Quickie Questions - Sun - Other

Date Answered Questioner (age, location) Question Answer
May 11, 2010UMAR (PAKISTAN)HOW SOLAR AND LUNAR ECLIPSES ARE CAUSED?Basicaly, an eclipse of the Sun occurs when the Earth passes through the Moon's shadow. A lunar eclipse occurs when the moon passes through the Earth's shadow. For more details visit our web pages Solar Eclipses and Lunar Eclipses
March 24, 2010miguel (phillpines)if the sun will explode?
is it turning into a black hole
Yes, in about 5 billion more years our Sun will be in the last phase of its life as a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth.
March 5, 2010regine (philippines)what could happen on planet earth if he sun could shine anymoreThe Sun will die. But the ends of its life will happen in about 5 billion more years, when the Sun will start growing, swallow Earth (and Mercury, Venus, and Mars), and die into a small white dwarf.
February 22, 2010Nigel (UnitedKingdom)I'm told that the sun has a diameter of 870,000 miles. I'm also informed that the sun will lose 5ft off its diameter every minute. So if the sun loses 8.3 miles off its diameter each year (120ft per day, 43,800ft per year), then 870,000 / 8.3 = 104,000(ish) years before the sun is nothing. That can't be right!I have heard different versions of this calculation before, but I believe that there are arguments against it. For example, Parkinson et al. in their paper The constancy of the solar diameter over the past 250 years suggest that there has been no detectable change in the sun's diameter since at least AD 1700. Similarly, Morrison et al., in their paper Diameter of the Sun in AD 1715 supports the same idea. So, it seems to be still an open discussion among scientists.
February 3, 2010jasmine (jamaica)hello there! my question is that how long do you need to be in the sun before you get really burned?The temperature on the surface of the Sun is about 5,400 ºC (9,800 ºF), so you will get burnt instantly.
January 21, 2010Chris (Rivers state,Nigeria)Why is it that sceince has not made it to the inside of the sun?But it has! Scientists are "looking" inside the Sun through helioseismology. Helioseismology is the study of the Sun interior by studying the propagation of waves in its body (in a similar fashion to geologists learning about the interior of the Earth by studying seismic waves.)
January 13, 2010Torgen I was searching for the classification of our sun... i couldnt find it wich surprised me... im probably not looking hard enough or am to dumb so could you please answer this?The Sun is a as a G2V type star (which might be interpreted as "a 'yellow' two tenths towards 'orange' main sequence star"), a yellow dwarf and a main sequence star.
January 5, 2010ramshah (pakistan)as our sun only contain hydrogen as fuel which is converted into helium by fission reaction and it is said that earth and other planets of our our solar system are the part of sun then these scaterred pieces of sun should also contain hydrogen or helium only why it contain more elements?Although the sun and the planets all come from the same solar nebula, the evolution of a star is quite different of the evolution of planets. And keep in mind that there are other elements in our star. Elements in the Sun
Element% of total atoms% of total mass
Hydrogen91.271.0
Helium8.727.1
Oxygen0.0780.97
Carbon0.0430.40
Nitrogen0.00880.096
Silicon0.00450.099
Magnesium0.00380.076
Neon0.00350.058
Iron0.0300.014
Sulfur0.0150.040
December 23, 2009ashley (mass)what should you do during a volcanic eruptionPlease, follow FEMA (Federal Emergency Management Agency) recommendations on this page.
December 16, 2009Veronica (virginia)As the sun gets older does it get smallerActually, a star with a mass similar to our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth.
December 16, 2009Alexandria (United States)Where do solar flares originate?A solar flare is a sudden burst of electromagnetic waves and a large release of charged particles (mostly electrons) from the Sun. They erupt from the intense magnetic fields in the vicinity of active regions on the Sun's surface.
October 27, 2009abraham (africa)what is the most interesting fact about the sunThere is one that comes immediately to mind: energy from the Sun is what sustains life on Earth!
October 27, 2009Deanna (Auckland)What is the star that is bigger then the sun?The Sun is an average size star, there are many that are bigger, for example, Sirius, Pollux, Arcturus, and Rigel are all bigger than the Sun.
October 13, 2009tiffany (MD)is the sun the biggest star? people say it is and some say it isnt!No really, the sun is just an ordinary star, one of more than 100 billion stars in our galaxy. However, the Sun is in the top 10% of our galaxy's stars by mass. It seems bigger just because it is closer to us!
October 8, 2009dheepika (india,tamilnadu)Is mercury going to be destroyed because of the expand of the earth?Not really, Mercury, Venus and Earth, the so-called Interior Planets, will all be destroyed during the last phase of the Sun life, as a red giant. At this point, the Sun will have expanded to cover all the interior planets.
October 2, 2009maria (TEXAS)WHAT WILL HAPPEN IF THE SUN EXPLOTInstead of trying of imagine what would happen in such a case, let's see how the Sun will develop: A star with a mass similar to our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth. But before that, in about 1.1 Gyr (1 100 000 000 years) from today) the Sun will be 10% brighter and this extra solar energy will cause the Earth's atmosphere to dry out. Under such conditions, surface life on Earth will probably be exterminated.
October 2, 2009maria (TEXAS FORT WORTH)WHAT WILL HAPPEN IF THE SUN EXPLOTInstead of trying of imagine what would happen in such a case, let's see how the Sun will develop: A star with a mass similar to our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth. But before that, in about 1.1 Gyr (1 100 000 000 years) from today) the Sun will be 10% brighter and this extra solar energy will cause the Earth's atmosphere to dry out. Under such conditions, surface life on Earth will probably be exterminated.
September 25, 2009kavita (india)how we can differe or sense diffarant position of sun with its intensityFor higher latitudes, the Sun declination is more pronounced, and more part of the energy is reflected back to the space. In a similar way, the intensity of the Sun is more pronounced around noon, when it is vertically on top pf our head, and most of its energy reaches the surface.
September 17, 2009tokerau (NSW Austraila)why is the sun yellow?The human eyes perceive the color of a light source as depending on its intensity. A second factor is that the blue component of the sunlight is absorbed and scattered more than the red component. So, at the end, the color of our Sun is frequently described as "whitish, with a hint of faint yellow." Here you can find a detailed discussion of this topic.
September 15, 2009hastha (tamilnadu)why the sun is in red or orange color, due to scattering of light sky has these color. why do sun is like this, which energy making thisThere are many (and complicated) ways to answer your question. I will try a short abd simple one: the human eyes perceive the color of a light source as depending on its intensity. A second factor is that the blue component of the sunlight is absorbed and scattered more than the red component. So, at the end, the color of our Sun is frequently described as "whitish, with a hint of faint yellow." Here you can find a detailed discussion of this topic.
September 14, 2009Tanishqa (India)Man will float on the moon if he is not wearing special equipment.Why does a moon rover not float on the moon?Beacuse there is enough gravitational pull on the moon surface to keep the rover from floating away.
July 27, 2009Nancy (Kentucky, US)When is the next total solar eclipse for the United States?The next total solar eclipse of the Sun will occur on Monday, August 21, 2017, and will be visible from a narrow corridor through the United States.
July 16, 2009Ashley (AR)What is the Transition Region of the sun?Above the chromosphere is a very thin layer of the Sun's atmosphere about 100 km thick over which the temperature rises from 20,000 degrees Kelvin in the upper chromosphere to over 2 million degrees Kelvin in the corona. This region is called the transition region. The reasons for such dramatic rise are still not clear.
June 17, 2009MACKENZIE (UNITED STATES OF AMERICA /PA.)HOW DO YOU TAKE PICTURES OF THE SUN? ISN'T IT TO HOT!?Picture of the sun are taken from ground based observatories and from satellites. They can be obtained in different wavelenghts, including those that are not in the visible spectrum, like X-rays. The solar wind is so tenuous that the sensors are in general not affected.
April 21, 2009E (United States)How long is the Sun's rotation?The regions of the Sun near its equator rotate once every 25 days. The Sun's rotation rate decreases with increasing latitude, so that its rotation rate is slowest near its poles. At its poles the Sun rotates once every 36 days! More information on our web page Rotation of the Sun.
April 17, 2009robert (sc)we had a discussion at work about how fast sunlight reaches earth..i said seconds on nano seconds.people disagreed ..
thank you
Sunlight travels at the speed of light which is 186,282 miles per second or 299,792,458 meters per second. This means the light from the Sun takes 8.4 minutes to travel the average distance (93 million miles) to Earth.
April 17, 2009Bridget (New Zealand)Soalr wind is very how - would it burn you if you were standing on the moon?One definition scientists use for temperature is the average speed of the molecules or atoms in a gas. When the particles are moving very fast, the temperature is hot. When particles are bouncing around more slowly, the temperature is cooler. The particles in the solar wind are moving very quickly, so the temperature there is quite hot. However, the moon surface would feel quite cold to us, since the amount of particles per cubic centimeter is so low(Take a look at this picture for comparison with Earth's atmosphere.). We feel warmth when particles hit our skin and transfer heat energy to us. There are too few particles in the solar wind to transfer much energy, even though each particle is quite "hot" itself. Now, if we consider the sunlight, then yes, objects illuminated by the sunlight will become very hot, but keep in mind that radiations from the sun and solar wind are two different thing.
April 15, 2009Jezzamae (Philippines)What is ChromosphereThe chromosphere is a region of the Sun above the photosphere.It is about 2500 kilometers thick, and where bright regions known as plages, and dark features called filaments are visible.
April 15, 2009Jezzamae Flor B. Boston (Philippines)What is ChromosphereThe chromosphere is a region of the Sun above the photosphere.It is about 2500 kilometers thick, and where bright regions known as plages, and dark features called filaments are visible.
April 13, 2009alyana (Philippines)what will happened to Earth if the sun will turn into a black dwarf or a black hole?The Sun is a medium size star. It will become a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
March 23, 2009Vignesh (India)Sir, According to Big Bang the Earth was thrown off from the sun. How was the sun created? I have an hypothesis ie. according to absolute zero from something nothing is created. And my question is: Why can't from nothing something can be created which is the vice-versa of absolute zero. And can you also give me the evidences for the Big Bang?A widely accepted theory for the formation of the Sun (and planets, comets, etc) is that solar systems are formed when a cloud of gas and dust in space is disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion make waves in space which squeeze the cloud of gas and dust. Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula.
March 19, 2009shree (india tamilnadu)why is the sun so hot?The sun energy, including heat, is produced by nuclear reactions in the core, where every second, more than 4 million tonnes of matter are converted into energy.
March 17, 2009shermanIt strikes me that for the Sun to be billions of years old,that its mass would have to be much larger then it presently is. It is energy that is burning itself up. If its mass was larger,then its heat would be hotter. This in turn would make any life impossible on earth. My question is, can you say for certain how much its heat has declined in say the last 100 or 1000 years? Is there any way to know if it gets smaller with age?The Sun slowly loses mass through nuclear fusion as it is converted to energy. There is also mass lost through coronal mass ejections. In later stages of our star's life, hydrogen fusion reactions will become less efficient in the core region, and the fusion reactions will occur in a shell surrounding the core. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
March 11, 2009dhyey (gujarat/india)sun is made up of hot gases then how bubbles is formed on convection zone?Bubbles are formed when heated substance rise through a cooler medium, exapnding as it raises up to they burst. This is the typical scenario in any convective zone, including the Sun's.
March 5, 2009Arnold (Ghana)if the sun really moves, then would we on earth see the sun rise from other directions other than east?We move around the Sun in a unique plane towards the east. As viewed from the North Star Polaris, the Earth turns counter-clockwise. This defines the rising point of the Sun in our sky. The whole solar system also moves around the center of the galaxy, but this doesn't affect the solar path in our sky.
March 2, 2009tina (louisiana)how does fusion inside the sun provide an external heat source for the earthThe Sun’s core starts from the center and extends to about 25 percent of the sun's radius. Is here where gravity pulls all of the mass inward and creates a pressure so intense that it forces atoms of hydrogen to come together in nuclear fusion reactions: two atoms of hydrogen are combined to create helium-4 and energy. The helium-4 atoms are less massive than the two hydrogen atoms that started the process, and the difference in mass is converted to energy (described by Einstein's E=mc2). The energy is emitted in various forms of light (ultraviolet light, X-rays, visible light, infrared, microwaves and radio waves). Eventually this energy strikes Earth and warms the planet.
February 20, 2009bob ( ohio)What will happen if the Sun turns into a dwarf starA star with a mass similar to that of our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
February 3, 2009DonnaI read on your website that the Sun is 75% Hydrogen and 25% Helium by mass. It also said that the Hydrogen atoms fuse to form Helium. Do the percentages stay consistent or do they change since the Hydrogen is forming Helium?The composition of a star change with time, and this define the life cycle of the star. This change takes time. For example, the Sun will die in about 5 billion years, and during this time its composition will be changing very gradually.
January 26, 2009lillian (New Jersey)How hot is the sun?The temperature at Sun's surface is 5,500ºC (9,932ºF), at its Core is 14 million ºC (22.5 milliono ºF), and in Sunspots is 4,000ºC (7,232ºF).
January 22, 2009Vinay (India)Why do sunspots occour on our sun?Sunspots are caused by the Sun's magnetic field welling up to the photosphere, the Sun's visible "surface". The powerful magnetic fields around sunspots produce active regions on the Sun, which often lead to solar flares and Coronal Mass Ejections (CMEs). The solar activity of flares and CMEs are called "solar storms". More information at our webpage Sunspot.
November 6, 2008Shyam (Canada)Gravity is the thing that holds things in place like planets, so the sun is the thing that gives gravity right so,when the sun dies out and most of the planets will be destroyed but some unknown planets will survive but without the sun things{planets} won't be in place and they will or might fall down or could it?You are right. The whole solar system is linked by gravitational forces, mainly due to the huge mass of the Sun. During the final stages of the Sun life, as a red giant, the Sun will have a maximum radius beyond the Earth's current orbit. However, by the time it is an asymptotic giant branch star, the Sun will have lost roughly 30% of its present mass due to a stellar wind, so the orbits of the planets will move outward. More information here.
September 30, 2008Ayanna (Indiana, USA)How did the sun get its name?Different cultures named the sun in different ways. Here a list: Egyptian: Re, Celts: Lugh, Aztec: Tonatiuh and Huitzilopochtli, Greek: Apollo, Roman: Apollo, African: Liza, Chinese: Ten Suns, Polinesian: Maui, Japanese: Amaterasu, Sumerian: Shamash, Navajo: Tsohanoai, Inca: Inti, Inuit: Malina, Hindu: Surya, Hindu: Garuda, Mamaiuran: Kuat, Norse: Freyr. For more information on this topic, visit our web page The Sun.
September 26, 2008dennis (england)Is the sun brighter today (on average)than it was hundreds of millions of years ago when dinosaurs were alive? If so, how?A recent (2003) model developed by astrophysicists J. Sackmann and A. Boothroyd, attempts to explain observations of solar-sized stars that lose significant mass during their infancy. In this model the Sun started with between 4 and 7 percent more mass than it has today, and this extra mass means a brighter Sun (Sun’s luminosity increases with the fourth power of its mass.) From this model, the Sun lost mass and grew dimmer up to when it was about 1.0 billion years old, but after this period, the rate of mass loss will slow down significantly, and the Sun will acoordingly grow brighter. Reference: Sackmann, J., and A.I. Boothroyd, “Our Sun. A Bright Young Sun Consistent with Helioseismology and Warm Temperatures on Ancient Earth and Mars,” Astrophysical Journal, 583 (2003), pp. 1024-1039.
September 26, 2008dennis ward (england)Is the sun brighter today (on average)than it was hundreds of millions of years ago when dinosaurs were alive? If so, how?A recent (2003) model developed by astrophysicists J. Sackmann and A. Boothroyd, attempts to explain observations of solar-sized stars that lose significant mass during their infancy. In this model the Sun started with between 4 and 7 percent more mass than it has today, and this extra mass means a brighter Sun (Sun’s luminosity increases with the fourth power of its mass.) From this model, the Sun lost mass and grew dimmer up to when it was about 1.0 billion years old, but after this period, the rate of mass loss will slow down significantly, and the Sun will acoordingly grow brighter. Reference: Sackmann, J., and A.I. Boothroyd, “Our Sun. A Bright Young Sun Consistent with Helioseismology and Warm Temperatures on Ancient Earth and Mars,” Astrophysical Journal, 583 (2003), pp. 1024-1039.
September 12, 2008Min (Thiland)The stars are hotter than sun or not?The Sun IS a star. There are different stars with different characteristics, the Sun is considered an average star.
September 12, 2008Zita (Serbia)I read the question why is the sky blue... Hopefully I understood with my very beginning English:) But... I can't figure it out... then why is the Sun yellow? (if the blue light scatters the most)There are many (and complicated) ways to answer your question. I will try a short and simple one: There are several factors at play. For example, the human eyes perceive the color of a light source as depending on its intensity. A second factor is that the blue component of the sunlight is absorbed and scattered more than the red component. These factors combine to define the color of our Sun, which is frequently described as "whitish, with a hint of faint yellow." Here you can find a detailed discussion of this topic.
September 11, 2008aishath (in maldives)why is the sun so hotThe Sun energy (which is the cause of the high temperature) is produced through nuclear reactions in which nuclei collide and stick together.
September 2, 2008MADHUMITA (INDIA)How do sun's rays affect the equator?I am not sure what exactly do you want to know. Sun rays strike the equator almost perfectly vertical, carrying the maximum amount of energy due to the low reflexion that occurs at this angle.
August 18, 2008Bernard (Bernie) Goggins (Davidson, Tennessee)The earth has an atmosphere that includes hydrogen and is held in place by gravity. The 'solar winds' have swept away the moon's atmosphere. Of what are the solar winds comprised?The solar wind is a stream of charged particles called plasma, mostly comprised of electrons and protons.
July 7, 2008aaron (singapore)when is our sun going to die???It will take some time, ones 5 billion years before our Sun reach this phase.
July 2, 2008Rachied (Florida)What would happen if fusion in the solar core were to cease today?The normal process is as follows: A star with a mass similar to that of our Sun and in the last phase of its life is a red giant. Hydrogen fusion reactions have become less efficient in the core region, and the fusion reactions now occur in a shell surrounding the core. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system. I don't really know what would happen in the case you described.
June 30, 2008laura (canada)will the sun ever go super novaNot likely. A star with a mass similar to that of our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the earth. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
June 19, 2008Rainier (Alaska)In this century, what has been the solar cycle number, 9.5, 10.5, 11.5, or 12.5?Actually, we are right now in the transition between the 23rd an 24th cycles.
June 17, 2008david (florida/u.s)if the sun is a star why does it have a gravitational pull?It does! The Sun gravitational pull is what keeps the planets and other objects rotating around it!
May 8, 2008Chris (New York)When is the next to north america, Mainly New york see a full Solor EclipesOn August 01, 2008 a total eclipse of the Sun will be visible from many locations accross the Earth. The path of total eclipse begins in Canada and extends across northern Greenland, the Arctic, central Russia, Mongolia, and China. This is the closest (in time and space) I could find for New York.
May 2, 2008Kathy (Irvine)How large is the area of the photosphere?In general, Area of a Sphere = 4ðr2, and rSun = 1.4 x 106 km Then, Photosphere Area = 4ð(1.4 X 106 km)2 Photosphere Area = 2.46301 x 1013 km2
April 28, 2008audrey (Tennessee)From 1700 to 1800, the greatest number of sunspots was just over what number 10 35 100 or 150 sunspotsThe period from 1645 to 1715 is known as the Maunder Minimum, when sunspots were rare, about 50 spots appeared as opposed to the typical 40 000 to 50 000 spots normally observed in a similar period.
April 25, 2008Jayna (Kansas U.S.A.)How Long before our Sun will burn out.It will take some time, ones 5 billion years before our Sun reach this phase.
April 25, 2008Jacky (United States)In what time period was the solar activity the least?It is known as the Maunder Minimum. This is the name given to the period between 1645 and 1715, when sunspots became very rare, as this plot shows.
April 23, 2008Rebecca (mississippi/united states)will the sun bow up if it does would it become a black holeA star with a mass similar to that of our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the earth. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
April 22, 2008Caitlin (alabama)What is the EXACT climate of the sun?The visible solar atmosphere consists of three regions: the photosphere, the chromosphere, and the solar corona. The solar atmosphere is so hot that the gas is primarily in a plasma state: electrons are no longer bound to atomic nuclei, and the gas is made up of charged particles (mostly protons and electrons). In this charged state, the solar atmosphere is greatly influenced by the strong solar magnetic fields that thread through it. These magnetic fields, and the outer solar atmosphere (the corona) extend out into interplanetary space as part of the solar wind. There are other solar phenomena, the Sunspots are dark, planet-sized regions that appear on the "surface" of the Sun and follow an 11-year cycle. The Coronal Mass Ejections (CMEs) are explosions in the Sun's corona that spew out solar particles and that can be dangerous when they hit the Earth, Solar Flares are essentially huge explosions on the Sun that happen when intense magnetic fields on the Sun become too tangled.
April 9, 2008Natisha (canada,ontario)Will the sun ever crash into mars?A star with a mass similar to that of our Sun and in the last phase of its life is a red giant. At this stage, the Sun would have grown up to beyond the Earth's orbit.
April 3, 2008Wee (Singapoore)Why is the sun a star?A star is a celestial body of hot gases that radiates energy derived from thermonuclear reactions in the interior. This definition corresponds to our Sun.
April 3, 2008Wee Winnie (Singapoore)Why is the sun a star?A star is a celestial body of hot gases that radiates energy derived from thermonuclear reactions in the interior. This definition corresponds to our Sun.
March 28, 2008rosette (davao, philippines)in what part of the earth receives the hottest rays from the sun?There are no differences among the sun rays received on Earth, what change is the inclination of the rays: more perpendicular rays, which are at equatorial latitudes, reach deeper into the atmosphere and surface, and deposit more energy (heat) on our planet.
March 28, 2008jimmyWhere can I find a detailed listing of solar activity for prior years?The information you require can be found at the Solar Data Services of the NOAA-National Geophysical Data Center (NGDC).
March 27, 2008Teresa (Georgia USA)I am having a solar product manufactured and I was asked what the degree of the sun is for my country so they will know where to put the solar panel. Can you tell me what the degree of the sun is in Georgia USA. The solar panel is 2v if that information is needed.I would assume that the value your are looking for is the inclination of the Sun at your location. This link covers this topic and offers, at the end, a couple of simple equations. You just have to plug in your latitude to obtain the desired value.
March 25, 2008 what is a solar flare?Solar flares occur when intense magnetic fields on the Sun become too tangled. Like a rubber band that snaps when it is twisted too far, the tangled magnetic fields release energy when they "snap". For more information visit our page Solar Flares
March 25, 2008Aleyda (Florida)"What causes the apparent changes in the sun’s position during the year?"There are two factors that affect the apparent position of the Sun in the sky. The rotation of our planet is responsible for days and night, and the tilt of Earth’s axis combined with the translation is the cause of the change of Sun inclination along the year.
March 12, 2008Sowmya (India)If you stand in the same location at noon everyday for a year and mark the position of the sun, what shape would it trace out?The tip of the shadow will form a helix shape. This is due to the fact that the Earth’s axis is tiled 23.5° in relation to the plane of its orbit around the Sun, and the path of orbit is an ellipse.
March 11, 2008taylor (indiana)Can you describe solar flares.A solar flare is a sudden and intense variation in the Sun brightness. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time! More information on NASA-Solar Flare.
March 11, 2008vijaya (india)when observing sunset from a fixed point like staying at same place as a fixed pillar, and watching the sun set,and again observing setting at a mountain place ,why the sun doen't set at the same place every day.either it will set little right ,or left.why from earth the viewing of setting different over the period of time, why from earth while we watching the setting ,the sun will set very fastly.Due to the relative motion of our planet respect to Sun, the sunset does change with the days. The U.S. Naval Observatory's webpage Complete Sun and Moon Data for One Day will return the times of sunrise, sunset, moonrise, moonset, transits of the Sun and Moon, and the beginning and end of civil twilight, along with information on the Moon's phase by specifying the date and location.
March 10, 2008justice (PENNSYLVANYA)How many pictures have been tacken of the sun?Many pictures!!! As a matter of fact, the Sun is continuously being photografied (visit, for example, the NOAA-Space Weather Prediction Center or NASA).
March 3, 2008Laurie (Ca/USA)how long does it take for the Sun's gamma rays to reach earth?Gamma rays are a form of electromagnetic radiation, which travels at the speed of light. So, it takes about 8 minutes to reach Earth from the Sun.
February 28, 2008anai (california)what is the temperature of the sun?The Sun's outer visible layer (the photosphere) has a temperature of 6000°C (11000°F).
February 15, 2008tyler (G.A.\U.S.)When is next solar eclipse and will I live to see it?On Friday, 2008 August 01, a total eclipse of the Sun is visible from within a narrow corridor that traverses half the Earth. For more information visit NASA-Eclipse.
February 13, 2008stefanie (canada)what are the four dimensions of the sun?????Scientists usually assume the 4th dimension to be time (in this case, how the Sun changes over time).
February 7, 2008Vibhav (UP/India)Sun emits all kinds of radiations like gamma rays or X-rays but we say that ozone layer absorb only the UV rays. Although the other rays are more harmful and they are not being absorbed by O3 layer, where do they go? Do they not reach earth, if so why?Much of the harmful solar radiation is deflected by the magnetosphere, the natural shield of our planet. The part the reaches the atmosphere is mostly absorbed in a region known as the ionosphere. Some radiation still reaches the surface, but is not as dangerous as, for example, a long day of sun bathing.
February 6, 2008(USA)When and where will the solar eclipes be?The most comprehensive web page for eclipses is NASA-Eclipse Home Page. There you will find tables of eclipses, pictures, and general information related with this topic.
February 3, 2008Sandeep (India)After sun becoming a black hole,from where we will get light source(Can Arcturus make it possible)?A star with a mass similar to that of our Sun and in the last phase of its life is a red giant. At this point of its life, the Sun will have expanded to cover all the interior planets, including the earth, because hydrogen fusion reactions have become less efficient in the core region, and the fusion reactions now occur in a shell surrounding the core. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
January 25, 2008Ganesh. (India.)When the distance between earth & moon is small,total solar eclipse occurs.When the distance is large,annular eclipse occurs.what is the reason for the variation in the distance?The reason for the different distances between the Earth and the Moon is that the Moon, like the planets and other satellites, has an eliptical orbit. Our page Solar Eclipse on May 31, 2003 offers more informaton on this topic.
January 12, 2008Akanksha (India)What is the another name for the sunspots noticed on the surface of the sun?Two of the most impressive phenomenon of our star, solar flares and coronal mass ejections, originate in magnetically active regions around sunspot groupings. Similar phenomena observed on other stars are called starspots.
January 8, 2008Madison (Tennessee)What is the largest explosion in the solar system produced by the sun called?One of the most impressive events are solar flares. Flares occur when intense magnetic fields on the Sun become too tangled, releasing energy when they "snap". For more information visit our page Solar Flares
January 4, 2008 How we can tell the internal and outer temperature of the sun?There are a couple of ways in which the temperature is determined. We know the amount of solar energy received on Earth per unit time over a unit area facing the Sun. We also know the distance between our planet and the Sun. With this information it is possible to calculate the total energy being emitted by the Sun. The total energy emitted per unit time per unit area is related to temperature in a known way. This can be used to find the Surface temperature of the Sun. To estimate the temperature of the interior of the Sun we use the fact that the Sun is a stable body (our own existence support this), and that gravity holds the Sun together, which implies that the gas pressure must be enough to balance the gravitational force. The relation between gas pressure and temperature is known, and is then used to calculate the core temperature.
December 20, 2007calisha (texas)What are solar flaresA solar flare occurs when magnetic energy that has accumulated in the solar atmosphere is suddenly released. A sunspot is a region on the photosphere of the Sun with a lower temperature than its surroundings and intense magnetic activity. Solar wind is a stream of charged particles (plasma) flowing from the upper atmosphere of the Sun.
October 15, 2007vibhav (u.p./ India)Sun emits all sorts of electromagnetic radiation like Gamma rays, X-rays,etc.But why only UV rays do harm to life on earth, why not the others, being more energitic, do?Not only UV rays are harmful, X-rays, for example, could be very damaging.
September 19, 2007Amit (India)If Sun is a star then it is possible that one day sun is also fall on earth is it possible and what is the average age of starIn about 5 billion years, the hydrogen in the center of the Sun will start to run out, the helium will get squeezed, and this will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
September 11, 2007rhi (N.z)how old is the sun?The Sun's current main sequence age is thought to be about 4.5 billion years.
August 17, 2007Rhiannon (New Zealand)how long do the sun's rays take to get from earth to the sun?If your question is how long do sun's rays take to get to our planet, then the aswer is about 8 minutes.
August 17, 2007Douglas (United States)"does the sun change in size (get smaller)? I read somewhere that it looses 5ft. an hour in its diameter could this be true?"All stars change size over their lifetimes, but the sun is currently very stable and about 1.4 million kilometers (changes in the sun's apparent size are due to he change of Earth's distance from the Sun).
July 26, 2007Enya (Ohio)A. What is most likely the ultimate fate of the planet Earth?
B. About how long to astronomers think it will be until the Earth is destroyed?
In about 5 billion years, the hydrogen in the center of the Sun will start to run out, the helium will get squeezed, and this will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
July 25, 2007courtney (NSW Australia)When the sun dies where will we go?That is a premature question to ask. At the rate at which the Sun is currently losing mass, it would take over 1 trillion years (this is 100 times longer than the age of the Universe) for the Sun to disappear.
July 20, 2007Yudhaveer (Rajasthan, India)Where is the hottest blue flame present in the sun and whats the impact of it on the temperature of sun?I am not sure what you mean by "hottest blue flame present in the sun". These are the typical temperatures ofour star: Temperature at surface: 5,500 oC (9,932 oF) Temperature at Core: 14 million oC (22.5 million oF) Temperature of Sunspots: 4,000 oC (7,232 oF).
July 19, 2007charles the speed of the heavenly bodiesThe Sun orbits the galaxy at about 220 km/s (492 126 mph), taking nearly 220 000 000 years to complete one full orbit (known as galactic year). Our Earth orbits the Sun at about 29.85 km/s (66 780 mph). The Moon orbits earth at a maximum orbital speed of 1.082 km/s (2420 mph).
July 18, 2007khushboo (india )After millions of years i have heard that sun will become black & will eat our every panets .why is it so?The Sun is about halfway through its main-sequence evolution, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than 4 million tons of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation; at this rate, the Sun will have so far converted around 100 Earth-masses of matter into energy. The Sun will spend a total of approximately 10 billion years as a main sequence star. A star with a mass similar to that of our Sun and in the last phase of its life is a red giant. Hydrogen fusion reactions have become less efficient in the core region, and the fusion reactions now occur in a shell surrounding the core. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
July 18, 2007MANIK (america)How long will sun give light to earth.The Sun is about halfway through its main-sequence evolution, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than 4 million tonnes of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation; at this rate, the Sun will have so far converted around 100 Earth-masses of matter into energy. The Sun will spend a total of approximately 10 billion years as a main sequence star. A star with a mass similar to that of our Sun and in the last phase of its life is a red giant. Hydrogen fusion reactions have become less efficient in the core region, and the fusion reactions now occur in a shell surrounding the core. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
July 17, 2007jade (london)how does the position of the sun change throught the dayThe Sun, as we see it on our sky, comes out the East and runs toward the West, where it gets out of view at the end of the day...
July 11, 2007ancil (Auckland, NewZealand)From where is the sun getting more helium or hydrogen if it keeps burning it?They are the two most common elements on the Sun: Hydrogen (73.4 % of the solar mass) and Helium (25.0 % of the solar mass). There are also traces of heavier elements, but they are found in very low concentrations.
July 11, 2007PULKIT (INDIA,DELHI)How can Andromedia glaxie steel our Milky Way's
sun?
Our Sun is only one of billions of stars in our galaxy. There is no particular reason for Andromeda to steal our sun.
July 5, 2007Michael (NJ,US)what was the period from 1645 to 1715 calledDuring this period, from 1645 to 1715,the sunspots were amost non-existent. It is knwon as the Maunder Minimum.
July 5, 2007Veronica (Pennsylvania/USA)when will the sun explode?In about 5 billion years, the hydrogen in the center of the Sun will start to run out. The helium will get squeezed. This will speed up the hydrogen burning. Our star will slowly puff into a red giant. It will eat all of the inner planets, even the Earth. For a more complete description of this process, visit our web page The Fate of the Sun.
June 28, 2007jakewill the sun explode and destroy us?In about 5 billion years, the hydrogen in the center of the Sun will start to run out, the helium will get squeezed, and this will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
June 28, 2007ryan (western australia)what is the suns surface gravityThe gravity of the Sun at the photosphere is g (Sun) = 274 m/s2.
May 30, 2007Aheli (India)What is the colour of the sun When we see it from space?A quick answer to this question, without going in to the discussion of the nature of the light and the physiology and how your eyes and brain perceive that light, is that the sun is a "yellow" star by definition, regardless of where you are, but when looking at it in space it would be so bright that it would appear white.
May 11, 2007Billie (England)I realize the sun always moves from East to West. So if you face the sun in England it appears to move from the left to the right relative to the body. If you are in Australia, and you are facing the sun, would it appear to move from right to left? Thank you!Yes, it is still moving from W to E, but, facing the Sun, it appears to be from right to left.
May 2, 2007mackemley (florida)how long does it take the solar wind to travel from th sun to the earthThe solar wind travels at velocities, between 300 and 800 km/sec. In particular, the solar wind speed is at a high (800 km/s) over coronal holes and at a low (300 km/s) over streamers. Using the formula t = s/v (time = distance divided by speed) we obtain a minimum of 4 days for the solar wind to arrive at our planet. A real-time display of the solar wind speed can be seen at the Space Environment Center.
April 13, 2007uma (India)why sun is called g2 star?The classification of stars is roughly based in the following table: Type Mass Temp Radius Luminosity (Sun=1) ------------------------------------------- O 60.0 50,000 15.0 1,400,000 B 18.0 28,000 7.0 20,000 A 3.2 10,000 2.5 80 F 1.7 7,400 1.3 6 G 1.1 6,000 1.1 1.2 K 0.8 4,900 0.9 0.4 M 0.3 3,000 0.4 0.04 ------------------------------------------- Our Sun characteristics put it on the G2 classification.
April 4, 2007Adrian Cheyenne Waller (Texas,US)Will the sun collide with Earth or any other planets?In about 5 billion years, the hydrogen in the center of the Sun will start to run out, the helium will get squeezed, and this will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
March 31, 2007Jasmine ()what chemicals make up the sun.The two most common elements on the Sun are Hydrogen (73.4 % of the solar mass) and Helium (25.0 % of the solar mass). There are also traces of heavier elements, but they are found in very low concentrations.
March 28, 2007blake (US)what is the average size of a starOur Sun, considered an average star, has a diameter of 1.4 million km (870,000 miles), and a mass that is 330,000 x Earth's (Earth's mass = 5.98 x 1024 kilograms).
March 27, 2007Saalihah (South Africa)What is the importance of the sun. What does it do for us. Eg. provides warmthIn very few words: without the heat and light of the sun, life as we know it could not exist on Earth. The solar energy is used by plants in the process of photosynthesis, and its energy is in this way stored in food and fossil fuels. The Sun energy also sets up the convection currents (energy of moving air), and is the source of energy for the water cycle.
March 26, 2007Mehul (Bangalore,India)I am curious to know as to how does the intensity of the Sun vary throughout the day?
At dawn & dusk we can directly look at the Sun,but say at noon its not possible as the intenisty is very high!
Also the distance between the Sun & Earth doesnt change much in a day time,isn't it?		It is never safe to look directly to the Sun! One of the most widely available filters for safe solar viewing is a number 14 welder's glass, available through welding supply outlets. More recently, aluminized mylar has become a popular, inexpensive alternative. Mylar can easily be cut with scissors and adapted to any kind of box or viewing device (adapted from NASA). The intensity of the Sun that reach the Earth surface varies as a function of the angle of the Sun over the horizon. At dawn or dusk, the energy of the Sun has to travel through a wider atmosphere, while at noon, because its (almost) perpendicular position, it travels through a very narrow atmosphere.
March 21, 2007Chahat (India, Punjab)If there are stars which are 100 times bigger than the sun why can't we see them as big as the sun?Our Sun is only around 150 000 000 km from our planet, while the closest star, Proxima Centauri, is about 4.2 light years (39 734 219 300 000 kilometers) from our planet, this is 264 894 times farther that our Sun.
March 12, 2007jaida (california)will the sun ever explode and make a whole bunch of little suns ???In about 5 billion years, the hydrogen in the center of the Sun will start to run out, the helium will get squeezed, and this will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
March 12, 2007cody tell about the sun and the stuff you use to look at it with?You can find a good del of information about the Sun in our web page The Sun. There are many ways to study the Sun. Since the beginning of the civilization, humans have studied the Sun. There are very old records that show how different civilizations observed the dark spots on the surface of the Sun. Today scientists use optical instruments that work with different wavelengths. They use the spectroscope to learn about the composition of the sun based on its spectrum. Satellites are always looking at the Sun and the solar wind, etc.
February 25, 2007rachel (usa)will the sun ever blow up?In about 5 billion years, the hydrogen in the center of the Sun will start to run out, the helium will get squeezed, and this will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
February 25, 2007shamalla (N.Y.)what make the sun shineThe Sun produces energy through nuclear reactions in which nuclei collide and stick together.
February 13, 2007Samuel (England)How long will the sun give energy to the earth?In about 5 billion years, the hydrogen in the center of the Sun will start to run out. The helium will get squeezed. This will speed up the hydrogen burning. Our star will slowly puff into a red giant and will eventually eat all of the inner planets, even the Earth.
February 8, 2007Hadi (Dubai)what is the biggest star in the solar system?There is just one star in our Solar System: the Sun.
January 24, 2007kia (ohio)how big is our sun compared to the rest of our solar system?The diameter of the Sun is 1.4 million km, approximately 110 times of the Earth's, and its mass is around 330 000 times of the Earth’s mass. Our Table of Planets will help you to compare the Sun with the rest of the planets.
January 5, 2007Kalene (Alabama)Will the sun ever stop Glowing, Will there not be a sun in a point of time? KaleneScientists have calculated that the Sun has been active for about 4.6 billion years, and has enough fuel for another five billion years. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. Later on it will suddenly collapse into a white dwarf. It may take a trillion years to cool off completely.
January 3, 2007Yves (Ghana)Is it true that the sun will someday loose fuel and die as all stars do? If yes please explain how life will exists without the sun.Or perhaps will that be on the judgement day as some people beleive? I am confused.:-(Scientists have calculated that the Sun has been active for about 4.6 billion years, and has enough fuel for another five billion years. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. Later on it will suddenly collapse into a white dwarf. It may take a trillion years to cool off completely.
December 27, 2006 how does the sun creat its energyThe sun's energy comes from nuclear fusion in the sun's central core. Fusion is the collision of atoms at high temperature and speed causing them to become one atom and release energy.
December 27, 2006tysierra (miss)what is the solar cycle number for this centuryThis current Solar Cycle is the 23rd.
December 27, 2006oamng (pakistan)is ther any life on any palnetEstimates range from 17 thousand to 50 million years for the "photon travel time" from the Sun's core to the photosphere. See this page and the "Core" section of Wikipedia's page on the Sun for details and references (http://en.wikipedia.org/wiki/Sun)
December 27, 2006RIdge (Florida)Where does a nebula come from?Scientists believe that solar systems are formed when a cloud of gas and dust in space is disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion make waves in space which squeeze the cloud of gas and dust. Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula.
December 9, 2006OMEN (south africa)is it posible for the sun to explode againIn about 5 billion years, the hydrogen in the center of the Sun will start to run out. The helium will get squeezed. This will speed up the hydrogen burning. Our star will slowly puff into a red giant. It will eat all of the inner planets, even the Earth. As the helium gets squeezed, it will soon get hot enough to burn into carbon. At the same time, the carbon can also join helium to form oxygen. The Sun is not very big compared to some stars. It will never get hot enough in the center to burn carbon and oxygen. These elements will collect in the center of the star. Later it will shed most of its outer layers, creating a planetary nebula, and reveal a hot white dwarf star. Extracted from our web page The Fate of the Sun
December 9, 2006jonathon (IOWA/USA)What are the two main gasses that burn on the sun?The two most common elements on the Sun are Hydrogen (73.4 % of the solar mass) and Helium (25.0 % of the solar mass). There are also traces of heavier elements, but they are found in very low concentrations.
December 9, 2006Sean (AZ in the US)Why does the sun still burn if there is no oxigyn in space?The production of energy on the Sun doesn’t require oxygen because it happens through nuclear reactions in which nuclei collide and stick together.
November 30, 2006Aen (phil.)when do solar flares occurFlares occur when intense magnetic fields on the Sun become too tangled. Like a rubber band that snaps when it is twisted too far, the tangled magnetic fields release energy when they "snap". For more information visit our page Solar Flares
November 27, 2006amanda what is the estimated age of the sun? please hurry {lol} i have a huge science test tommorrow and need help!The estimated age of the Sun is about 4.5 billion years. For more interesting facts about our star, visit this page.
November 20, 2006Logan (Virginia,USA)How many years marks the reversal of the Sun's magnetic field?The main periodicity in the Sun's activity is the 11-year solar cycle. At the beginning of a cycle, during the minimum, the solar magnetic field resembles a dipole aligned with Sun's rotation axis (very similar to Earth’s magnetic field). During the following 5-6 years towards the maximum, this configuration is completely changed, leaving the Sun in a disorganized magnetic state. During the latter part of the cycle the dipole field is restored with an opposite orientation than the old one. This creates a 22-year cycle for the Sun.
October 23, 2006Celeste (South Africa)What gases are found on the sun?The two most common elements on the Sun are Hydrogen (73.4 % of the solar mass) and Helium (25.0 % of the solar mass). There are also traces of heavier elements, but they are found in very low concentrations.
November 22, 2002Nicholas (Michigan, USA)How many 'Earths' would be required to equal the volume of the sun ?Since the volume of the Sun is 1.43603^18 km^3 and the volume of the Earth is 1.08087^12 km^3 , 1328578.6 'Earths' would equal the volume of the Sun.

September 23, 2002Tony (Ohio, USA)What is the size of the Sun in metric units and English units?Check out our Sun Statistics page!

August 8, 2001Stephen (New Jersey, USA)I would like to know if the sun is getting hotter or colder?The Sun is pretty constant now, but eventually it will get cooler. This will happen when the hydrogen in its core is used up, and the standard H+H=>He fusion reactions stop. When this occurs, the outer layers of the Sun will cool and expand, and the Sun will become a red giant. If you're interested, check out our tour explaining the life of a star.
August 3, 2001Neil (England)What percentage of our solar system does our Sun occupy?Your question is a good one, and tough to answer. Scientists aren't sure just how big our solar system really is, so we can't really say how much the Sun occupies by percentage. Estimates say that the solar system, as defined by the edge of the heliopause (the region in which the Sun's influence can be felt), might be as large as 200 AU in diameter (1 AU is the distance between the Earth and the Sun, so 200 AU would be 18.6 billion miles). Using the current estimate for the Sun's radius at 435,000 miles, one can then calculate that the Sun only takes up roughly one ten-trillionth (1 part out of 10,000,000,000,000) of the volume of the solar system.
July 25, 2001Lisa (California, USA)Is there any chance of the Sun accidentally being moved and it colliding with the Earth?The Sun is actually moving quite fast through the galaxy (the whole solar system is revolving around the center of the Milky Way), but the distance between the Sun and the Earth stays pretty much the same (around 93 million miles). For this distance to change, something would have to happen to either knock the Earth into a closer orbit (like a collision with something really huge, probably bigger than any comet or asteroid we know of), or something would have to happen to the Sun to change its gravitational pull on the Earth. Either of these ideas is pretty far-fetched, so a Sun-Earth collision isn't something to worry about.
July 13, 2001PaulaWhat vitamin does the sun produce?When sunlight strikes us, Vitamin D is produced naturally within our bodies.
January 3, 2001Samarantha (Illinois, USA)What are the chances of having an eclipse of the sun on Christmas in the year 2000? My mother thinks it may be prophetic somehow and I would like to know the odds of such a phenomenon occuring. Thank you for your time.Well, there actually was a solar eclipse on Christmas Day 2000 for much of North America. Unfortunately, it was really cloudy that day, so much of the country didn't see it (I was in Michigan at the time and couldn't even see it get a little darker because it was already so cloudy and dark!). People through the ages have taken eclipses and other astronomical phenomenon to be indicators of important happenings!
October 12, 2000Syafiq (Selangor)What's the meaning of penumbra?The penumbra refers to part of the shadow cast during an eclipse. Penumbras occur in both solar and lunar eclipses. Be sure to click on the pictures on those pages for a graphical explanation!
September 26, 2000Mickala (Ohio, USA)What does the Sun look like up close from satellite pictures?Here are some safe ways to look at the Sun (don't ever look directly at the Sun with your own eyes!).
September 6, 2000John (New Mexico, USA)What is the name of the Sun's outer atmosphere?The outer layer of the Sun's atmosphere is the corona.
July 12, 2000Anna (Michigan, USA )Do x-rays come from the sun?Yup, x-rays come from the Sun all the time. X-rays from the Sun are emitted mainly from the corona layer of the Sun. When there is a solar flare, there could be a bigger amount of x-rays coming towards the Earth. And it only takes x-rays about 8 minutes to reach Earth!
June 19, 2000Kayla (Connecticut, USA )Is the sun a star or a planet?The Sun is a star. And it's actually a fairly average star in age and in size!

June 16, 2000Ryan (Texas, USA )What does a magnetosphere do ?A magnetosphere protects a planet from potentially harmful particles coming from the Sun.
December 3, 1999Jenne what is the inclination of the axis of the sun?The Sun's axis is inclined at an angle of seven degrees from perpendicular to the ecliptic.
October 20, 1999Anwar (California, USA)Can you please help me with this question? I am having a hard time finding it. What percent of Sun's total energy reaches our earth, and how much is it in watts?I bet this page will help.
October 11, 1999Samantha (Illinois, USA)How many earths would fit inside the sun?Take a look at this page!
October 11, 1999Andrew (Wisconsin, USA)How hot is the sun?Why don't you take a look at this page!
October 11, 1999Melissa (Maine, USA)At what rate(in watts) is wnergy produced by the sun?The surface of the Sun puts out about 64,000,000 watts per meter squared. That's a lot of energy!
September 28, 1999Vincent (Georgia, USA)What is the scientific name of the sun??? I have heard that it is 'Tau Ceti' and wish to verify the accuracy of this statement. Thanks!Tau Ceti is actually a different star, in the constellation of Cetus. It is 11.8 lightyears from the Sun. The Latin name for the Sun is 'Sol'.
September 28, 1999Robert (California, USA)How did the Sun get its English name? What does the word 'Sun' mean?The word 'Sun' is of germanic origin, with its root going back to an ancient proto-Indo-European language. The word is now used as defining the object 'Sun', or other 'suns' like our own.
May 27, 1999Chris (New York, USA)How strong is moonlight compared to sunlight?The Moon has an albedo of 7. This means that it reflects 7% of the Sun's light. Since the Moon's light is only a reflection of the Sun's, its maximum brightness is 7% that of the Sun's.
March 3, 1999Brandy (Pennsylvania, USA)What links can I go to to receive info on solar energy?Try looking at our Solar News and Discovery page for more information about the Sun. It includes my favorite source for solar energy information.
February 5, 1999Drew (Oregon, USA)My mom told me that she read that the sun is actually a green color. She said this is related to the quantity of light being absorbed by plants, and then reflected at the nearly the same frequency (she is helping me write this). I know that the sun sends all colors of light, but what is its color mostly? Is it really greenish? Do Rayleigh waves (blue) plus sunlight (yellow) combine to make green? If it is true, I am going to be doing extra chores this whole year.The Earth's atmosphere is not thick enough to really affect the color of the Sun. So, if you were to look directly at the Sun (don't ever do this!), you would see that it really is actually yellow. So, I guess you win, Drew!
October 7, 1998Laura(Pennsylvania, USA)What machines and equipment do you use to figure out facts about the sun?Some of the most effective machines used to find out about the Sun are satellites that are out in space. Take a look at our Ulysses section and pages about its instru ments. Or take a look at the ACE satellite and its instruments.
July 15, 1998Jim (North Carolina, USA)How was the age of the Sun determined? How about the Planets in general?The solar system is thought to be about 4.6 billion years old. Here's how scientists get that number.
April 16, 1998Freddy (New York, U.S.A.) How was it proven that the Sun is the center of our Universe?Well, as far as I've heard, the Sun is not at the center of the universe. In fact, the Sun is not even the center of our Milky Way galaxy. The center of the Milky Way is found by looking in the direction of the constellation Sagittarius. Sagittarius is a summer constellation in the northern hemisphere, so you should be able to look that way soon!
January 20, 1998Patrick (Michigan, USA)Why is the sun called the sun?Centuries ago (when people spoke Latin!) people called the Sun, 'sol'. Around the 12th century, the Latin word 'sol' got transformed into the Old English word 'sunna'. Then from there 'sunna' became 'sunne' in Middle English. Modern English shortened 'sunne' to sun. So that's why we call the sun the Sun!

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