# Why does the earth have an atmosphere **URL:** \ **Category:** Factual Questions\ **Created:** [April 11, 2012, 12:38am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419 "2012-04-11T00:38:58Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 12:38am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/1 "2012-04-11T00:38:58Z")
The moons tidal pull on the earth, as does other gravitational forces effect the earths iron core the same way as it effects the oceans. This friction causes heat that keeps our core molten and rotating. This dynamo effect creates a magnetic field around the earth that protects us from radiation etc. The earths gravity also plays its part. [EMAIL=“[GTIMETO@HOTMAIL.COM](mailto:GTIMETO@HOTMAIL.COM)”]GTIMETO@HOTMAIL.COM SUPPORT AND REBUTTALS APPRECIATED!!!😉 ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [April 11, 2012, 1:00am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/2 "2012-04-11T01:00:34Z")
What column is this in reference to? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [April 11, 2012, 2:16am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/3 "2012-04-11T02:16:03Z")
Is the OP a question, a comment or a rant? ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 2:21am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/4 "2012-04-11T02:21:57Z")
A twist on “does the moon rotate”. The earth effects the shape and rotation of the moon. It figures the opposite is true, lets include the sun and other gravitational forces. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [April 11, 2012, 2:25am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/5 "2012-04-11T02:25:57Z")
Try telling us which column or report you are talking about so we have a common starting point. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [April 11, 2012, 2:31am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/6 "2012-04-11T02:31:38Z")
> [@gtimeto](#): > > A twist on “does the moon rotate”. The earth effects the shape and rotation of the moon. It figures the opposite is true, lets include the sun and other gravitational forces. Are you referring to [this column?](http://www.straightdope.com/columns/read/429/why-does-the-same-side-of-the-moon-always-face-the-earth) ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 5:21am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/7 "2012-04-11T05:21:24Z")
ok ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 5:42am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/8 "2012-04-11T05:42:37Z")
If one has ideas or theories he wants to share and wants public input. Where should he post them? ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 5:45am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/9 "2012-04-11T05:45:27Z")
> [@Czarcasm](#): > > Are you referring to [this column?](http://www.straightdope.com/columns/read/429/why-does-the-same-side-of-the-moon-always-face-the-earth) Yes this column. ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 11, 2012, 5:50am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/10 "2012-04-11T05:50:46Z")
> [@gtimeto](#): > > If one has ideas or theories he wants to share and wants public input. Where should he post them? The ‘General Questions’ forum is the place to post if you’re looking for factual answers. And let me be the first to say, “Welcome to the Straight Dope”! 😃 ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 11, 2012, 5:57am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/11 "2012-04-11T05:57:40Z")
Reported for forum change. ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 6:00am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/12 "2012-04-11T06:00:18Z")
> [@JBDivmstr](#): > > The ‘General Questions’ forum is the place to post if you’re looking for factual answers. > > And let me be the first to say, “Welcome to the Straight Dope”! 😃 I will give that a try.🙂 Why does it say bad example under your user name? ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 11, 2012, 6:06am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/13 "2012-04-11T06:06:46Z")
> [@gtimeto](#): > > … Why does it say bad example under your user name? If you knew me well, you wouldn’t have to ask. 😉 ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 6:07am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/14 "2012-04-11T06:07:20Z")
> [@JBDivmstr](#): > > Reported for forum change. what does reported for forum change mean?😃 ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 11, 2012, 6:08am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/15 "2012-04-11T06:08:58Z")
> [@gtimeto](#): > > what does reported for forum change mean?😃 It just means that I pointed the thread out to the Mods so that they can move it to the appropriate forum. 🙂 ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 6:09am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/16 "2012-04-11T06:09:19Z")
> [@gtimeto](#): > > I will give that a try.🙂 Why does it say bad example under your user name? I will take that for what its worth!!!😉 ---
**Author:** ![gtimeto](https://avatars.discourse-cdn.com/v4/letter/g/b9e5f3/32.png) [@gtimeto](https://boards.straightdope.com/u/gtimeto)\ **Post date:** [April 11, 2012, 6:13am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/17 "2012-04-11T06:13:13Z")
> [@JBDivmstr](#): > > It just means that I pointed the thread out to the Mods so that they can move it to the appropriate forum. 🙂 Till Later, Bad Example.:dubious: ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 11, 2012, 6:22am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/18 "2012-04-11T06:22:18Z")
> [@gtimeto](#): > > Till Later, Bad Example.:dubious: The same to you. Have a great day and a better tomorrow. 🆒 ---
**Author:** ![C\_K\_Dexter\_Haven](https://avatars.discourse-cdn.com/v4/letter/c/b2d939/32.png) [@C\_K\_Dexter\_Haven](https://boards.straightdope.com/u/C_K_Dexter_Haven)\ **Post date:** [April 11, 2012, 11:05am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/19 "2012-04-11T11:05:53Z")
**gtimeto** : welcome to the Straight Dope Message Boards. We have different forums for different types of questions. You had posted in a forum that is devoted to questions about Cecil’s columns, and that’s why some posters were trying to be helpful by locating the column, so we would have some common starting point. Based on your comments since, I have moved this to a forum devoted to straightforward question-and-answer. Paying members have the ability to write their own titles under their names. Non-paying posters appear as “Guest” (lilke under your name); paying posters like **JBDivmstr** can select their own title, and he’s selected “Bad example.” Moderators and Administrators like myself have two lines. That help? ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [April 11, 2012, 11:41am UTC](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419/20 "2012-04-11T11:41:25Z")
I’m not convinced that the Earth’s magnetic field explains why we have an atmosphere - many planets have an atmosphere of some sort, including IIRC all of the planets in the solar system (bar Mercury, which is too small and hot and close to the Sun to retain one) and a number of the larger moons. Mostly we have an atmosphere because of the initial chemical makeup of the Earth combined with gravity keeping it “stuck” to the planet. If you want to discuss why we have this particular atmosphere, that’s a different question. [Next page](https://boards.straightdope.com/t/why-does-the-earth-have-an-atmosphere/618419.md?page=2)