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SunThe sun is the closest star to Earth, located an average distance of 150 million kilometers (93,000,000 miles) away. It contains 99.8% of the solar system's mass—whose resulting gravity keeps the solar system intact—and a volume equivalent to about 1.3 million Earths. Revered across mythologies as a symbol of power and life, the sun is the primary source of energy for Earth's systems, sending over 10,000 times more energy than human civilization consumes.
The sun began forming 4.6 billion years ago from the collapse of a molecular cloud of gas and is predominantly composed of hydrogen and helium, with its interior divided into three layers: the core, the radiative zone, and the convection zone. With a density 13 times that of lead and temperatures in the millions of degrees, hydrogen fusion in the core produces radiation that travels outward through the radiative zone. Once it reaches the convection zone, this energy churns plasma to the surface, or the photosphere, which is what we see from Earth.
Besides light, the sun also produces a stream of charged particles—solar wind—and a magnetic field, which interact with Earth to produce auroras and technology-disrupting geomagnetic storms. The interactions can be more severe at the peak of the sun's 11-year cycle, when sunspots, eruptive solar flares, and coronal mass ejections are more common.Explore Sun
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Why Earth will be made uninhabitable by the sun far sooner than when the sun diesThe star has enough fuel to continue fusing hydrogen into helium for another 5 billion years, but the gradual increase in core temperature from these reactions will brighten the sun by 10% every billion years. Some models predict that the increased radiation will be enough to vaporize all of Earth's surface water about 1 billion years from now, long before the sun becomes a red giant and disintegrates the planet. The ConversationThe sun is not as exceptional as once believed, but it remains rarer than most starsOnce believed to be the center of the universe, the sun is a G-class star, the same category to which about 6% of the Milky Way's stars belong. However, the sun is younger than 85%, more massive than 95%, and more metal-rich than about 93% of all stars. Unlike the sun, half of all stars also exist in multi-star systems. Big ThinkView media of the sun's south pole, taken for the first time in 2025Captured in March 2025 by the Solar Orbiter—a satellite developed by ESA and NASA—the images and video are the first to be taken by an object not moving around the sun's equator. The orbiter moved outside the plane of the planets by using Venus to slingshot it into a tilted orbit, and the data it collected will help scientists better understand the sun's magnetic activity. ESABreaking down sunlight and why the sun appears yellow despite emitting green light the mostThis peak intensity is produced alongside a spectrum of other colors, which, when combined, make the sun appear white in space. Since Earth's atmosphere scatters bluer and greener wavelengths of light more than red and orange wavelengths, sunlight reaching Earth's surface appears yellow, while the sky appears blue. (Some readers may experience a paywall.) Science News ExploresUnderstanding why charged particles from the sun protect Earth from more dangerous particlesThe solar wind engulfs the solar system in a protective bubble called the heliosphere, which was first theorized in the late 1950s based on studies of cosmic rays—high-energy particles traveling through space at near light speed. The heliosphere shields the solar system from much of this ionizing radiation originating elsewhere in the Milky Way. CNNWhy the sun is not the center of the solar system, despite its gravitational pull on planetsBecause gravity is a mutual force of attraction between objects, everything in the solar system also pulls on the sun. This causes the star to "wobble" around the center of mass of the solar system—the barycenter—which is the point every object in the solar system orbits. The barycenter is sometimes inside the sun because of the star's size, which contributes to the misconception. Be SmartHow its uneven rotation produces the sun's 11-year cycle and flips its magnetic polesWhile charged material rises and falls in the sun's convection zone, which induces magnetic fields, different latitudes rotate at different rates, making these fields increasingly turbulent. This builds to a critical point—the solar maximum—where magnetic field-driven events, such as solar flares, become more common before the field collapses and flips, restarting the cycle. Smithsonian MagazineA composite of telescope images of the sun, which each reveal unique solar featuresWhile traditional cameras can reveal sunspots—cooler regions on the sun's surface—in visible light, x-ray detectors can highlight explosions of high-energy plasma and magnetic fields known as coronal mass ejections. Hydrogen-alpha filters can reveal clouds and filaments of material suspended in magnetic fields above the sun's surface. NASALearn about the sun's corona, which is nonlethal despite a temperature of millions of degreesThe outermost layer of the sun's atmosphere is best seen during a solar eclipse, when the moon blocks the much brighter (and significantly cooler) solar surface. Despite the high-energy particles in the corona moving fast enough to escape the sun's gravity and gradually become solar wind, their density is too low to contribute meaningfully to the region's overall radiation. University Corporation for Atmospheric ResearchView the internal structure of the sun and its puzzling surrounding atmosphereFrom the stellar core to the surface, the sun's density decreases from more than 10 times that of lead to 0.00001% that of air, while temperatures drop from millions to thousands. Temperatures increase from the sun's surface to the outermost layer of its atmosphere—the corona—a phenomenon whose explanation is still under investigation. NASAAn overview of the sun, from its formation to its role in fueling and protecting life on EarthWith a surface gravity almost 28 times Earth's, the sun's mass exerts enough pressure to raise temperatures in its core above 15 million degrees Celsius (27 million degrees Fahrenheit) and enable nuclear fusion. These reactions produce the energy that sustains Earth's photosynthesis-dependent food chains, while the sun's magnetic field protects the solar system from cosmic ionizing radiation. National GeographicHow phytoremediation contributed to sunflowers becoming a symbol of nuclear disarmamentAfter nuclear disasters, sunflowers have been planted for their ability to extract large amounts of metals from soil, including radioactive cesium and strontium, which their biochemistry confuses with potassium and calcium, respectively. Sunflowers' rapid growth and large biomass enable them to isolate contaminants and survive long enough to be safely harvested and disposed of. Science ABCHow sunlight helps chlorofluorocarbons destroy the ozone molecules that block solar radiationCFCs, which are used in old refrigerants, air conditioners, and aerosol sprays, do not react with atmospheric molecules. Once they reach the stratosphere, ultraviolet radiation breaks chlorine atoms off of them, which can each break apart more than 100,000 ozone molecules, thinning Earth's protective layer against ultraviolet radiation. National GeographicHow scientists discovered helium from sunlight over a decade before seeing it on EarthIn 1868, using tools that dispersed light into its constituent colors like a prism, astronomers Pierre Jules César Janssen and Joseph Norman Lockyer independently identified a bright yellow line in the solar spectrum that didn't match any known element. Fourteen years later, amid continued skepticism over the existence of a new element, the same spectral signature was observed in lava on Earth. Science History InstituteWhy the sun's equator rotates once every 24.5 days, but the poles take over 34 daysJust like the Earth, linear speeds on the surface of the sun decrease from the equator to the poles. However, rotation time also appears to vary with depth, with the radiative zone beneath the convection zone rotating about once every 26.6 days. Measurement uncertainty has prevented measurement of the rotation of the solar core. Live ScienceMapping the Middle East showing Sunni and Shia populations by countryFrance24's interactive visualization shows where each branch of Islam predominates across the region, from Iran's Shia majority to Saudi Arabia's Sunni dominance. The map helps make Middle Eastern politics (and conflicts) more legible. France24The ancient succession drama that led to the Sunni-Shia divideThe split that divided Islam into its major branches comes down to succession: after Muhammad's death, Sunnis backed an elected leader, Abu Bakr, while Shia Muslims sided with a member of Muhammad's bloodline, his cousin and son-in-law Ali. That 7th-century disagreement shapes geopolitics today, Ramadan's traditions, and communities worldwide. HISTORYThe Sunni-Shia divide has fueled conflict and rivalry throughout the Middle East for centuriesIslam's ancient sectarian split, rooted in a seventh-century dispute over succession following the Prophet Mohammed's death, has shaped modern geopolitics—most visibly in the proxy rivalry between Sunni Saudi Arabia and Shia Iran, whose competition for regional dominance has inflamed conflicts across Syria, Iraq, Lebanon, and Yemen. Council on Foreign RelationsSun Ra and his band operated a grocery store in PhiladelphiaRa arrived in Philadelphia in 1968, settling into a home in the city's Germantown neighborhood with his band, the Arkestra, where they would practice for hours on end. The ban also operated a grocery store called Pahroah's Den, which sold produce, candy, and Sun Ra records. You can see scenes from the store, along with several astonishing performances, in the 1980 documentary "A Joyful Noise." The Jazz LibrarySun Ra, a free jazz legend, claimed he was an angelSun Ra is one of jazz's most storied cult acts, with a career that spans multiple decades, dozens of hard-to-find self-released albums, and a sound that challenged even the most adventurous listeners. Ra, born Herman Blount, claimed to be from Saturn and once told an interviewer that "Star Wars" was "very accurate." The GuardianOzone protects against the sun's UV radiation and enhances the greenhouse effectIn the stratosphere, trioxygen molecules can absorb harmful ultraviolet radiation from the sun, preventing it from reaching Earth's surface, where it can harm organisms and raise surface temperatures. In the lower atmosphere, ozone acts as a greenhouse gas, trapping thermal radiation. Iowa State UniversityLack of sunlight during Arctic winters can fuel a winter slump and a circadian disconnectSunlight typically tells our brain to stop producing melatonin, a hormone that makes us sleepy, but in dark Arctic winters humans must adapt to life without much sunlight. Scientists in this video provide tips that include trying to increase the amount of light around you, even if it’s just table lamps. BBCEarly timekeeping tools included sundials, water clocks, and astrolabesAstrolabes also provided a person's latitude based on the height of the stars in the sky, thus aiding in navigation. Incense and candle clocks relied on the constant burning rate of fire to track the passage of time based on premarked locations with equal-interval spacing. History.comNed Nye instilled an interest in timekeeping and sundials in Bill NyeWhile a prisoner of war for four years during World War II, the Japanese military confiscated Ned's watch, so he built sundials to keep track of time. Ned would later research and write a book on sundials and be honored with a lifetime membership to the North American Sundial Society. EsquireThe team responsible for the first interplanetary sundials included Bill NyeWhile reviewing designs for instruments to be carried by future Mars rovers, Nye suggested adapting the function of a calibration tool, which would be used by the Spirit and Opportunity rovers to help calibrate the brightness and color of their panoramic cameras on the Martian surface. Cornell ChronicleFirst-ever image of the sun's south poleFor the first time, we have clear images of the sun's mysterious south pole. Captured in March 2025, by ESA and NASA's Solar Orbiter, this footage reveals magnetic chaos that could unlock answers about solar storms, the sun's strange 11-year cycle, and why its atmosphere is hotter than its surface. 1440Replacing the sun with a black hole would quickly collapse life on EarthA black hole of the sun's mass would only be six kilometers wide, but it would exert the same gravitational pull as the sun. This means the planets would keep their current orbits but no longer receive solar radiation. KoranosEarth’s tilt and orbit cause the sun to create a figure-eight patternThe shape—called an analemma—can be obtained by photographing the sun from the same location and time daily for a year. The Earth's eccentricity created the analemma's width, and its tilt shifts the sun's height in the sky over the seasons. TED-EdNo one's sure why it's spelled 'sundae'There are several different folktales explaining the origins of the popular ice cream dish and its curious name. One claims an enterprising pharmacy used chocolate syrup instead of soda, which was banned on Sundays. Another claims the dish's unique spelling was to avoid offending religious folks who might object to an unholy reference to the Sabbath. Taste of HomeMineral and chemical sunscreens protect differently but both guard against UV damageUVA rays age the skin, while UVB rays are more directly linked to skin cancer. Mineral sunscreens, with ingredients like zinc oxide, physically block rays, while chemical ones absorb UV and turn it into heat. Science Friday‘A Raisin in the Sun’ made history in 1959The play was the first on Broadway written by a Black woman. Lorraine Hansberry, the playwright, was 29 when it debuted at the Ethel Barrymore Theatre on March 11, 1959. HISTORYDemystifying sunscreenSunscreen is helpful all year round. Experts argue a minimum level of protection is SPF 30. There are two kinds of sunscreen: mineral (a physical barrier) and chemical (absorbs UV light). No new sunscreen ingredients have been approved in the US in decades, so foreign products are common. The Wirecutter ShowHow March Madness Selection Sunday worksMarch Madness is one of the most popular American sporting events, but most viewers aren't aware of how its 68 teams are selected for the prestigious national tournament. This official process overview breaks down how the teams are selected, seeded, and placed into the bracket. Knowing the ins and outs might not stop you from disputing the committee's selections, but at least you'll understand how they came to those decisions. NCAADisneyland’s opening day was called 'Black Sunday'A rushed, hectic construction process left the park was in bad shape for its opening, leading to a disastrous first day at the park, which employees came to call “Black Sunday.” SFGateTour the iconic Sun Studio in MemphisSun Studio is responsible for hundreds of hours of American music history, despite its rather modest setup. This tour of the one-room studio is not unlike the tour visitors take, with anecdotes about Elvis, U2, and a pious Bob Dylan, who quickly popped in to pay his respects. The A.V. ClubSun Records was responsible for some of rock 'n' roll's biggest artistsMemphis' Sun Records was one of the most important labels in American musical history, releasing pivotal records by Elvis Presley, Johnny Cash, Jerry Lee Lewis, Roy Orbison, and countless others. Sun RecordsListen to samples of 'sounds' produced by the sun's internal vibrationsSonification can turn otherwise inaudible vibrations into audible sounds, just as scientists colorize images of celestial objects taken outside the visible range into colors our eyes can interpret. This has been used to turn the vibrations within the sun detected by the Parker Solar Probe into audio clips that resemble chirping and whistling. Popular ScienceInti, the Sun God of the IncaThe Incas were polytheistic, worshiping many gods, but Inti was the most powerful one in the pantheon. He was the god of the sun and also ruled over agriculture, fertility, and war. Inti was mainly a benevolent deity, though the Inca believed that solar eclipses meant Inti wasn’t pleased. To appease him, the Inca gave sacrificial offerings including food, white llamas, and even human beings. History Cooperative'Lazy Sunday' was YouTube's first viral hitInitially aired on television, the 2005 "Saturday Night Live" digital short featuring Andy Samberg and Chris Parnell took off on YouTube, becoming one of the platform's first viral videos. The song may be a joke, but its success underscored how online video could extend the lifespan of regularly televised content. Saturday Night LiveA 1908 toy visualizes how the sun never set on the British EmpireResearchers uncovered an early-1900s children’s toy that romanticized the British Empire: a rotating world map showing where the sun shone on Britain’s far-flung territories. The interactive device also served as an advertisement for "The Children’s Encyclopedia." SlateFarmer secretly plants sunflower field for 50th anniversary with wifeKansas farmer Lee Wilson wanted to give something special to his wife of 50 years, Renee, on their golden anniversary, so he secretly planted 80 acres of sunflowers in May for an August bloom. The gift consists of roughly 1.2 million sunflowers,... logoHow the sun heats the EarthWe all know it: Without the sun's heat, the Earth would be uninhabitable. So how does it work? The sun fuses roughly 600 million tons of hydrogen every second, the energy from which bursts out into space—including toward our planet. Our atmosphere... YouTubeIs the sun aligned with Stonehenge right now?Twice a year, during the longest day and night, the sun’s path aligns ever so gently with the ruins of Stonehenge. During the summer solstice, viewers can see the sun’s rise crest the central heel stone. The winter solstice sees the sun set across the site’s altar stone. Use this interactive to tour the historic site and check its current skyscape. Stonehenge SkyscapeHow salt, sunlight, and wind drive ocean currentsThe Atlantic Meridional Overturning Circulation plays a critical role in regulating earth's climate, but is threatened by climate change. Explore the effects of temperature, density, and salinity on ocean currents in this 13-minute PBS video. YouTubeGrasp the earth's orbit around the sun with this interactiveSee why seasons exist with this interactive simulator. Toggle between different views of the earth in relation to the sun and watch as the earth's axis causes the sun to shine at different angles throughout the year, causing the weather to fluctuate and more. This simulator clarifies a process many take for granted. University of Nebraska-LincolnInside the James Webb's amazing sun shieldsThe Webb team has stationed its mammoth observatory in solar orbit—and brought its instruments below 40 kelvins (minus 233 ºC). Remarkably, most of the cooling has been done passively, by shielding the telescope from the sun and letting physics take care of the rest. IEEEWebb's sunshield enables extreme cooling for precision space observationTo avoid interference from its own heat, the telescope uses a five-layer shield to stay ultra-cold and stable, allowing its instruments to function at cryogenic temperatures. One instrument, MIRI, gets so cold it needs a helium-powered cooler to reach just 7 Kelvin, or -447°F. NASAWhat fuels the sun?The sun is our biggest source of heat and light, but how does this massive powerhouse continue to produce such amazing energy? Basically, it's a fusion reactor. At its core the sun produces all that solar energy through hydrogen fusing and converting into helium, over and over again. Learn more about the entire amazing and explosive process here. Universe TodaySee which similes appear most often in popular fictionAn analysis of 200,000 "as ___ as ___" similes from tens of thousands of fiction books finds that writers often reach for the same comparisons, with a handful of nouns like stone, cat, and hell dominating across dozens of adjectives. The PuddingUse generative AI to create a musical track from a text promptSuno, a web-based, text-to-music generator, takes a prompt—such as a music style, along with a general lyric idea—and can produce a highly polished, realistic-sounding tune in a matter of seconds. Suno