# Aliens blew up Pluto so we would stop debating whether or not to call it a planet, what happens to Earth? [closed]

It seems the Fraxians, an alien race from Alpha Centuri, have been secretly watching our television ever since we started broadcasting it (well technically I suppose 4.367 years after we started broadcasting it). They find Earthlings quite amusing, with the bizarre way we move using only two limbs, how funny we look with our bilateral symmetry, our absurd misunderstandings of science, and the adorable way we always depict other aliens as looking like us even though everyone knows most aliens species actually look more like a cross between a cat and a jelly fish. They even find it hilarious how we think it would be hard for them to decode our simple broadcasts.

However, this whole "is Pluto a planet" debate has just been so annoying for them to watch. If you ask their astronomers about Pluto they would tell you the debate is pointless since Pluto is clearly a wco'ad-lkod (sadly the word doesn't translate as well into the English language). Having gotten sick of the debate the Fraxians have decided to end it once and for all, by destroying Pluto so no one needs to decide what to call it.

So the Fraxians have re-purposed the Earthling-containment ray, originally intended to avoid human's contaminating the rest of the universe by destroy Earth the moment it looked like we may achieve interstellar travel. The Containment ray has been instead used to destroy Pluto. The entire not-planet has now been struck with enough power to cause Pluto to explode outwards, with piece thrown in every direction at high speed.

My question is what happens to earth now that Pluto no longer exists? Would the change in gravitational pull caused by the various pieces of Pluto rapidly changing position have any appreciable affect on the orbits of Earth and it's neighbors? What are the odds that a piece of Pluto makes it all the way to earth and gives us a new sympathy for the dinosaurs? Will we have to rename Mickey Mouses dog!?

This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See the tag description for more information.

## closed as too broad by Gary Walker, Nosajimiki, EDL, Trevor, DubukayJul 22 at 21:44

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• In this scenario, humans try to determine what happened to Pluto, but get bogged down in the debate of whether to call it the Rubble-Formerly-Known-as-the-Planet-Pluto or the Rubble-Formerly-Known-as-the-Dwarf-Planet-Pluto, and the fact that it was destroyed slips from the public awareness and is forgotten. – Frostfyre Jul 22 at 17:43
• "With piece[s] thrown in every direction at high speed": How many pieces? What's the distribution of piece sizes? What does "high speed" mean? What is the average speed? Where was Pluto when it exploded? – AlexP Jul 22 at 17:48
• It seems like the very first thing that would happen to the Earth is that we'd all -- for the first time in history -- unite together as one world and declare war on the Fraxians. – Admiral Jota Jul 23 at 20:47
• Well, after Pluto's demise it should be a matter of days before they also blow Uranus to stop the stupid jokes... That would have a more significant impact, if only by its mass. – SJuan76 Jul 23 at 20:49
• @AlexP, doesn't really matter. Shatter Pluto into ten million dinosaur-killer asteroids at perhelion with a uniform distribution of fragment directions, and you've only got a 1 in 200,000 chance of one of those pieces hitting Earth. – Mark Jul 23 at 20:51

PART ONE OF SIX: DETECTING THE DISAPPEARANCE OF PLUTO

It seems to me that if Pluto is exploded a lot of the matter in Pluto should turn into glowing gases. Thus the total luminosity of Pluto should increase drastically since it no longer merely reflects light but now also emits light.

First possibility:

So the next time an amateur astronomer looks at Pluto in a telescope or photographs Pluto, it will appear much brighter than normal. So eventually it will be known that amateur astronomers think that Pluto is much brighter than normal, and professional astronomers will decide to check it out. And they might discover that Pluto is now an expanding globe of glowing gases mixed with solid particles.

The most probable, or only, known way for a large body the size of Pluto to explode would be for it to collide with another body with sufficient force. And since the known large bodies in the Solar System have existed for about 4,600,000,000 years without being destroyed in collisions, the odds against such a collision happening to a specific astronomical body during all of human history so far would be - well, "astronomical".

Thus many humans will come to believe that the destruction of Pluto was a result of the evolution of humans, that super advanced powerful aliens deliberately destroyed Pluto as some sort of result of their discovery that humans exist.

Second Possibility:

Alternatively, nobody might look at Pluto until the cloud of glowing gases expands and cools so that it is no longer brighter than the background of outer space at visible wavelengths.

So the next time an amateur astronomer looks at Pluto in a telescope or photographs Pluto, they won't see or photograph anything where Pluto should be. So eventually it will be known that amateur astronomers think that Pluto has vanished, and professional astronomers will decide to check it out. And they might discover that Pluto's moons are now moving away from its location on tangents from their former orbits around it, and that the whole volume of space around Pluto's calculated position is filled with an expanding cloud of cooling gases mixed with solid particles that still emit infrared light at temperatures much higher than the cosmic background radiation.

The most probable, or only, known way for a large body the size of Pluto to explode would be for it to collide with another body with sufficient force. And since the known large bodies in the Solar System have existed for about 4,600,000,000 years without being destroyed in collisions, the odds against such a collision happening to a specific astronomical body during all of human history so far would be - well, "astronomical".

Thus many humans will come to believe that the destruction of Pluto was a result of the evolution of humans, that super advanced powerful aliens deliberately destroyed Pluto as some sort of result of their discovery that humans exist.

PART TWO: NO PLUTO HOLOCAUST?

What were the effects of the explosions of the First and Second Death Stars on Yavin IV and the moon of Endor?

TV Tropes has a trope called No Endor Holocaust where blowing up something large to save the day does not cause widespread casualties and destruction as it might be expected to do.

The trope is named after a theory that argues the destruction of the second Death Star in Return of the Jedi turned the Ewoks' homeworld, the Forest Moon of Endor, into a smoking wasteland. The Wookieepedia article explains that canonically, the Endor Holocaust did not happen, only existing as Imperial propaganda. Later material would Hand Wave it by explaining that the Death Star's destruction created a wormhole (long story; just know the Death Star was intended for faster-than-light capabilities) that sucked most of the debris (including The Glove of Darth Vader) into parts unknown, with any dangerous leftovers being caught in Rebel tractor beams...

PART THREE: AN EXPANDING SPHERE OF DEBRIS - A PLUTO CLOUD?

It is obviously possible that one way the aliens might destroy Pluto would be to simply explode it.

That would turn Pluto from a solid spheroidal body with a diameter of about 2,376.6 kilometers into an expanding spheroidal cloud of solid, liquid, gaseous, and plasma matter, containing subatomic particles, atoms, molecules, and perhaps pieces of matter of various sizes.

When the Pluto cloud has ten times the diameter of Pluto, or 23,766 kilometers, it will have one thousand times the volume Pluto had, and its density will be one thousandth of its former density.

When the Pluto cloud has one hundred times the diameter of Pluto, or 237,660 kilometers, it will have one million times the volume Pluto had, and its density will be one millionth of its former density.

When the Pluto cloud has one thousand times the diameter of Pluto, or 2,376,600 kilometers, it will have one billion times the volume Pluto had, and its density will be one billionth of its former density.

When the Pluto cloud has ten thousand times the diameter of Pluto, or 23,766,000 kilometers, it will have one trillion times the volume Pluto had, and its density will be one trillionth of its former density.

When the Pluto cloud has one hundred thousand times the diameter of Pluto, or 237,660,000 kilometers, it will have one quadrillion times the volume Pluto had, and its density will be one quadrillionth of its former density.

When the Pluto cloud has one million times the diameter of Pluto, or 2,376,600,000 kilometers, it will have 1,000,000,000,000,000,000 times the volume Pluto had, and its density will be 1/1,000,000,000,000,000,000 of its former density.

When the Pluto cloud has ten million times the diameter of Pluto, or 23,766,000,000 kilometers, it will have 1,000,000,000,000,000,000,000 times the volume Pluto had, and its density will be 1/1,000,000,000,000,000,000,000 of its former density.

The distance of Pluto from the Sun varies between 4,436,820,000 and 7,375,930,000 kilometers, so the Pluto cloud should reach Earth when the Pluto Cloud is between one million and ten millions times the diameter of Pluto, and thus when the Pluto Cloud has between 1/1,000,000,000,000,000,000 and 1/1,000,000,000,000,000,000,000 the density of Pluto.

The density of Pluto is 1.854±0.006 grams per cubic centimeter. The density of Earth's atmosphere at sea level is 0.0012 grams per cubic centimeter, or about 0.0006472 of the density of Pluto. So Earth's atmosphere at sea level is still millions and billions of times thicker than the Pluto cloud will be when it reaches Earth, which is good.

Triton, the large moon of Neptune, has a very, very thin atmosphere. It has a pressure of only 14 microbars, or 1/70000 that of Earth's surface pressure, or 0.0000142 of Earth's atmosphere at sea level. And yet it is dense enough to have visible effects, as rising clouds turn horizontal as they reach the wind levels. These winds blow at about 5 to 15 meters per second, or 18 to 54 kilometers per hour, or 11.18 to 33.55 miles per hour.

So ordinary speed winds can move airborne particles even in an atmosphere that is 1/70000 as dense as Earth's at ground level, and thus should be approximately equal to about 0.000000009 the density of the planet Pluto.

Of course the density of Triton's atmosphere is still over 1,000,000,000 times the density of the Pluto cloud when it expands to include Earth.

Meteroids burn up and glow in Earth's atmosphere at heights of about 75 to 100 kilometers (250,000 to 330,000 feet). And I think that the atmospheric density at those levels is equal to or below that of Triton's surface.

Obviously if Mars or the Moon exploded it would be far more likely to devastate Earth than if distant Pluto exploded.

PART FOUR: A SHELL INSTEAD OF A SPHERE?

But what if the expanding Pluto cloud is not a spheroid, but a shell since the contents of that shell have almost exactly the same speed outwards from the center of where Pluto was?

Suppose that sometime in 2020 Pluto's former position is 5,100,000,000 Kilometers from Earth when the shell first reaches Earth. Suppose that the shell has a thickness of 1,000,000,000 kilometers. The void inside the expanding shell should be an approximate sphere with a radius of about 4,100,000,000 kilometers, while the outer surface of the expanding shell should have a radius of 5,100,000,000 kilometers.

According to my rough calculations using figures of billions of kilometers and fractions of a billion kilometers for the radii, the shell would have a volume of 555.65 units if it was a sphere, the inner sphere should have a volume of 288.7 units, and the larger sphere minus the smaller sphere would have a volume of 266.95 units, the volume of the shell. So the shell would have 266.95/555.65, or 0.4804, of the volume of a sphere with a radius of 5,100,000,000 kilometers, and thus should have a density of matter that is about 2.0815 that of a spherical Pluto cloud with the same outer dimensions.

What if the Pluto cloud shell has a radius of 5,100,000,00 kilometers and a thickness of 1,000,000 kilometers? Then the sphere inside the shell will have a radius of 5,099,000,000 kilometers. So the outer sphere would have a volume of 555.65 units and the inner sphere will have a volume of 555.32. Thus the volume of the shell would be 0.33 units, which will be 0.33/555.65, or 0.0005938, of the volume of a sphere with a radius of 5,100,000,000 kilometers, and thus should have a density of matter that is about 1,682.8787 that of a spherical Pluto cloud with the same outer dimensions.

What if the Pluto cloud shell has a radius of 5,100,000,00 kilometers and a thickness of 1,000, kilometers? Then the sphere inside the shell will have a radius of 5,099,999,000 kilometers. So the outer sphere would have a volume of 555.6467401 units and the inner sphere will have a volume of 555.6464133. Thus the volume of the shell would be 0.0003268 units, which will be 0.0003268/555.6467401 or 0.000000588, of the volume of a sphere with a radius of 5,100,000,000 kilometers, and thus should have a density of matter that is about 1,700,680.272 times that of a spherical Pluto cloud with the same outer dimensions.

What if the Pluto cloud shell has a radius of 5,100,000,00 kilometers and a thickness of 1 kilometer? Then the sphere inside the shell will have a radius of 5,099,999,999 kilometers. So the outer sphere would have a volume of 555.6467401 units and the inner sphere will have a volume of 555.6467398. Thus the volume of the shell would be 0.0000003 units, which will be 0.0000003/555.6467401 or 0.0000000005399, of the volume of a sphere with a radius of 5,100,000,000 kilometers, and thus should have a density of matter that is about 2,000,000,000 times that of a spherical Pluto cloud with the same outer dimensions.

Clearly an exploding Pluto would produce a Pluto cloud that would devastate Pluto's moons. And if that Pluto cloud was an expanding shell instead of an expanding spheroid the density of matter could be great enough to devastate any comets, asteroids, etc. within millions of kilometers of Pluto's former position. It is uncertain whether that expanding shell could have enough density to seriously impact Earth when it reached Earth.

The orbital speed of Pluto averages about 4.7 kilometers per second - 16,920 kilometers per hour - and the orbital speed of Earth averages about 29.8 kilometers per second - 107,280 kilometers per hour. So when particles from Pluto reach Earth, the difference in their velocities will be significant, which will increase the impact of Earth being impacted by those particles.

Of course in order for Pluto to blow up and some of the fragments reach Earth the particles with have to have acquire a speed relative to their former position. That speed could be a tiny fraction of the difference between the orbital velocities of Earth and Pluto, or it could be many times the speed difference.

Obviously if Mars or the Moon exploded it would be far more likely to devastate Earth than if distant Pluto exploded.

PART FIVE: A SECOND SUN?

The amount of energy required to impart to every particle of Pluto's mass sufficient speed to escape from Pluto's gravity and not recombine would be immense. It would by a small fraction of the energy needed to explode Earth or Alderaan, but probably much more than the energy needed to explode either of the hollow Death Stars.

Imparting that much energy to the mass of Pluto should make that mass super hot. Which means that mass would radiate a lot of energy before it cooled off.

Pluto has a radius of 1188.3 kilometers, while the Sun has a radius of 696,342 kilometers, 585.998 times as large. When the expanding Pluto Cloud swells to have the same radius as the Sun, it should still be very hot. If the Pluto cloud has the same temperature as the Sun's surface when it has the same size as the Sun, it should emit the same amount and type of radiation as the Sun.

The distance of Pluto from the Sun and from Earth varies with time. Assuming that the Pluto cloud is about 39.48 Astronomical Units (AU) - an AU is the average distance between Earth and the Sun - from the Earth when it emits as much radiation as the Sun, the amount of radiation that Earth gets from the Pluto cloud will be the same as it gets from the Sun, divided by 39.48 squared (1,556.3016), or 0.0006425 as much.

Assume that the Pluto cloud emits 1,556.3016 times as much radiation as the Sun does when the Pluto cloud is 39.48 AU from Earth. Then Earth will receive exactly as much radiation from the Pluto cloud as Earth gets from the Sun.

If the Pluto cloud is exactly opposite to the Sun as seen from Earth, it will rise when the Sun sets and set when the Sun rises. Thus every part of Earth will have 24 hours a day of the equivalent of full sunlight. And the temperature of Earth will rise and rise and rise and mass die offs of plant and animal life will begin.

If the Pluto cloud appears right beside the Sun as seen from Earth, it will rise and set with the Sun, and Earth will heat up in the day and cool off at night as usual. But it will receive twice as much radiation as it usually gets, and thus will heat up more during the day than it cools off at night. So Earth's average temperature will rise and rise and rise each day and mass die offs of plant and animal life will begin.

And if the Pluto cloud is in an intermediate angle to the Sun as seen from Earth, the effects will be intermediate between the two extremes. No matter what the positions of the Sun and the Pluto cloud are when seen from Earth, if the Pluto cloud emits anything close to 1,556.3016 times the radiation of the Sun, Earth's goose will be cooked, along with all the geese.

And I have no idea whether the Pluto cloud will emit only a tiny fraction of the radiation emitted by the Sun or many times the radiation emitted by the Sun.

Obviously if Mars or the Moon exploded it would be far more likely to devastate Earth than if distant Pluto exploded.

PART SIX: WORMHOLE?

Of course the aliens might not simply explode Pluto to get rid of it. They might create an artificial wormhole and open one mouth of it right ahead of Pluto and its moons in their orbit. Pluto and its moons will enter the mouth of the wormhole and come out the other mouth of the wormhole in some other region of space and time.

Doing so would have very little effect on Earth, although the absence of Pluto would eventually be noticed. And possibly scientific instruments might notice some effects of the artificial wormhole while it is open.

So exactly how the aliens get rid of Pluto could determine whether nobody on Earth notices it for weeks or months at one extreme, or all life on Earth dies out within a few months on the other extreme.

• To be fair, many humans find anything happening to be proof of aliens existing and taking action on us. That doesn't mean reasonable humans with power will believe that. – Muuski Jul 22 at 23:15
• @Muuski Try calculating what are the odds against perhaps the 20th most massive object in the Solar System lasting for 4,600,000,000 years and then exploding due to an accidental collision less than 100 years after being discovered by humans. And depending on how the alien weapon works, the "crime scene" might show clear evidence that Pluto was not destroyed by an accidental collision with another large solar system body. – M. A. Golding Jul 23 at 16:02
• I was more talking about the types of people who walk into their backyard with a spray bottle of vinegar and shoot it up at passing airplanes because they believe their contrails contain mind control chemicals. – Muuski Jul 24 at 14:29

We wouldn't notice its gravity was gone, we might not even notice the bang. There's not enough of Pluto for it to have a marked gravitational effect on the Earth, according to the tidal force calculation:

$$F=\frac{2GM_1M_2d}{r^3}$$

Where:

• $$F$$ is the force exerted on Earth by Pluto
• $$G$$ is the Gravitational Constant
• $$M_1$$ is the mass of Earth
• $$M_2$$ is the mass of Pluto
• $$d$$ is the distance between them
• $$r$$ is the radius, in this case, of Pluto

Pluto exerts a mere 7.8x107N of tidal force on the Earth only 0.000000001% the average pull of the Moon. Furthermore as no-one currently has Pluto under routine observation it could be quite some time before we even realise it's gone. We'd notice if the aliens destroyed it by giving it a push into the inner system, it would be the biggest comet in our history but it would take a long time getting down here near the sun. Otherwise we might notice a slight increase in comet activity and then again we might put it down to something else, theory has it that Earth should be the victim of a large impact event in the geologically near future.

As a note if the aliens use the full 2.5x1032J that the device would need to blow Earth to bits on Pluto there's going to be an expanding ball of atoms where the planetoid was. The nebula-like effect this creates would be short-lived but we'd probably see it before the solar winds pulled it apart.

This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See the tag description for more information.

• This answer has been flagged as low quality, likely because it utilizes Wikipedia as its sole reference. I would suggest, at a minimum, relating the equations here to provide hard numbers to support your conclusion. – Frostfyre Jul 22 at 19:00
• @Frostfyre Does that look better? – Ash Jul 23 at 11:54
• It does. Are you familiar with Latex formatting? It would help the readability of the equation. I can apply it, if you want. – Frostfyre Jul 23 at 12:42
• @Frostfyre No I'm not, I've looked at Latex a couple of times but I cannot get it to work at all, if you can do it for me that would be much appreciated, maybe seeing how it should be done will help me next time too. – Ash Jul 23 at 13:10
• Done. See my edit. – Frostfyre Jul 23 at 15:25

Pluto’s gravity has no detectable effect on the rest of the solar system, and its absence will also have no detectable effect. The chances of a fragment striking the Earth depend on exactly how Pluto is destroyed, with the application of how much energy, breaking it into how many fragments, so you’ll need to provide those details.

Specifics are addressed in physics StackExchange question 'Pluto's gravitational pull on a person on the Earth's surface?' demonstrate the gravitational force exerted on the Earth by pluto (~10E-14 N) is on par with the gravitation attraction between two average adults.

This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See the tag description for more information.

• Whilst correct, it doesn't quite meet the "Hard Science" requirement, does it? – Starfish Prime Jul 22 at 18:15
• It also depends on when Pluto explodes - how close it is to Earth, what is in the way (is Jupiter between Earth and the Plutonic Asteroid Cloud? Is Neptune? Is the Sun?) – Chronocidal Jul 23 at 12:14