Dubbed the seahorse flare based on its swirling, marine-creature-esque appearance, it was the first space-age solar event that would have exposed any astronauts in space to extraordinary levels of radiation. Luckily, the crew of Apollo 17 were safely on the ground preparing for their December takeoff.<\/p>\n
A powerful flare was captured in August 1972 by the Big Bear Solar Observatory in California. It was called the seahorse flare after the shape of its brightest regions. Since then, the optics used for solar telescopes have improved greatly. <\/p>\n
Credit:
\n NASA<\/p>\n
As the US makes plans to send astronauts back to the moon, space technology expands, and more of the earthbound population relies on satellites for basic needs, it has become vitally important to understand and predict the hazards hurled at Earth from our nearest star. In a press conference on Sept. 21, Nicky Fox<\/a>, the associate administrator of NASA\u2019s Science Mission Directorate, pointed to the seahorse flare as a reminder of the power of space weather.<\/p>\n That\u2019s why NASA and the US National Oceanic and Atmospheric Administration launched three new space-weather missions on Sept. 24: the Interstellar Mapping and Acceleration Probe (IMAP), Carruthers Geocorona Observatory, and the Space Weather Follow On\u2013Lagrange 1 (SWFO-L1).<\/p>\n \u201cThis is the ultimate cosmic carpool,\u201d said Joseph Westlake<\/a>, director of NASA\u2019s heliophysics division, during a second press conference, about the science goals of the missions.<\/p>\n But what are solar flares and CMEs? And can scientists predict when they\u2019ll hit?<\/p>\n How the sun causes space weather<\/p>\n \u201cIt\u2019s all about magnetic fields on the sun,\u201d says solar astrophysicist Maria Kazachenko<\/a>, a professor at the University of Colorado Boulder and the US National Solar Observatory. \u201cHere on Earth, we care about gravity. We throw anything and it just falls down. On the sun, everything follows the magnetic field loops.\u201d<\/p>\n
The sun\u2019s magnetic field likely arises from the roiling plasma that forms the star. The unique state of matter is made up of ionized gases and their freed electrons. Because the charged particles are moving, they create magnetic fields; the plasma both carries and creates the magnetic fields in the solar atmosphere, Kazachenko says.<\/p>\n Particularly active regions can arise on the solar surface when magnetic energy bubbles up from within the star. And as different parts of plasma move on the solar surface, the associated magnetic fields become taught and tangled. \u201cWhen these magnetic field lines become too tangled, they can snap,\u201d explains Madhulika \u201cLika\u201d Guhathakurta<\/a>, an astrophysicist who helped build and lead NASA\u2019s Living with a Star initiative. \u201cThink of it like stretching a rubber band until it breaks.\u201d<\/p>\n Once they\u2019re broken, those magnetic lines rapidly rearrange in a process called magnetic reconnection. The process releases a tremendous amount of energy and triggers a solar flare.<\/p>\n \u201cThis is like a cosmic short circuit, releasing all its energy at once. It\u2019s instantaneous,\u201d Guhathakurta says. The result is an explosion of photons that have energies across the electromagnetic spectrum, from radio waves to gamma rays, that sends radiation throughout the solar system before slowly fading away, she says.<\/p>\n The massive release of energy also acts as a particle accelerator. And if the flare is pointed toward Earth, our planet is bombarded not only with electromagnetic radiation but also a shower of protons, electrons, and ions from the sun.<\/p>\n But solar flares are only one part of space weather. If enough energy is released through magnetic reconnection, a portion of the solar corona\u2014the outermost part of the sun\u2019s atmosphere\u2014can explode into space as a CME.<\/p>\n \u201cThe outermost, fastest layer that\u2019s pushing particles ahead of it, pushing through space, arrives here at Earth with a punch,\u201d says Shawn Dahl, a space weather forecaster at NOAA\u2019s Space Weather Prediction Center<\/a>. When the shock front slams into Earth\u2019s magnetic field, it pushes the field around, which \u201cimmediately spins up [magnetic] activity,\u201d he says.<\/p>\n Space weather comes from the sun<\/p>\n The sun is responsible for the space weather experienced by every living thing on Earth. Although a solar wind of charged particles constantly blows out from the sun, sometimes the star is even more active as areas of its magnetic field become strained and tangled. These areas are often marked by sunspots\u2014visibly dark regions on the sun\u2019s surface. Ultimately, the tangled magnetic fields can snap and release energy in the form of a solar flare, coronal mass ejection, or both. When one of these solar events is directed at Earth, the associated charged particles and magnetic field interact with the planet\u2019s magnetic field. Large flares can disrupt communications, and large coronal mass ejections can cause power-grid blackouts and spectacular displays of aurora.<\/p>\n Credit: Then, the bulk of the CME arrives, carrying its own magnetic field. \u201cWe get really concerned about the orientation of that magnetic field in space,\u201d Dahl says. Its strength and orientation in relation to Earth\u2019s magnetic field determines the intensity of the resulting geomagnetic storm.<\/p>\n Those storms have a scale. A G1 event is the most minor but may still cause very weak, easily managed power fluctuations on some power grids. In contrast, a G5 event can cause power grids to fail, make radio navigation impossible, interfere with satellite functions, and send auroral displays down to midlatitudes. Or, as back in the 1970s, possibly trigger naval mines to explode.<\/p>\n Predicting flares and CMEs<\/p>\n The active regions that spark solar flares and CMEs are often marked by sunspots, planet-size areas of the sun that appear darker than their surroundings at visible wavelengths.<\/p>\n First recorded thousands of years ago by Chinese astronomers peering at the sun with naked eyes, telescopic observations and data collection of sunspots began in the 1600s. A pattern has emerged from the hundreds of years of data: a cycle of solar activity that peaks every 11 years. The sun is currently at or near its solar maximum.<\/p>\n Today, scientists still map sunspots in detail. \u201cWe\u2019re looking at each single sunspot group and what their magnetic structure is,\u201d Dahl says. Operationally, it\u2019s currently impossible to predict exactly when a solar flare will occur, but he says researchers can model the probability of a flare occurring in the next 3 days based on the data provided by these observations.<\/p>\n The energy from the most powerful flares can obliterate high-frequency (HF) radio wave signals, so flare forecasts are important to industries, such as aviation, that use HF radio for communication. But because most of that energy comes from photons and X-rays traveling at the speed of light or charged particles traveling near the speed of light, \u201cwhen we see a solar flare, the effect is already ongoing in the outer atmosphere of our planet,\u201d Dahl says.<\/p>\n On Feb. 21, 2024, NASA\u2019s Solar Dynamics Observatory captured an ultraviolet image of a solar flare. Scientists can\u2019t yet precisely predict when a flare will occur, only its probability.<\/p>\n Credit: When a CME erupts from the sun, earthlings have a bit more time to prepare because the bubble of plasma travels more slowly than a flare.<\/p>\n Forecasters such as those at NOAA and other members of the International Space Environment Service<\/a> can use satellite and ground-based measurements to determine the CME\u2019s trajectory and whether it\u2019ll hit Earth. But \u201cwe know nothing about the dynamics and the structure of that CME whatsoever until it arrives 1 million miles away from Earth where we have a few satellites,\u201d Dahl says. At an average speed, a CME will crash into Earth 45\u201360 min after hitting those satellites. \u201cAt their quickest, they can be here in 10 to 15 minutes,\u201d Dahl adds.<\/p>\n Because CMEs can cause blackouts, \u201cthe power grid needs as much advance notice of these storms as they can possibly get,\u201d Dahl says. So his team has taken strides to send out a warning of a potentially hazardous CME before it even reaches a satellite.<\/p>\n To initiate the warning, Dahl hops on the phone. \u201cIt\u2019s called the NERC hotline,\u201d he says. \u201cNERC stands for North American Electric Reliability Corporation. That\u2019s who controls the power grid for all the southern Canadian provinces and all the 48 mainland United States.\u201d<\/p>\n In the last 2 years, scientists have recorded many G4 events and one G5 event. And through the storms, the power stayed on in the US.<\/p>\n Improving flare models<\/p>\n Some researchers are hoping to improve solar flare models with new observations. For example, advanced telescope optics recently allowed researchers in CU Boulder\u2019s Kazachenko group to capture images of a recent flare in extraordinary detail using the most powerful solar telescope on Earth: the Daniel K. Inouye Solar Telescope.<\/p>\n The images produced show light emitted by hydrogen atoms in the plasma of the solar surface and atmosphere during a large solar flare<\/a> (Astrophys. J. Lett. 2025, DOI: 10.3847\/2041-8213\/adf95e). Fine loops of darker plasma outline the structure of the magnetic field immediately after reconnection, while bright ribbons of orange show where accelerated particles smash into the solar surface.<\/p>\n With advanced optics, researchers such as Maria Kazachenko can now capture very-high-resolution images of solar flares using light emitted by hydrogen ions in the plasma. The bright ribbons of orange light visible on the sun\u2019s surface show the foot of arching, invisible magnetic field lines. The scale of this image is about 4 Earth-diameters on each side.<\/p>\n Credit: \u201cWe are trying to understand the enigma of how solar flares happen,\u201d Kazachenko says. The new images may hold a missing piece of the puzzle.<\/p>\n \u201cThere is a promise that these fine structures would be able to tell us the full story of magnetic reconnection,\u201d Kazachenko says. A better understanding of magnetic reconnection could help researchers better predict flares. After all, you can\u2019t forecast what you don\u2019t understand, she adds.<\/p>\n By reanalyzing solar spectra, a group of scientists led by solar physicist and applied mathematician Alexander Russell at the University of St. Andrews also recently revealed new insights into the temperature of the plasma at the heart of solar flares.<\/p>\n Scientists can determine these temperatures in a few ways, Russell says. X-ray blackbody radiation, elements\u2019 ionization states, and emission-line ratios from specific elements are all related to the temperature of electrons in a flare. Each of these measures has independently pointed to those electrons being about 10 million\u201315 million \u00b0C, Russell says.<\/p>\n But ever since the first solar space missions recorded spectra, it has been clear that spectral emission lines \u201care much broader than you would expect based on the electron temperature,\u201d Russell says. \u201cThe question has been, why?\u201d<\/p>\n By combining an up-to-date understanding of solar flares densities with data from recent space physics missions and supercomputer simulations, Russell came up with an answer: magnetic reconnection heats ions far more efficiently than electrons. Ion temperatures can reach as high as 60 million\u2013100 million \u00b0C, he says, more than 6.5 times as hot as the electrons in the flare<\/a> (Astrophys. J. Lett. 2025, DOI: 10.3847\/2041-8213\/adf74a).<\/p>\n \u201cA lot of our models that we use to try and predict solar flares and understand them have been founded on the idea that the ions and electrons have the same temperature,\u201d Russell says. But if ions are preferentially heated, those models need to be updated, he says.<\/p>\n Together, new ground-based observations, calculations, and dedicated space weather satellite missions all aim to help scientists understand solar flares and CMEs. That understanding will feed into predictive models like those used at NOAA\u2019s Space Weather Prediction Center. \u201cWe\u2019re focused on keeping society safe with actionable space weather information. That\u2019s what we\u2019re doing,\u201d Dahl says. \u201cThe aurora is just part of the sideshow.\u201d<\/p>\n \n Chemical & Engineering News<\/p>\n ISSN 0009-2347<\/p>\n Copyright \u00a9
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\n Video images captured by scientists using advanced solar optics at the Goode Solar Telescope at Big Bear Solar Observatory in California show how plasma follows magnetic fields on the sun, either as it rains back to the solar surface (left) or twists and dances up from it (right).
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\n Credit: Schmidt et al.\/NJIT\/NSO\/AURA\/NSF
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<\/p>\n
\n A graphic shows half of an orange sun on the left and the entire planet Earth on the right. The sun has sunspots on its surface, a solar flare in the form of a white star shape, and a coronal mass ejection drawn a loop of orange coming off the surface. The solar wind is indicated with dashed orange lines pointing toward Earth. The planet\u2019s magnetic field is shown.<\/p>\n
\n Yang H. Ku\/C&EN<\/p>\n
\n An image of the sun shows a bright flash of light and plasma loops in the corona, tinted yellow, and the extremely hot material in flares, tinted blue.\u00a0<\/p>\n
\n NASA\/Solar Dynamics Observatory<\/p>\n
\n NSF\/NSO\/AURA<\/p>\n
\n 2025 American Chemical Society<\/p>\n","protected":false},"excerpt":{"rendered":"\u00a0 Key Insights This September, the US launched three new missions into space, all of which are designed…\n","protected":false},"author":2,"featured_media":180901,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[91581,49,48,2044,91582,1677,91583,11032,87110,66,229,306,10759,2047,91584,1133],"class_list":["post-180900","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-astrochemistry","tag-ca","tag-canada","tag-cme","tag-coronal","tag-earth","tag-ejection","tag-flare","tag-mass","tag-science","tag-solar","tag-space","tag-spot","tag-sun","tag-sunspot","tag-weather"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/180900","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=180900"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/180900\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/180901"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=180900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=180900"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=180900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}