Asteroid size meters or miles?

[nats]

One thing that I dont know - is the quote size of asteroids in meters or miles? Because if size E = 18 meters that is nothing where asteroids are concerned and yet getting hit by an 18 mile asteroid would be a civilisation killing event! I assume its meters because the rest of the game seems to be in decimal but if so the asteroid sizes are rather lame arent they?

When you consider that the Chicxub Crater was formed by a 10km asteroid and we have 1.2 million estimated asteroids of 100m or larger it would seem to make the Kerbal asteroids rather puny by comparison. I dont know why you would even bother tracking asteroids smaller than 10m to be honest.

[Redshift OTF]

It's meters. If you want to capture an asteroid for scientific purposes then you'll need one that is only meters in size.

[stringyquark]

Also remember that most of the game is scaled down by around a factor of 10 iirc.

[Kasuha]

A sphere 18 meters in diameter has volume of 3053 m3. Assuming it's a chondrite which is a common type of stone meoeorite, its density would be about 3 g/cm3 and total weight about 9160 tons.

KSP asteroids are made of substance three times less dense than meteorites in solar system. Their density corresponds to density of water or ice.

Edited April 2, 2014 by Kasuha

[Taki117]

A sphere 18 meters in diameter has volume of 3053 m3. Assuming it's a chondrite which is a common type of stone meoeorite, its density would be about 3 g/cm3 and total weight about 9160 tons.

KSP asteroids are made of substance three times less dense than meteorites in solar system.

So styrofoam? Explains why they bounce when they hit Kerbin (if they don't explode on impact.)

[cantab]

Metres!

As mentioned, remember the idea is these are small asteroids we can move around, just as NASA are planning on doing.

And a class E certainly won't look "rather puny" when your ship is clawed to it! (Well, unless your name is Whackjob.)

[UmbralRaptor]

Meters. Also, keep in mind that given the lower masses of Kerbin and Kerbol, impact speeds would usually be significantly lower (~3.5 - 24 km/s) than in real life (~11 - 70 km/s)

[Alpheratz]

A sphere 18 meters in diameter has volume of 3053 m3. Assuming it's a chondrite which is a common type of stone meoeorite, its density would be about 3 g/cm3 and total weight about 9160 tons.

KSP asteroids are made of substance three times less dense than meteorites in solar system. Their density corresponds to density of water or ice.

Yeah, I've noticed how asteroids are way too light for their sizes. Their terminal velocity is way too low when entering Kerbin's atmosphere.

[cantab]

The low terminal velocity is down to KSP's simple aerodynamic model, in which part drag is proportional to mass. The consequence is that almost all objects have the same terminal velocity. (There's a drag coefficient, but that's the same for almost everything except semi- or fully-deployed parachutes.)

[soo25]

Ksp uses the superior METRIC SYSTEM. It's metres

[Pds314]

One thing that I dont know - is the quote size of asteroids in meters or miles? Because if size E = 18 meters that is nothing where asteroids are concerned and yet getting hit by an 18 mile asteroid would be a civilisation killing event! I assume its meters because the rest of the game seems to be in decimal but if so the asteroid sizes are rather lame arent they?

When you consider that the Chicxub Crater was formed by a 10km asteroid and we have 1.2 million estimated asteroids of 100m or larger it would seem to make the Kerbal asteroids rather puny by comparison. I dont know why you would even bother tracking asteroids smaller than 10m to be honest.

The sizes are in meters.

Remember, even being much less dense than water (I found a D-type asteroid, at least 12 meters in radius, that only weighed in at 500 tonnes or so, while water would weigh >7300 tonnes for the same size and shape), Asteroids are big and heavy and hard to move as they are. An E-type can weigh in at several thousand tonnes, more than some of the heaviest heavy-lifters around.

If KSP had realistic density (perhaps 5000 kg/m^3) asteroids, a spherical asteroid that could fit comfortably inside a 2.5 meter tank would already weigh in at 41 tonnes.

A 12.5-meter in radius D-type would weigh in at 41000.

Attaching the new enormous S3-14400 tank to it and a NERVA to it would yield a relatively low 14 m/s of Delta-V.

A 125-meter in radius asteroid would of course weigh in at an enormous 41 megatonnes.

The aforementioned NERVA-powered ship would yield an unimpressive 1.4 cm/s of Delta-V.

Now that we have a sense of scale, what do you think trying to redirect asteroids multiple km in radius would be like? You'd need hundreds of thousands or millions of S3-14400s to make a worthwhile difference.

Also, if an asteroid were that immense, it would be visible in the sky when it was still half way to the moon.

Edited April 3, 2014 by Pds314

[chemieglennie]

What is the weight range of each class. I can't seem to find it anywhere.

I couldn't find the weight of one I targeted either, just the size.

I'm realising now that the ship I built is probably woefully inadequate.

[Sirrobert]

If you're confused between the metric, and you KNOW everything else is meters, where the crap to you get Miles from?

IF it was in the order of size of miles, it'd be kilometers. Ya know, because the rest of the game also useles the metric system

[TranquilTempest]

What is the weight range of each class. I can't seem to find it anywhere.

I couldn't find the weight of one I targeted either, just the size.

I'm realising now that the ship I built is probably woefully inadequate.

of each class? I'm not sure what the limits are, but I've seen A class asteroids between 4 and 10 tons, and I've seen E class asteroids between 2000 and 3000 tons.

[Pds314]

A sphere 18 meters in diameter has volume of 3053 m3. Assuming it's a chondrite which is a common type of stone meoeorite, its density would be about 3 g/cm3 and total weight about 9160 tons.

KSP asteroids are made of substance three times less dense than meteorites in solar system. Their density corresponds to density of water or ice.

Of course, a sphere 18 meters in radius would weigh 70000+ tonnes. KSP asteroids aren't made of ice. They are made of cork, snow, styrofoam or balsa wood.

[Kasuha]

Of course, a sphere 18 meters in radius would weigh 70000+ tonnes. KSP asteroids aren't made of ice. They are made of cork, snow, styrofoam or balsa wood.

Okay, looking at the asteroid scale someone posted on Reddit, it definitely looks like 18 meters in radius, at least.

Styrofoam it is, then. Funny thing they sink in water.

[Starstrider42]

Wait... asteroids sink in water, even though all other rocket parts float???

[cantab]

Clearly, the water doesn't HAVE density. It just repels some things, making them float, and attracts others, making them sink.

[Starstrider42]

Yes, but think about it from a coding perspective -- if some objects float in water and others sink (and I agree with you that KSP does not do proper buoyancy calculations in either case), then that must mean the game has separate code for floating objects and sinking objects. At the least, it's an annoying inconsistency in the game engine. At the most, it's an interesting pathway for modding.

[Pds314]

Okay, looking at the asteroid scale someone posted on Reddit, it definitely looks like 18 meters in radius, at least.

http://i.imgur.com/WFCya9u.png

Styrofoam it is, then. Funny thing they sink in water.

Wait... They sink in water? Hmm... Can someone say asteroid-powered submarines?

How It works:

Take an asteroid of sufficient size and put some parts on top to make it float. Fuel tanks, etc would be a good choice. Try to balance it so that it is just heavier than neutrally buoyant.

Put basic jet engines on it for propulsion somewhat below the center of mass.

Edited April 6, 2014 by Pds314