3 min read<\/p>\n
NASA Observations Find What Helps Heat Roots of \u2018Moss\u2019 on Sun<\/h1>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n![\"The](\"https:\/\/science.nasa.gov\/wp-content\/uploads\/2024\/04\/unknown.png?w=2048\")
<\/figure>\nAt the center of this image (left) from NASA\u2019s High Resolution Coronal Imager sounding rocket is a small-scale, patchy structure on the Sun that solar physicists call \u201cmoss.\u201d\u00a0 It forms low in the solar atmosphere around the center of sunspot groups on the Sun where magnetic activity is strong. An image from NASA\u2019s Interface Region Imaging Spectrograph, or IRIS, mission shows a detailed scenery of the cooler roots of moss (right).<\/div>\nNASA\/Bose et al 2024<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nDid you know the Sun has moss? Due to its resemblance to the earthly plants, scientists have named a small-scale, bright, patchy structure made of plasma in the solar atmosphere \u201cmoss.\u201d This moss, which was first identified in 1999 by NASA\u2019s TRACE mission<\/a>, blossoms around the center of a sunspot group, where magnetic conditions are strong. It straddles two atmospheric layers known as the chromosphere and corona and hides below the long feathery ropes of plasma known as coronal loops.<\/p>\nFor decades, scientists have struggled to understand how this mossy region is connected to the Sun\u2019s lower atmospheric layers and how material there is heated from 10,000 degrees Fahrenheit up to nearly 1 million degrees Fahrenheit \u2014 100 times hotter than the bright surface just below. Now, research enabled by NASA\u2019s High Resolution Coronal Imager (Hi-C) sounding rocket<\/a> and NASA\u2019s Interface Region Imaging Spectrograph (IRIS<\/a>) mission have given scientists insights into the superheating mechanism at play in the moss.<\/p>\nObservations from these instruments combined with complex 3D simulations have now revealed that electrical currents may contribute to heating the moss. Throughout this region there is a mess of magnetic field lines, like invisible spaghetti. This tangle of magnetic spaghetti creates electrical currents that can help heat material to a wide range of temperatures from 10,000 to 1 million degrees Fahrenheit. This local heating in the moss appears to occur in addition to heat flowing from the hot, multi-million-degree overlying corona. This insight, published in the journal Nature Astronomy<\/a> on April 15, can help scientists understand the larger question of why the Sun\u2019s entire corona is so much hotter than the surface.<\/p>\n\u201cThanks to the high-resolution observations and our advanced numerical simulations, we\u2019re able to figure out part of this mystery that\u2019s stumped us for the past quarter of a century,\u201d said author Souvik Bose, a research scientist at Lockheed Martin Solar and Astrophysics Laboratory and Bay Area Environmental Institute, NASA\u2019s Ames Research Center in California\u2019s Silicon Valley. \u201cHowever, this is just a piece of the puzzle; it doesn\u2019t solve the whole problem.\u201d<\/p>\n
For that, many more observations are needed. Some are coming soon: Hi-C is scheduled to launch again this month to capture a solar flare, and it may also capture another moss region together with IRIS. However, to obtain observations that can fully address how the corona and moss are heated, scientists and engineers are working to develop new instruments onboard the future MUlti-slit Solar Explorer (MUSE<\/a>) mission.<\/p>\nIRIS and TRACE are part of NASA\u2019s Explorers Program.<\/p>\n
By Mara Johnson-Groh<\/strong>
NASA\u2019s Goddard Space Flight Center, Greenbelt, Md.<\/strong><\/p>\nMedia contact: <\/strong>Sarah Frazier<\/strong><\/a>
NASA\u2019s Goddard Space Flight Center, Greenbelt, Md.<\/strong><\/p>\n\n\n\n\n\n\nShare<\/h2>\n<\/div>\n\n
<\/figure>Did you know the Sun has moss? Due to its resemblance to the earthly plants, scientists have named a small-scale, bright, patchy structure made of plasma in the solar atmosphere \u201cmoss.\u201d This moss, which was first identified in 1999 by NASA\u2019s TRACE mission<\/a>, blossoms around the center of a sunspot group, where magnetic conditions are strong. It straddles two atmospheric layers known as the chromosphere and corona and hides below the long feathery ropes of plasma known as coronal loops.<\/p>\n For decades, scientists have struggled to understand how this mossy region is connected to the Sun\u2019s lower atmospheric layers and how material there is heated from 10,000 degrees Fahrenheit up to nearly 1 million degrees Fahrenheit \u2014 100 times hotter than the bright surface just below. Now, research enabled by NASA\u2019s High Resolution Coronal Imager (Hi-C) sounding rocket<\/a> and NASA\u2019s Interface Region Imaging Spectrograph (IRIS<\/a>) mission have given scientists insights into the superheating mechanism at play in the moss.<\/p>\n Observations from these instruments combined with complex 3D simulations have now revealed that electrical currents may contribute to heating the moss. Throughout this region there is a mess of magnetic field lines, like invisible spaghetti. This tangle of magnetic spaghetti creates electrical currents that can help heat material to a wide range of temperatures from 10,000 to 1 million degrees Fahrenheit. This local heating in the moss appears to occur in addition to heat flowing from the hot, multi-million-degree overlying corona. This insight, published in the journal Nature Astronomy<\/a> on April 15, can help scientists understand the larger question of why the Sun\u2019s entire corona is so much hotter than the surface.<\/p>\n \u201cThanks to the high-resolution observations and our advanced numerical simulations, we\u2019re able to figure out part of this mystery that\u2019s stumped us for the past quarter of a century,\u201d said author Souvik Bose, a research scientist at Lockheed Martin Solar and Astrophysics Laboratory and Bay Area Environmental Institute, NASA\u2019s Ames Research Center in California\u2019s Silicon Valley. \u201cHowever, this is just a piece of the puzzle; it doesn\u2019t solve the whole problem.\u201d<\/p>\n For that, many more observations are needed. Some are coming soon: Hi-C is scheduled to launch again this month to capture a solar flare, and it may also capture another moss region together with IRIS. However, to obtain observations that can fully address how the corona and moss are heated, scientists and engineers are working to develop new instruments onboard the future MUlti-slit Solar Explorer (MUSE<\/a>) mission.<\/p>\n IRIS and TRACE are part of NASA\u2019s Explorers Program.<\/p>\n By Mara Johnson-Groh<\/strong> Media contact: <\/strong>Sarah Frazier<\/strong><\/a>
NASA\u2019s Goddard Space Flight Center, Greenbelt, Md.<\/strong><\/p>\n
NASA\u2019s Goddard Space Flight Center, Greenbelt, Md.<\/strong><\/p>\nShare<\/h2>\n<\/div>\n