# Requirements for moving a planet? **URL:** \ **Category:** Factual Questions\ **Created:** [August 6, 2013, 7:14pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515 "2013-08-06T19:14:00Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [August 6, 2013, 8:55pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/21 "2013-08-06T20:55:28Z")
> [@leahcim](#): > > The most practical method I’ve heard of to adjust a planet’s orbit would be to set yourself up with a mass driver and start hurling rocks towards the offending planet so that said rocks make a slingshot orbit around the planet. Eventually the rocks will transfer enough momentum to the planet to make a difference. This. Done correctly, you could make a continuous loop of rocks around your target planet and one, or preferably two other objects, such as the Sun and Jupiter. The momentum transfer would be small, but it could be continuously repeated. See this essay by the late Paul Birch > **[MoveAPlanet.pdf](https://www.orionsarm.com/fm_store/MoveAPlanet.pdf)** ---
**Author:** ![Frazzled](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/frazzled/32/3368_2.png) [@Frazzled](https://boards.straightdope.com/u/Frazzled)\ **Post date:** [August 6, 2013, 9:42pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/22 "2013-08-06T21:42:33Z")
It’s so obvious even a kid could do it - you simply lower the local gravitational constant around the planet and it will move itself. Note, the kids who can do this are in the Q Continuum. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [August 6, 2013, 9:48pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/23 "2013-08-06T21:48:58Z")
> [@Ethilrist](#): > > Larry Niven used this method in one of his novels set WAY in the future… you place a giant fusion ramscoop engine in the upper atmosphere of one of the gas giants, tough enough to last pretty much forever and with a level of buoyancy that it’ll float at a certain altitude. When you need thrust, turn on the fusion drive (as mentioned above, turn it off when the planet rotates far enough that you’re pushing it off-course; this also allows the huge engine (the size of a small moon or Death Star) to bob back up to the point where it floats). Rinse, repeat as needed until you’ve moved the gas giant into an orbit that has it pass by Venus (to drag it away from the sun) or Mars (to bring it in closer), then park it somewhere in a more stable orbit until you need it again. [A World Out of Time](http://en.wikipedia.org/wiki/A_World_Out_of_Time); the gas giant used was Uranus. As I recall the fusion engine was a “double ended candle” model, one drive flare facing to space and pushing the engine against the planet, the other holding the engine up against it’s own thrust. It floated when not in operation. ---
**Author:** ![Aquadementia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aquadementia/32/555_2.png) [@Aquadementia](https://boards.straightdope.com/u/Aquadementia)\ **Post date:** [August 6, 2013, 10:19pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/24 "2013-08-06T22:19:36Z")
It’s relatively simple. You encase a star in a shell and when you open a vent on one side the star moves in the opposite direction. It’s like letting the air out of a balloon. The planet will naturally move along with the star. To earn a Class 3 Planet Juggler certification one must either make all the planets in a system switch places or reverse their orbits without losing so much as a moon. It’s a common enough sport among the elite of the galactic core, but I warn you the insurance premiums are out of this world. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 6, 2013, 11:29pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/25 "2013-08-06T23:29:30Z")
You’re all thinking too high tech. We could do it today. Just get all the people on one side of the earth to jump up and down at the same time. Then twelve hours later, get all the people on the other side of the earth to do so. Alternate every twelve hours. It would only take a second out of everybody’s day. Sure, it’ll be gradual, but so are all the other methods. And this one is far cheaper, too. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [August 6, 2013, 11:31pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/26 "2013-08-06T23:31:23Z")
> [@Aquadementia](#): > > It’s relatively simple. You encase a star in a shell and when you open a vent on one side the star moves in the opposite direction. It’s like letting the air out of a balloon. The planet will naturally move along with the star. [Stellar engines](http://en.wikipedia.org/wiki/Stellar_engine) have been theorized, although they’d need to be more elaborate than that. For one thing, building that shell would be the hard way of doing it, even it it’s possible. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [August 6, 2013, 11:37pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/27 "2013-08-06T23:37:19Z")
[Already addressed in this little-known column named “The Straight Dope.”](http://www.straightdope.com/columns/read/2869/could-we-move-mars-or-venus-into-earths-orbit-and-live-there) ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [August 6, 2013, 11:44pm UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/28 "2013-08-06T23:44:29Z")
> [@Asympotically\_fat](#): > > A long enough lever and a fulcrum on which to place it. Archimedes had this one solved 2300 years ago. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [August 7, 2013, 1:06am UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/29 "2013-08-07T01:06:27Z")
We could throw rocks. ---
**Author:** ![pravnik](https://avatars.discourse-cdn.com/v4/letter/p/8edcca/32.png) [@pravnik](https://boards.straightdope.com/u/pravnik)\ **Post date:** [August 7, 2013, 2:13am UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/30 "2013-08-07T02:13:05Z")
> [@Keeve](#): > > Simplest approach would be to just transport the star elsewhere. For very large values of “simple.” 😃 ---
**Author:** ![Don\_t\_Panic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/don_t_panic/32/398_2.png) [@Don\_t\_Panic](https://boards.straightdope.com/u/Don_t_Panic)\ **Post date:** [August 7, 2013, 2:54am UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/31 "2013-08-07T02:54:56Z")
> [@Exapno\_Mapcase](#): > > You’re all thinking too high tech. We could do it today. > > Just get all the people on one side of the earth to jump up and down at the same time. Then twelve hours later, get all the people on the other side of the earth to do so. Alternate every twelve hours. It would only take a second out of everybody’s day. > > Sure, it’ll be gradual, but so are all the other methods. And this one is far cheaper, too. [Just don’t try this in Rhode Island.](http://what-if.xkcd.com/8/) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 7, 2013, 3:02am UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/32 "2013-08-07T03:02:42Z")
> [@Martian Bigfoot](#): > > [Just don’t try this in Rhode Island.](http://what-if.xkcd.com/8/) I defer to the level of expertise disclosed in your username. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [August 7, 2013, 6:25am UTC](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515/33 "2013-08-07T06:25:12Z")
> [@Der\_Trihs](#): > > [A World Out of Time](http://en.wikipedia.org/wiki/A_World_Out_of_Time); the gas giant used was Uranus. As I recall the fusion engine was a “double ended candle” model, one drive flare facing to space and pushing the engine against the planet, the other holding the engine up against it’s own thrust. It floated when not in operation. In other words, if you’re seriously thinking about moving the entire Earth, you’re blowing gas out of Uranus. [Previous page](https://boards.straightdope.com/t/requirements-for-moving-a-planet/665515.md?page=1)