allowed Proba-3 to perform precise formation flying have been developed through ESA's General Support Technology Program, as has the mission itself. It is exciting to see these stunning images validate our technologies in what is now the world's first precision formation flying mission," Dietmar Pilz, ESA director of Technology, Engineering and Quality said. "I was absolutely thrilled to see the images, especially since we got them on the first try," Andrei Zhukov, principal investigator for ASPIICS at the Royal Observatory of Belgium said. "Our 'artificial eclipse' images are comparable with those taken during a natural eclipse. The difference is that we can create our eclipse once every 19.6-hour orbit, while total solar eclipses only occur naturally around once, very rarely twice a year. On top of that, natural total eclipses only last a few minutes, while Proba-3 can hold its artificial eclipse for up to 6 hours," said Zhukov. The Proba-3 mission is led by ESA, managed by Spain's Sener, with more than 29 companies from 14 countries involved.
Yahoo
16-06-2025
- Science
- Yahoo
Behold! 1st images of artificial solar eclipse captured by ESA's Proba-3 mission
When you buy through links on our articles, Future and its syndication partners may earn a commission. Total solar eclipses are rare, but exactly how rare is now up for debate after the European Space Agency debuted the first images today (June 16) from two new satellites that together operate as an "eclipse machine." Total solar eclipses currently occur 14 times every 18 years and 11 days somewhere on Earth, which is one every 16 months, on average. According to NASA, they occur once every 366 years in any specific place. Requiring neither lucky geography nor patience, the European Space Agency (ESA) Proba-3 mission, which launched on a PSLV-XL rocket from India's Satish Dhawan Space Centre on Dec. 5, 2024, has just sent back its first images that are sure to impress eclipse chasers across the world. The mission is the first to see two satellites orbit in a "precision formation," with one acting as the moon to eclipse the sun in front of the other, which points a telescope at the sun to capture its elusive corona. A decade in the making, these first images — from the mission's first successful formation flying demo on May 23 — are a glimpse of what's to come. The solar corona, the sun's outer atmosphere, is a mystery. The sun's photosphere, its surface, is about 10,000 degrees Fahrenheit (5,500 degrees Celsius), but the corona is two million degrees Fahrenheit (over 1,1 million degrees C) — about 200 times hotter. Scientists need to know why and how this is the case, mainly because the corona is where the solar wind is generated. "As well as being an amazing thing to see, the corona is also a laboratory for plasma physics and the main source of space weather," said Andrei Zhukov, Principal Investigator for the Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun (ASPIICS) at the Royal Observatory of Belgium, speaking at the Solar Eclipse Conference in Leuven, Belgium. Observations of the corona are crucial to understanding phenomena such as solar wind and coronal mass ejections, which can disrupt Earth's power and communication systems and produce spectacular displays of the northern lights. However, Proba-3's images will also help solar physicists see features in the corona that are sometimes visible to observers of total solar eclipses. "Sometimes, clouds of relatively cold plasma are observed near the sun, creating what we call a prominence," said Zhukov. Prominences are much colder than the surrounding million-degree hot plasma in the corona, though still around 10,000 degrees Celsius. "We are very happy to have been able to capture one such structure in one of the first ASPIICS images," said Zhukov. But there's a problem. The sun's disk is a million times brighter than the corona and completely overwhelms the human eye. The only time the corona can be seen is during a total solar eclipse. "They're inconvenient, they're rare and last only a few minutes," said Zhukov."The last total solar eclipse in Belgium was in 1406, and the next is in 2090. That's why we have coronagraphs." A coronagraph is a device attached to a telescope that blocks out the direct light from a star — in this case, the sun — so that whatever is around it can be seen. Sometimes it's exoplanets. In this case, it's the corona. Unfortunately, Earth's atmosphere scatters that light. In short, they work much better in space. "Current coronagraphs are no match for Proba-3, which will observe the sun's corona down almost to the edge of the solar surface," says Jorge Amaya, Space Weather Modelling Coordinator at ESA. "So far, this was only possible during natural solar eclipses." In March, Proba-3's two spacecraft — the Coronagraph satellite and the Occulter satellite — aligned 500 feet (150 meters) apart with millimeter accuracy for several hours without ground intervention. The Occulter successfully blocked the sun's disk to cast a shadow onto ASPIICS — the coronagraph's sensitive optical instrument that captures the corona. "Having two spacecraft form one giant coronagraph in space allowed us to capture the inner corona with very low levels of stray light in our observations, exactly as we expected," said Damien Galano, Proba-3 mission manager. "I was absolutely thrilled to see the images, especially since we got them on the first try," said Zhukov. "It's just a teaser because we are still in the commissioning phase." The images themselves were processed by scientists and engineers at the ASPIICS Science Operations Centre at the Royal Observatory of Belgium. Each complete image — covering the area from the occulted sun to the edge of the field of view — is constructed from three images. "The difference between those is only the exposure time, which determines how long the coronagraph's aperture is exposed to light. Combining the three images gives us the full view of the corona," said Zhukov. "Our 'artificial eclipse' images are comparable with those taken during a natural eclipse — the difference is that we can create our eclipse once every 19.6-hour orbit." Proba-3 will create about 1,000 hours of images of the corona over its two-year mission — and anyone will be able to download the data. "We have an open data policy — the uncalibrated data will be published immediately so everyone will be able to calibrate their own data," said Zhukov. The solar-powered Proba-3 satellites have an elliptical orbit with a perigee (closest point) of 373 miles (600 kilometers) and an apogee of 37,000 miles (60,000 kilometers). They only fly in formation when close to apogee because that's when Earth's gravity, its magnetic field and atmospheric drag are at their weakest. That allows the satellites to use minimal propellant to attempt formation flying. The coronagraph satellite positions itself 492 feet (150 meters) behind the occulter satellite — two orders of magnitude farther than any other space-based coronagraph — with the formation flying performed down to a single millimeter in precision. The 4.4 feet (1.4 meters) occulter casts a 3.15 inch (8 centimeters) shadow onto the coronagraph. Remarkably, it's all done autonomously, with Proba standing for "Project for onboard autonomy". "The precision achieved is extraordinary," said Dietmar Pilz, ESA Director of Technology, Engineering and Quality. "It validates our years of technological development and positions ESA at the forefront of formation flying missions." Proba-3 is not unique. A joint mission between the U.S. and the Soviet Union, the Apollo-Soyuz Test Project in 1975 saw the first coronal observation using formation flying, with the Apollo spacecraft acting as an improvised coronagraph, allowing the Soyuz crew to photograph the solar corona. "It was all done by hand — the image was taken through a window of a Soyuz spacecraft," said Zhukov. The results were disappointing, mainly because the thruster gases around the spacecraft scattered the light. With Proba-3, the concept has become a reality, and artificial solar eclipses will be possible, revealing the inner solar corona without the need to wait for a total solar eclipse. Will that deter eclipse chasers? Absolutely not!
