The trouble I have with statements like this is that “as we know it” is doing so much of the heavy lifting. We don’t have any experience with extraterrestrial life so it’s difficult to imagine how different or similar it may be to our own. We have a sample size of 1 with a completely unknown population. The best we can do right now look at line spectra and make inferences from organic chemistry. But that tells us very little about the potential forms life may take.
I never got that. Surely, it's nearly as likely to divert an asteroid that would miss us to a course that would hit us as it is to do the opposite, right? The number that are actually trapped/impacted is a tiny percentage, and then the percentage of those that would have hit us must be a small percentage of that, is it really enough to be statistically significant?
Jupiter has a huge influence in the Solarsystem, the big gravitation of Jupiter and also the Sun can deflect most of the asteroids and Comets from the Earth orbit, but in certain circumstances can do the opposite and launch objects into Earth's orbit, depending on what angle they enter the system..
A good example is Apophis (∅~370 m), which is coming to visit us in 2029, although at quite a distance, but it will return in Abril 2036 and in this case, if it passes through a certain point there is a possibility that it will impact the Earth..
There are several plans to avoid it, but it depends of several factors. We can avoid an impact if we know the exact position several Years before the supposed impact, if not, there is nothing we can do.
Explain to me, how is Jupiter deflecting a significant number of asteroids if it can only be in one place at any one time and its orbit is nearly 12 years long? Wouldn't asteroids have a huge window to get past it while it's on the other side of the sun?
Same thing for Earth, it can only be at one place at anytime, creating a huge window for any asteroid to missed earth. And when it missed, it must loop around and orbit the sun, multiple times, increasing the chance of it got caught in Jupiter's gravitational well, which is a pretty massive distance.
Orbital mechanic is crazy and make no sense for a peasant like me. You would think hitting the sun is the easiest thing but It's actually really hard to launch something into the sun. And would require an enormous energy to do so.
Ever wonder why don't we just launch our nuclear waste into the sun? I thought so too and do some Google search about it. It was an interesting read.
I'm pretty sure I remember reading that Jupiter's "protector" status might also be overblown, as it actually sends asteroids into the inner solar system as well.
I dont know for sure, but its likely to do with the fact that the asteroids orbit the sun too. Even if the asteroid is coming in on the other side of the sun from jupiter, it has to orbit the sun in order get there in the first, meaning there's a good chance it gets caught by jupiter before it can get close