# size of the sun?? **URL:** \ **Category:** Factual Questions\ **Created:** [April 3, 2001, 6:30pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665 "2001-04-03T18:30:11Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![jjason](https://avatars.discourse-cdn.com/v4/letter/j/87869e/32.png) [@jjason](https://boards.straightdope.com/u/jjason)\ **Post date:** [April 3, 2001, 6:30pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/1 "2001-04-03T18:30:11Z")
how big is the sun and what is its size compared to the earth like the earth is a pool ball and the sun is a basketball thankx in advance carl sagan ---
**Author:** ![Podkayne](https://avatars.discourse-cdn.com/v4/letter/p/edb3f5/32.png) [@Podkayne](https://boards.straightdope.com/u/Podkayne)\ **Post date:** [April 3, 2001, 7:07pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/2 "2001-04-03T19:07:44Z")
The Sun is very big. The Sun’s radius is about 110 times the Earth’s radius. If the Earth were a pool ball (2 1/4 inches in diameter) the Sun would be about 20 1/2 feet across. **jjason** , kiddo, please take a deep breath and start using some punctuation. ---
**Author:** ![Bottle\_of\_Smoke](https://avatars.discourse-cdn.com/v4/letter/b/b9e5f3/32.png) [@Bottle\_of\_Smoke](https://boards.straightdope.com/u/Bottle_of_Smoke)\ **Post date:** [April 3, 2001, 8:52pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/3 "2001-04-03T20:52:05Z")
Funny this should come up. My son just did something like this as part of his solar system project for his school’s science fair (yeah, I know it’s not the most original idea, but he’s only in kindergarten). Anyway, we used the info in [this link](http://www.athena.ivv.nasa.gov/curric/space/sun/sunearth.html) to get the proportions. ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [April 3, 2001, 9:33pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/4 "2001-04-03T21:33:05Z")
See [http://www.noao.edu/education/peppercorn/pcmain.html](http://www.noao.edu/education/peppercorn/pcmain.html) [http://www.seds.org/nineplanets/nineplanets/intro.html](http://www.seds.org/nineplanets/nineplanets/intro.html) ---
**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\ **Post date:** [April 4, 2001, 1:16pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/5 "2001-04-04T13:16:07Z")
[sub]Whoa, jjason! Banned in less than 24 hours. Tch, tch, tch, tch, tch…[/sub] ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [April 4, 2001, 4:01pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/6 "2001-04-04T16:01:51Z")
One morning I noticed the sun was positioned just right to shine through the keyhole in my door and illuminate a circle of light through two rooms onto the opposite side of my house. I measured the diameter of the circle of light and the distance from the keyhole to the wall. Then knowing the distance to the sun was about 93 million miles I was able to calculate (using cross multiplication; ratios; similar sides of equal triangles; trig; whatever…I don’t remember exactly what I did) I calculated the diameter of the sun. I seem to rememer I was within a couple of percent of the accepted figure. ---
**Author:** ![LateComer](https://avatars.discourse-cdn.com/v4/letter/l/b5ac83/32.png) [@LateComer](https://boards.straightdope.com/u/LateComer)\ **Post date:** [April 4, 2001, 4:43pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/7 "2001-04-04T16:43:30Z")
You might be interested in [Boston’s museum of Science](http://www.mos.org/)’s exhibit called[A Community Solar System](http://www.mos.org/exhibits/current_exhibits/welcome_universe.html). It’s a proportionate model of the Solar System, with the Sun a 12 foot ball in the museum. The rest of the exhibits radiate out from the museum at proportionate distances from the model sun. Imagine my surprise when I was walking through the Cambridgeside Galleria mall and saw **Mars** sitting there by the stairs? ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [April 6, 2001, 1:58am UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/8 "2001-04-06T01:58:55Z")
The Sun is to a bowling ball as the Earth would be to a BB. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [April 6, 2001, 4:43am UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/9 "2001-04-06T04:43:19Z")
And if the Earth were the size of a billiard ball at 2.25 inches, and the Sun were 20.5 feet across, the star Betelgeuse would be 1.5 miles across in its quiescent state, then sometimes it swells up to 4.5 miles across! ---
**Author:** ![Badtz\_Maru](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@Badtz\_Maru](https://boards.straightdope.com/u/Badtz_Maru)\ **Post date:** [April 6, 2001, 5:24am UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/10 "2001-04-06T05:24:20Z")
> [@](#): > > \*Originally posted by Sigene \* > \*\*One morning I noticed the sun was positioned just right to shine through the keyhole in my door and illuminate a circle of light through two rooms onto the opposite side of my house. I measured the diameter of the circle of light and the distance from the keyhole to the wall. Then knowing the distance to the sun was about 93 million miles I was able to calculate (using cross multiplication; ratios; similar sides of equal triangles; trig; whatever…I don’t remember exactly what I did) I calculated the diameter of the sun. I seem to rememer I was within a couple of percent of the accepted figure. \*\* We did the same basic thing in science class in the 7th grade, except we used a magnifying glass outdoors. ---
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [April 6, 2001, 5:47am UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/11 "2001-04-06T05:47:07Z")
I heard somewhere something like, a 747 could (leaving fuel concerns aside) maybe circle the earth in about a day…the same plane would take a couple MONTHS to circle the sun. (And they’d need to crank up the AC pretty high too) ---
**Author:** ![Icerigger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/icerigger/32/432_2.png) [@Icerigger](https://boards.straightdope.com/u/Icerigger)\ **Post date:** [April 6, 2001, 9:39am UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/12 "2001-04-06T09:39:04Z")
The sun is about 860,000 miles in diameter compared with the Earth at 7,926 miles, quite a bit larger. The mass of Sol is about 330,000 times ours. ---
**Author:** ![Jman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jman/32/4416_2.png) [@Jman](https://boards.straightdope.com/u/Jman)\ **Post date:** [April 6, 2001, 2:56pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/13 "2001-04-06T14:56:55Z")
> [@](#): > > \*Originally posted by LateComer \* > \*\*You might be interested in [Boston’s museum of Science](http://www.mos.org/)’s exhibit called[A Community Solar System](http://www.mos.org/exhibits/current_exhibits/welcome_universe.html). > > It’s a proportionate model of the Solar System, with the Sun a 12 foot ball in the museum. The rest of the exhibits radiate out from the museum at proportionate distances from the model sun. > > Imagine my surprise when I was walking through the Cambridgeside Galleria mall and saw **Mars** sitting there by the stairs? \*\* There’s a solar system model in Ithaca, NY (where I live) in honor of late Cornell professor Carl Sagan. It has monuments for each of the planets and the sun, in scale distances. Mercury is about 35 feet from the sun statue, Jupiter is about 2 blocks away. Pluto is around a kilometer or so away. They’re completing the “planet walk” as they call it by placing a monument for Alpha Centauri - In **Hawaii.** In each monument it shows the relative size for the planet in question. There’s a huge circle that represents the sun’s size, with a dot of the right proportion representing the planet inside the big circle. There’s also lots of info on each monument about the particular celestial body. If you want, you can see a [Picture of the Sun monument](http://www.sciencenter.org/SaganPW/sagansun.jpg) The first monument in the background is Mercury. The Planet Walk homepage can be found [here.](http://www.sciencenter.org/SaganPW/) Jman ---
**Author:** ![tshirts](https://avatars.discourse-cdn.com/v4/letter/t/839c29/32.png) [@tshirts](https://boards.straightdope.com/u/tshirts)\ **Post date:** [April 6, 2001, 8:44pm UTC](https://boards.straightdope.com/t/size-of-the-sun/60665/14 "2001-04-06T20:44:27Z")
If it’s a “pool ball/ basketball” sort of analogy you want, my favorite is: You can blot out the setting sun by holding a dime at arm’s length. (Attempt at sundown only please, don’t burn your eyes at noon!) Makes the mysterious sun seem more in scale with your life, doesn’t it 😉