Seems highly unlikely these crazy 'from outside the solar system' ideas are likely.
This meme spreads well, but that to me means there is far more chance it is not true. The fact no one questions it also seems suspicious.
This meme spreads well, but that to me means there is far more chance it is not true. The fact no one questions it also seems suspicious.
This left about 24 km/s faster than anything can go and remain inside of the Solar System. Do you have any idea how much energy it takes to get something going that fast?
A baseball going that fast has about 42 megajoules of kinetic energy. A semi on the interstate has about half a megajoule of kinetic energy. This thing was at least 100 meters long and all of it was going that fast.
For the record we do not have the technology to fire a rocket that fast. We only managed to get rockets to leave the Solar System by loading them up with gravity assists from planets. And even so they didn't get to that speed. If two asteroids have a head on collision, the pieces won't move that fast. (And it would have to be a heck of a collision to make a piece that big.)
If this came from inside of the Solar System, WTF accelerated it, how did it do so without breaking the object into smithereens, and why didn't we see evidence of the event that caused it?
By contrast this was going just about the average speed of interstellar objects in our neighborhood. (The Sun happens to be just passing through the ecliptic, and spends most of its time well above or below the Milky Way. Therefore to us, everything in our neighborhood is moving fast.) Any junk hanging around would have a trajectory that looks like this one. Now obviously space is pretty empty. Which is why it is so impressive that we actually spotted something from space.
Yes. It is highly unlikely that anything we see in the Solar System didn't come from here. But it is effectively impossible for anything starting in the outer reaches of the Solar System to get to this speed. And extremely likely that an interstellar object would go about this fast. Therefore it probably is an interstellar object.
1. It may have stolen some energy from another object (an accidental gravity assist), but we know that it didn't come close enough to anything big on its way though.
2. It came from outside the solar system and so entered with some velocity, and therefore will leave with roughly the same velocity it came in with.
We have well known mechanisms to eject objects from star systems so it isn't crazy to have things passing through. No-one questions it because high school level physics is enough to show why it is the only reasonable explanation.
We know it's 'possible' for a tennis ball to go through a wall. But it's not actually within the realms of the possible.
So I guess I still question the 'crazy' part. What are the mathematics here.
If a planet breaks into 5000000000000000 (Earth / Oumuamua) pieces how many hit another solar system? I'd expect zero, but have no idea.
I think it's more likely 1. We missed the fact it went close to another body or it's in a complicated gravity assist eons in the making.
But you're still focusing on the wrong thing. The idea of "a complicated gravity assist" getting something going this fast in the Solar System is laughable. The only thing in the Solar System heavy enough to do a gravity assist on the necessary scale is the Sun itself, and it started nowhere near the Sun.
For it to be real I'd expect billions of things passing through yearly, maybe daily. For something as large as Oumuamua I'd intuitively expect millions or billions of small rocks coming through.
"We find that such objects collide with the Sun once every 30 years, while about 2 pass within the orbit of Mercury each year."
But I worry about anything like this talking in human years, like "30 years". I'd expect every million years or millions a year when talking about the universe.
I understand as our technology grows, first we find yearly events and then improve. But the theoretical must make sense to me in non human timelines.
The Solar System is big. Almost all of them will pass through and miss everything. We literally have no way to notice them.
Incidentally we have spotted a second interstellar object. https://en.wikipedia.org/wiki/2I/Borisov is more what we were expecting them to look like.
Also, most (interior) walls are far weaker than you might expect.