Would a Planetary Detonation Be Visible from Earth ...

[Gatekeeper]

... if it were, say, roughly an Earth-sized world between Mars and Jupiter? The entire planet would be destroyed (let's just say the world had an unstable core made worse by being so close to Jupiter). I ask because I'm reading a novel (fiction, obviously) where a planet blowing up out there was visible from Earth, turning the night sky into day for a while. So, realistic or not?

Furthermore, what about debris from the destroyed world? Would most of it settle into the present Asteroid Belt? If not, how much would spread throughout te Solar System? Would Mars, Earth or any other planet in the system get the crap kicked out of it by the rocky and metallic wreckage of the dead world?

And while I'm on the subject of out-of-this-world questions, just how destructive would gravity waves be? I think such waves a purely theoretical right now, but if they were proved to be real, could they, like water waves, be quite destructive? If so, what would their sources be? Stars? Black holes? Quasars? Upheavals w/i any of these things? Something else entirely?

Gatekeeper

[Whaleboy]

Well it wouldn't light up the sky; you'd need an apparent magnitude of roughly -20 or less for that (the Sun for comparison is about -26.

I just can't see the explosion of a planet causing that, unless it was, much closer to the Earth, say the same distance as the Moon. If it was that close, the consequences for Earth would be disastrous.

This all depends on the type of explosion. I'm assuming some kind of highly luminous explosion such as a nuclear blast. I don't think you'll have a planet exploding in such a manner, particularly if it passes to close to Jupiter. The planet would simply break apart. There'd be lots of fireworks of white-hot rock. It'd certainly be visible from Earth, and it would be brighter, but I think that would be mostly due to the increased surface area of the debris (as opposed to a spherical planet) reflecting more sunlight.

As for gravity waves... well bare in mind that the Earth-Sun system emits roughly 250-300 Watts in gravitational waves, which wouldn't even be enough to light my house. The effects from the disruption of a planet would be truly tiny.

[DRoseDARs]

Re: Would a Planetary Detonation Be Visible from Earth ...

Originally posted by Gatekeeper
... if it were, say, roughly an Earth-sized world between Mars and Jupiter? The entire planet would be destroyed (let's just say the world had an unstable core made worse by being so close to Jupiter). I ask because I'm reading a novel (fiction, obviously) where a planet blowing up out there was visible from Earth, turning the night sky into day for a while. So, realistic or not?

Unless the planet suddenly turns into a giant nuclear fusion bomb, it isn't bloody likely that the explosion would turn night-to-day here on Earth. If the planet is getting smashed into by a smaller body, that would be visible through larger telescopes. Think of the Shoemaker-Levy impact on Jupiter a few years back.

Furthermore, what about debris from the destroyed world? Would most of it settle into the present Asteroid Belt? If not, how much would spread throughout te Solar System? Would Mars, Earth or any other planet in the system get the crap kicked out of it by the rocky and metallic wreckage of the dead world?

Again, depends on how the planet goes. A high-speed impact would jettison material all over the place, though most of it would settle in orbit close to the original. Earth would be in grave danger from larger chunks. If the planet just vaporizes, then at most we'd get two light shows: One during, and one a few weeks/months/years later as small material reaches our atmosphere.

And while I'm on the subject of out-of-this-world questions, just how destructive would gravity waves be? I think such waves a purely theoretical right now, but if they were proved to be real, could they, like water waves, be quite destructive? If so, what would their sources be? Stars? Black holes? Quasars? Upheavals w/i any of these things? Something else entirely?

Gatekeeper

Haven't the foggiest clue.

[BeBMan]

Don't answer these question! Gatekeeper is planning something

[Gatekeeper]

Whaleboy, DRoseDARs:

Thanks for the insights! I'll also do a bit more digging around on Wikipedia and other online resources, but sometimes it's quicker to simply post the question(s) on a forum to let others have at it. Multiple minds are better than one!

Regarding gravity waves, I finished a book about a year ago where the Sun basically gave off multiple gravity waves, each one stronger than the last and, suffice to say, it didn't bode well for Earth when they hit. They basically rearranged the planet's surface and altered its orbit a bit, along with its tilt. The book was fiction, obviously ("Decipher" by Stel Pavlou).

Gatekeeper

[Gatekeeper]

Originally posted by BeBro
Don't answer these question! Gatekeeper is planning something

Well, unless what I'm doing is mimicked ala "Stranger Than Fiction" (a good movie, BTW, I recommend seeing it), we should all be safe. I think.

Gatekeeper

[DRoseDARs]

If our multi-dimensional (mathematically 11 dimensions) reality can be envisioned as a volume condensed into a sheet (space-time), then gravity is simply dents in that fabric. Those dents only form in the presence of bodies, so I'm not at all clear what is meant by "gravity waves." Yes, I've heard of them before in serious science discussion, but I really don't understand what they are supposed to be.

[Proteus_MST]

I don´t think that you could notice any difference in brightness here on earth, at least not if you watch the star where this destruction takes place with the naked eye.
The sun in every solar system already is very bright, which makes it difficult for every planetary explosion to outshine it.

Instruments measuring the brightness coming from this solar system could measur the difference however (and probably also spectral differences)

Gravitational shockwaves?
Not if you aren´t within the same system. Planets are really really small if compared to their star and have only a small gravitatipnal impact onto things outside of the solar system.

So there´s no need to plant a bomb in the Klingon moon Praxis, as it won´t be very spectacular if you blow it up

[Perfection]

Originally posted by Whaleboy
Well it wouldn't light up the sky; you'd need an apparent magnitude of roughly -20 or less for that (the Sun for comparison is about -26.

It sure as hell would! We're talking an explosion of at least 5x10^33 Joules here necceary to break the planet's binding energy (and it would probably be much much larger because you aren't gonna get perfect conversion) , the sun has a luminosity of 3.827×10^26 Watts.

We're talking weeks worth of solar energy here in a single event.

It would be pretty damn bright.

[DRoseDARs]

But based on Gate's description, this "planetary detonation" is little more than the planet breaking up, not literally exploding like a bomb.

[Kuciwalker]

Re: Would a Planetary Detonation Be Visible from Earth ...

Originally posted by Gatekeeper
... if it were, say, roughly an Earth-sized world between Mars and Jupiter?

Mars and Jupiter themselves are visible from Earth.

[Perfection]

Originally posted by DRoseDARs
But based on Gate's description, this "planetary detonation" is little more than the planet breaking up, not literally exploding like a bomb.

Blow up, break up, I'm not gonna argue the distinction. What I calculated is the energy needed to turn an earth massed body into a fine cloud of debris. And given it's a catastrophic event it probably will be much larger then the figures I gave.

5x10^33J is the minimum energy involved in breaking up/blowing up/ whatever the hell you want to call it.

[Proteus_MST]

There are enough scenarios where just a piece of the planet is blown away, think of Star Trek, the explosion of Praxis, where there also was only a piece of the moon missing.

Also much more likely than the whole planet getting turned into debris.

[DRoseDARs]

Originally posted by Perfection
Blow up, break up, I'm not gonna argue the distinction. What I calculated is the energy needed to turn an earth massed body into a fine cloud of debris. And given it's a catastrophic event it probably will be much larger then the figures I gave.

5x10^33 is the minimum energy involved in breaking up/blowing up/ whatever the hell you want to call it.

But there is a distinction, don't play semantics.

[Perfection]

Originally posted by DRoseDARs
But there is a distinction

Not as far as my calculations are concerned.

This is the minimum energy to go from planet to no planet.

It is clearly large enough to cause illumination of the night sky.