Episode 44 - asteroid impacts, chemical evolution and quasi-stars

So my first paper, two papers, I guess, is on asteroids impacting the solar system planets and the moon.

paper one and paper two.

So paper one is on the collision rates from end body simulation.

So basically the prediction part and then paper two is comparing that to the measured impact rates of various bodies throughout the solar system and sort of talking about the problems with both the predictions and then also how we define the number of things that have hit planets.

So that's kind of the two papers bringing together then, do we now better understand the rate of flux, I guess, of impactors in the solar system onto, you know, planets and the moon.

So this paper is, it's got two authors, it's Qi Feng Cheng and Daniel Skolnick, and they're both at Duke University in the US.

And the basic, very serious question here.

So it was very rare that we have like things that we really are like very relevant to our lives in astronomy.

Like the science is cool.

The knowledge is cool, but it's kind of a low stakes science game or no one dies.

However, asteroids hitting planets, that can be a bit more of one thing we definitely care about.

We want to understand well so that we can avoid that and deal with any incoming threats.

So trying to figure out how and when and what kind of things might impact the Earth now and in the future is a really ongoing challenge.

an active area of research and we have new telescopes coming online that should be able to give us a better handle on the near earth objects, for example, like with LSST, which has already found loads of new asteroids, I think as part of its opening survey.

But what we want to know at the end of the day is how many asteroids and of what size do we expect to hit the earth? And this, if we know this, we can also then better help like plan things like planetary defense schemes.

So intercepting asteroids, deflecting asteroids and so on.

And the sooner you know about them, the better, because then they're easier to move out of the way.

What we want to really infer is how many are sort of the larger ones are going to hit.

So for small things that are going to burn up in the atmosphere without much song and dance, we're not so worried, although it's cool to know that.

But once you get to objects that are sort of of the order of 10 meters, then you start to get things like your fireballs.

And as you go, you know, you start to get very big, potentially dramatic events as you move up and up in size scale.

So how many of these 10 meter, 10 meter plus type objects will impact the earth? We can sort of already understand how many have impacted the earth using sort of viable records and bolide records, which is where you can kind of track through the rocks, what may have impacted the earth and when.

And you get then an idea of the rate of these kind of impacts over time.

Now, we then can also sort of make predictions for how often we expect things to happen.

What we find is the observations and the predictions based on the near-Earth object population don't really agree very well at all.