What is the actual size of the sun?
354168
the "smart kid" is incorrect about the size of the sun.  It is only 109 times larger than the planet earth.  The Sun's diameter is 864,938 miles (1,391,980 km). This is almost 10 times larger than the planet Jupiter and about 109 times as big as the Earth. The volume of the Sun is 1,299,400 times bigger than the volume of the Earth; about 1,300,000 Earths could fit inside the Sun.
909777
The brightness and apparent size of the Sun would be inversely proportional to the square of one's distance from it.  If you moved to 2000 miles from the Sun, about 1/50,000 the Earth's distance from it, the Sun would appear 2.5 billion times larger (in apparent area, but only 50,000 times wider) and brighter.  Hubble can't be moved close to the Sun because Hubble orbits the Earth at a fixed orbital radius.  In addition, Hubble and most other astronomical observation tools cannot be pointed at the Sun, because the light output would overwhelm their sensors.  Only a very few devices have been designed to observe the Sun.
1041670
The distance to the sun can be computed by a variety of techniques.  Trigonometry and parallax measurements were used by ancient greek and arab astronomers to come up with pretty good estimates for the distances to the sun, moon, and other planets.\n\nThe sun's diameter at its equator is about 865,000 miles, and the mean distance from the earth to the sun is about 93 million miles.\n\nThe moon's diameter at its equator is about 2,160 miles, and the mean distance from the earth to the moon is about 238,900 miles.\n\nThe ratio of the diameters is 865000 / 2160 or about 400.  The ratio of distances is 93,000,000 / 238,900 or about 390.  So the sun is about 400 times larger than the moon, but it's also about 400 times farther away - so the sun and moon appear about the same size in the sky.\n\nThe moon's orbit around the earth isn't a circle, and the lunar distance varies from about 220,000 miles to about 252,000 miles.  When it is close to the earth, the moon appears slightly larger than the sun.  When it is in the further part of it's orbit, the moon appears slightly smaller than the sun.  If an eclipse occurs when the moon is furthest from earth, the moon's disk can't completely cover the sun.  The result is an "annular" eclipse.\n\nIncidentally, the moon gets slightly farther away from the earth every year.  Eventually, in the distant future, it will be too far away to produce a total eclipse of the sun.
83340
Solar system is 11 letters in size.\n\nTHE solar system or A solar system are different matters\n\nWe have these things in English called defintite articles. Words like "A" and "THE". Learn them. Use them.
606341
It depends on whether you are talking about a planet in our solar system or an extra solar planet. I'll describe both.\n\nFor a planet in our solar system, the apparent size can be directly measured optically. One way is to take a picture of the planet through the telescope and measure the size of the picture with a ruler. Calculations based on the focal length of the telescope will tell you how many degrees (or fractions of a degree, since it will be less than 1) wide the planet appears to be in the sky for a given measured size on the photograph. Then the distance to the planet must be measured, which is not so easy. Basically it comes from triangulation to nearby asteroids combined with kepler's laws. Knowing the distance and apparent size allows you to calculate the real size and volume. To get the density, you need to know the mass. If the planet has Moons, the orbital period of the moons gives you the planet's mass from orbital mechanics calculations. If the planet has no moon, like Mercury and Venus, then theoretically their mass can be gotten from the effect their gravity has on the orbits of other planets, asteroids and comets, but this is not so accurate since those other objects don't usually pass close enough to the planet we want to measure to show much of an effect on their orbits. Fortunately we have sent space craft to Mercury and Venus and measured their mass directly by the effect their gravity had on the space craft's path.\n\nFor a planet orbiting another star, it is not so easy, because such planets cannot even be seen. Their presence is deduced from tiny Doppler shifts of the star they orbit. A planet does not just orbit a star, the star and planet orbit each other around their common center of gravity. Since the star is much heavier than the planet, it doesn't move much, but it does move, and modern instruments can measure the tiny Doppler shift in the star's light to get the motion of the star. Stellar evolution models tell us how heavy the star is and orbital mechanics tell us how heavy the planet is. (We can calculate the mass of double stars using orbital mechanics and the Doppler shift of each star's light, but we have no direct knowledge of the mass of single stars.) If the planet also happens to orbit in a plane parallel to our line of site, it will cross directly in front of the star once each orbit, like Venus sometimes crosses the face of our sun as seen from Earth. When it does, it blocks a small percentage of the star's light and the star looks slightly dimmer. If the star dims by 1%, then the disk of the planet has 1% the area of the disk of the star. Again, from stellar evolution models, we can deduce the diameter of the star and so get the diameter of the planet. (We can measure the diameter of some large, nearby stars, directly with the largest telescopes and adaptive optics, but for most stars we have no direct knowledge of their diameter.)\n\nThere is much more detail, but enough is enough, don't you think?
637131
About  93 million miles depending on where we are in the orbit as the orbit is not circular. The sun is made of gas, and actually more of a plasma. The earth has a solid iron, nickel core with a molten iron nickel outer core and then then mantel then the crust with rock on it.
18543
The relative size of Earth, Jupiter, Sun = 1 : 10 : 100
924385
Usually Astronomical Units (AU's). \n\n1 AU is the mean distance of Earth from the sun.\n\n1AU = 92,955,800 miles\n\nMercury = .39 AU\nVenus = .72 AU\nEarth = 1 AU (of course)\nMars = 1.52 AU\nJupiter = 5.2 AU\nSaturn = 9.54 AU\nUranus = 19.18 AU\nNeptune = 30.06 AU
786773
Their distance from the Sun
490259
The mass of earth is found as follows.\n\nThe acceleration due to gravity at a place is g. \ng = G M/R^2, where, G is gravitational constant, which is determined experimentally with two known masses.\n\nR is the radius of earth which we know by surveying the circumference of earth.\n\n M = 9.8 x 6400,000 x 6400, 000x / 6.673x10^ (-11) = 6x10^24kg.\n\nThe mass of Sun is found as follows.  \n\nWe determine the distance of Sun observing their angular diameters measured from different heights from earth. \n\nWe observe its period of rotation about the earth.\n\nNow using the formula ‘M = 4pi^2 R^3/G T^2’, M is found\n\n39.48 x (1.496x10^11) ^ 3/6.673x10^ (-11){365.25x24x60x60}^2= 1.989x10^30 kg.\n\nSince we know the mass of Sun, we can use only the period of rotation to find the mass without knowing the distance.\n\nAbout the mass of stars, I don’t know whether there is some way to find their mass.
1043761
Observations have shown that in fact the sun is not shrinking.  In 5 billion years from now just as it uses up its remaining hydrogen it will still be 99.9% as big as it is now.\n In 1987, several astronomers from Paris Observatory made an announcement regarding the size of the Sun that astonished their colleagues (Kippenhahn, R., 1994, pg. 163). They claimed that solar eclipse data from 1666 to 1719 showed that the Sun was 2000 kilometers larger than it is today. This amounts to a 0.3 percent reduction; and the time period, which roughly corresponds to the Maunder Minimum, seemed to be more than coincidental. However, this data was found to contain an error regarding the 1715 solar eclipse path of totality. Consequently, the Sun was the same size in 1716 as it is today, and astronomers were reassured. \n\n\nReference\nR. Kippenhahn, Discovering the Secrets of the Sun, Wiley Press, 1994.
426077
The circumference of the earth at the equator is 24,901.55 miles (40,075.16 kilometers).
81303
The sun is 1,391,000 kilometers.  That translates to 1,391,000,000 meters.\n\nOne meter is 1.0936133 yards.  That means the sun's diameter is 1,521,216,100.3 yards.\n\nAn American football field is 120 yards (with endzones) for a total of 12,701,800 football fields.\n\nA Canadian football field is 150 yards (110 field and 2 20 yard endzones) for a total of 10,141,400 football fields\n\nA Soccer field is between 100 and 130 yards for a total of between 11,701,662 and 15,212,161 soccer fields.\n\nEDIT:\nThe Australian Rules Football field is between 135 and 185 meters for a total of between 7,518,918  and 10,303,703 Australian Rules Football fields.\n\nIf you would like width-wise calculations let me know.
1127024
sun....its a star btw but there are stars bigger than the sun
1054557
Biggest Thing "ON" Earth?\n\nSUN...  Yes... It is Sun
867403
The sun is made of hydrogen.
280098
It accounts for more than 99% of the mass in our solar system.\n\nIn terms of size, it is actually in the top 10% of the known stars. This means that it is actually larger than average, though in terms of a size-scale...largest-to-smallest existing stars...it is somewhere in the middle.\n\nThe sun contains every element that occurs naturally on Earth.