My Kerbin accidentally caught something...

[Mat2ch]

...is it bad, doctor?

And I wondered what that object was floating around Kerbin, when I was on my way to Gilly...

[Gaarst]

No, nothing bad, just a random asteroid that spawned in orbit around Kerbin.

Sometimes, asteroids spawn in closed orbit instead of just having a Kerbin intercept, that orbit is often very elliptical though.

[Whovian]

I was going to suggest it could have had a Mun assist into orbit, but that orbit doesn't look like it intersects Mun's SOI. Therefore, what Gaarst said.

[EliasDanger]

Maybe it threaded the needle and aerobraked in kerbin atmosphere. What's the perisapsis?

[Mat2ch]

Maybe it threaded the needle and aerobraked in kerbin atmosphere. What's the perisapsis?

But to brake in the atmosphere, it would have needed focus. So it's really just an asteroid which got somehow caught in an orbit.

But I promise you, I'll catch it and I'll mine it dry. A class D asteroid, so much fuel and for free!

[samstarman5]

As Mat2ch said. On rails, objects ignore atmosphere drag. I've left booster stages alone when their peri was well below 69k, and yet come back after a trip to Minmus to find them still speeding along like that's what they are supposed to do. At least with those I don't feel bad about terminating, since they were supposed to go boom in atmo.

That is a crazy angle, but it is possible Minmus might have contributed to it with its own wonky orbit. Not all asteroids have their orbit right on the ecliptic, and any one could just as easily make a pass over a pole of the Mun or Minmus on the way in, with them getting a bit of a slow down in the process. Or it just can be written up to the Kraken having its fun while your eyes are diverted to other things. Which, if that is true, that is definitely the Kraken being very nice. These days asteroids have grown in value a hundred fold so that would be like going on vacation and coming home to find a semi tanker parked on your front lawn filled with premium gasoline.

[LordFerret]

... that would be like going on vacation and coming home to find a semi tanker parked on your front lawn filled with premium gasoline.

Well, hell, why couldn't they have parked that thing there BEFORE I left for vacation? Would have saved me a few buck$.

[Rath]

No, nothing bad, just a random asteroid that spawned in orbit around Kerbin.

Sometimes, asteroids spawn in closed orbit instead of just having a Kerbin intercept, that orbit is often very elliptical though.

Acyually they all spawn as flybys but some get some help from the min to get captured.

[Gaarst]

Acyually they all spawn as flybys but some get some help from the min to get captured.

Not they don't.

As can be seen in the screenshot, that orbit doesn't intersect the Mun's in any way. And with patched conics, you have to have an encounter somewhere to get gravity assist. And even then your oribt will still intersect the body you used for your gravity assist.

Also, I doubt on-rails bodies are affected by gravity assists: with high enough time warp, you can get through a planet.

It's just that the asteroid spawn with a random position and speed relative to Kerbin. If that position is in Kerbin's SOI and if that speed is low enough, then the body spawns captured.

It could also be that they spawn in a solar orbit with just a Kerbin encounter, but for some reason on-rails orbit mess something up and the asteroid ends up being captured.

I personally support the first option more.

[Rath]

Oh, okay

[Red Iron Crown]

And with patched conics, you have to have an encounter somewhere to get gravity assist. And even then your oribt will still intersect the body you used for your gravity assist.

Why would it intersect the body giving the gravity assist?

[Varsi]

Why would it intersect the body giving the gravity assist?

That's just how orbital physics works. You can't get an orbit that won't encounter the same body again later with just the gravity assist. You'd have to encounter some other body or apply thrust to avoid that.

[Red Iron Crown]

Ah I see, I was taking it too literally. I thought the meaning was "will impact the body", not intersect its SoI.

[magnemoe]

Why would it intersect the body giving the gravity assist?

He probably think gravity turn, that is the gravity of Mun changes the trajectory and have the astroid enter orbit around kerbin.

For this to happen the astroid resulting orbit has to intercept Mun SOI at some time.

This asteroid has probably been captured because of floating point errors because it entered Kerbin SOI under high warp.

it has an Ap at the edge of kerbin SOI and low Pe so an very small change in speed will put it into orbit.

[Varsi]

I've often noticed map showing orbits like this but the object is ejected near the apoapsis. Same happens when burning to orbit Mun and you stop the burn immediately after map shows you are in orbit, you may still return to Kerbin SOI.

In this case it seems to stick to orbit tho?