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!
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
3 hours ago
- Yahoo
Researchers stunned after uncovering creature not seen since early 1900s: 'We spent a few hours digging'
An elusive eel species was documented anew in northeastern India, according to McClatchy News. Renamed as Ophichthys hodgarti, the animal, while not unknown to locals, hadn't been identified by scientists since an 80-mile British expedition in the early 1900s through what is now the state of Arunachal Pradesh. Researchers more recently followed in the footsteps of that expedition and were able to find live specimens along the treacherous terrain of the Siang Valley. A report of their findings was published in the journal Zootaxa on May 19. "We spent a few hours digging through the mud and rocks until we found the first one," co-author Nilanjan Mukherjee told McClatchy in May. "The moment we caught it and transferred it to a container, I knew we had found the eel." Mukherjee was surprised by how much time the eel spent outside of water, including on a wet road some distance from a water source. Many such animals stick to marine environments. In their publication, the co-authors wrote, "The fact that over a century has elapsed between the description of O. hodgarti and its rediscovery serves to highlight the gaps in our knowledge … and suggests opportunities for researchers to intensify exploratory efforts to fill these gaps." Supporting research efforts to address such gaps could uncover knowledge about other unknown or lesser-known species, potentially revealing even more eclectic wildlife communities. Indeed, the region where the elusive eels were found is home to many and varied animals. Rare tigers and fish have previously been spotted in Arunachal Pradesh, perhaps a hotbed for biodiversity, which is an important pillar of thriving ecosystems. Rich ecosystems can serve all living things, including humans, in unforeseen ways. For example, researchers discovered that a species of Thai bat has been hunting destructive insects that might otherwise wreak havoc on local crops. In another instance, sea otters have been found to be protective of kelp forests by feeding on urchins that might otherwise decimate kelp. Kelp provides an important habitat for commercial fisheries and makes for a harvestable product itself. Should we be actively working to kill invasive species? Absolutely It depends on the species I don't know No — leave nature alone Click your choice to see results and speak your mind. The more research we dedicate to these relationships, the more we can see the value of intact ecosystems and of protecting them. "We are more likely to conserve species if we know what we stand to lose and (to conserve) landscapes if we know what inhabits them," Mukherjee told McClatchy News about the importance of studying Ophichthys hodgarti, "and this information can only be gained through exploration and research." Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
4 hours ago
- Yahoo
Researchers raise red flags after studying samples of popular food item: 'Humans are directly ingesting these'
Researchers in India have published a novel "landmark scientific study" with troubling findings concerning microplastics and a commonly consumed type of shellfish, The Statesman reported. Researchers at two Indian universities obtained nearly 400 samples of Lamellidens marginalis, a species of freshwater mollusk commonly harvested and consumed in Southeast Asia. Also known as mussels, the mollusks are considered an "indicator species" due to their invaluable ability to shed light on levels of water pollution in their natural habitats. For this study, researchers examined the samples of Lamellidens marginalis to gauge the extent of plastic pollution in local rivers. In what The Statesman called the "first concrete evidence of how deeply plastic pollution has penetrated local food systems," scientists determined that over 80% of freshwater mussel samples obtained from "six key market hubs" contained microplastic particulate matter. "Every mussel you eat might be delivering more than just protein. It could be a vehicle for microscopic plastic particles that are now infiltrating human bodies through daily diets," lead study author Dr. Sujoy Midya explained. "With mussels acting as natural water filters — and now [as] unwilling microplastic reservoirs — the study paints a grim picture of environmental degradation," The Statesman concluded. According to the U.S. Fish & Wildlife Service, "a single freshwater mussel can pump and filter between 8 and 15 gallons of water per day." Consequently, freshwater mussels "drastically improve the water quality in their environments." Like oysters and clams, these "filter feeders" perform an essential function in aquatic ecosystems, keeping waters clean and heralding dangerous conditions. "These mussels are not just seafood — they're sentinels," Midya said. However, freshwater mussels remain popular in Southeast Asia, and the levels of contamination documented in the study are unquestionably concerning. Do you worry about how much food you throw away? Definitely Sometimes Not really Never Click your choice to see results and speak your mind. "Their contamination levels reflect the scale of pollution in our freshwater ecosystems. And because they are consumed whole, humans are directly ingesting these microplastics," explained Midya. "Research has already shown that [microplastic] particles can accumulate in human tissues, potentially leading to oxidative stress, inflammation, and even genetic damage," he added, referencing a growing number of studies linking plastic pollution to adverse human health outcomes. Per The Statesman, the study's authors recommended "immediate action — calling for stringent environmental policies, increased public awareness, and expanded scientific monitoring" to limit the risk to humans and mollusks alike. Researchers in Korea pioneered a method to filter microplastic particles from water, although that technology is not in widespread use yet. At an individual level, the most effective approach is to use less plastic whenever possible — while it's difficult to completely avoid plastic, incremental changes make a big difference. Join our free newsletter for weekly updates on the latest innovations improving our lives and shaping our future, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
4 hours ago
- Yahoo
Long-Dead NASA Satellite Suddenly Lets Out Epic Blast of Energy
NASA's experimental Relay 2 satellite had been dead in the sky since 1967 — until last summer, when it emitted a super-short and very powerful burst of energy out of nowhere. In an interview with New Scientist, one of the researchers from Australia's Curtin University who discovered the strange pulse coming off the dead communications satellite described his shock at finding the nearby source of that nanosecond-long energy blast. Curtin astronomer Clancy James and his team had been using the Australian Square Kilometer Array Pathfinder (ASKAP) radio telescope array when they detected something so "loud" that it briefly outshone everything else in the night sky. Even stranger, it turned out, the signal was coming from so close to Earth that ASKAP's radio telescopes couldn't all focus on it at once. "We got all excited, thinking maybe we'd discovered a new pulsar or some other object," James told New Scientist. "This was an incredibly powerful radio pulse that vastly outshone everything else in the sky for a very short amount of time." As explained in a new paper that's now awaiting peer review, the Curtin researchers eventually traced the source of the pulse to NASA's derelict Relay 2 — but that discovery raised more questions than answers. Because Relay 2 had been dead for nearly 60 years, the Curtin team thinks that something either collided with the defunct communications craft that made it produce such a wild racket, or that electricity had been building up within it for so long that it resulted in a huge type of energy burst known as an "electrostatic discharge." As astrophysicist Karen Aplin of the UK's University of Bristol told New Scientist, all the space junk crowding Earth's orbit makes it nearly impossible to determine if either of those explanations, or any other, is correct. (That problematic crowding of Earth's orbit, it's worth pointing out, was not a pressing issue during Relay 2's short life in the mid-1960s.) "In a world where there is a lot of space debris and there are more small, low-cost satellites with limited protection from electrostatic discharges, this radio detection may ultimately offer a new technique to evaluate electrostatic discharges in space" explained Aplin, who was not involved in the research. More on strange energy: Scientists Spot Mysterious Object in Our Galaxy Pulsing Every 44 Minutes
