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SunThe sun is the closest star to Earth, located at an average distance of 150 million kilometers (93,000,000 miles). It contains 99.8% of the solar system's mass 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 more than 10,000 times the energy 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 observable from Earth. Besides light, the sun 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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While the sun, moon, and stars rise and set from east to west due to Earth's rotation, the moon's eastward revolution around the Earth causes its shadow to move from west to east during a solar eclipse. minutephysicsIf the sun disappeared, we would not know about it for 8 minutes and 20 seconds, at which point the Earth would suddenly move in a straight line on its way out of the solar system. VsauceThe sun will become a red giant after it exhausts the hydrogen fuel in its core, causing gravity to collapse the core and heat it enough for the surrounding hydrogen shell to ignite, releasing enough energy to cause the star to swell. Quanta MagazineThe 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 ExploresWhile the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system. Be SmartLearn 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 ResearchAn 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 GeographicSunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil. 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 GeographicSolar eclipses block the sun enough to enable scientists to observe its faint outer atmosphere, or corona, whose spectrum led to the discovery of helium over a decade before it was identified 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 sun and Earth's liquid outer core help create the northern and southern lightsEarth's magnetosphere, generated by the movement of molten iron deep within the planet, consists of a magnetic field that deflects charged particles north and south. Some of the particles released by the sun in the solar wind become trapped in this field and are propelled toward the poles, where they produce auroras through collisions with atmospheric particles. Be SmartThe 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 GuardianThe Sundance Film Festival is named after a Robert Redford characterRedford purchased a plot of land in Utah in 1969, calling it Sundance Mountain Resort, a nod to his role in the film "Butch Cassidy and the Sundance Kid." Soon after purchasing the land, he began hosting workshops to develop young artists. The Sundance Film Festival (originally called the Utah/US Film Festival) was first held in 1978 and was intended to draw attention to independent cinema. HISTORYOzone 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 disconnect. 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.comThe sun emits a continuous stream of plasma known as the solar windComposed of charged particles—electrons and ions—the solar wind is deflected around the Earth by the planet's magnetic field. More powerful solar storms, known as coronal mass ejections, are short-lived but produce huge clouds of plasma that disrupt technology upon reaching Earth. The ConversationPhotochemical smog forms when sunlight reacts with car and industrial emissionsThe hazy phenomenon's name is a combination of "smoke" and "fog" and is composed of chemical pollutants that can cause eye irritation, lung damage and harm to crops. Smog buildup is more common in cities with sunny climates, minimal wind and surrounding mountains that trap these chemicals. TED-EdThe UV index measures the sun's ultraviolet radiation risk on a scale of 1 to 11+The tool takes into account geographical location, time, elevation, and cloud coverage to help individuals plan their daily activities around the sun's peak UV exposure times, which occur from 10:00 am to 4:00 pm. A value at or above 6 requires sunscreen (SPF 15+), shelter, or UPF clothing Popular ScienceMartian skies and sunsets resembled Earth's hundreds of millions of years agoEvidence suggests that Mars has had a thicker atmosphere, which included greenhouse gases, and a magnetic field in its past, resembling Earth's current composition. After losing its magnetic field—the protection from solar wind—the atmosphere and its associated atmospheric phenomena gradually disappeared. Be Smart'Some painters transform the sun into a yellow spot, others transform a yellow spot into the sun.'- Legendary artist Picasso (1881–1973) BrainyQuoteFirst-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. 1440Ancient sunken plates may influence mantle convection and surface motionResearch suggests sunken tectonic plates can collide, assemble, and break apart to form structures called large low-velocity provinces. LLVPs can significantly enrich rising magma plumes with elements commonly seen on Earth’s surface. PBS EonsReplacing 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. KoranosMineral and chemical sunscreens protect differently, but both guard against UV damage.UVA 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. NCAAThe Earth orbits the sun within the Orion Spur arm of the Milky Way galaxyThe solar system is roughly halfway between the galaxy's outer rim and its center, which is located about 25,000 light years away. The Milky Way is itself one of hundreds of thousands of galaxies in the Virgo Supercluster. BBC Sky at Night MagazineTour 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 RecordsEnough sunlight hits Earth in just 90 minutes to power the planet for an entire yearDespite this, in 2023, only 5.1% of electricity in the US came from solar energy. Solar panel technology has nonetheless made significant advancements since the 19th century, largely due to NASA's efforts in the space race. 1440Inti, 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 LiveWatch the sunset at Stonehenge during the 2025 Summer SolsticeEach year, tens of thousands gathered at Stonehenge to witness the sun’s alignment with the stones during the solstice. Watch a replay of a lifestream of the event from 2025. English HeritageSolar power is converting the sun's energy into thermal or electrical energySolar energy is the most abundant renewable energy resource. It can be captured in photovoltaic cells to generate electricity, solar heating and cooling technologies for temperature control, and concentrated solar power to drive steam turbines. Solar Energy Industries AssociationFarmer 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. YouTubeUnlike solar panels, which convert sunlight directly into electricity, concentrated solar power systems focus sunlight to heat a material that boils water, which then drives a turbine-generator to produce electricity.While common solar panels use sunlight to generate electricity, concentrating solar power takes a different approach to utility-scale power generation. Thousands of mirrors reflect sunlight onto a central receiver, which heats up so much that it boils water, creates steam, and drives a turbine (like conventional power plants). Take a peek inside one of the country's largest CSP plants in this video. Physics GirlInside 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 Today
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