Starting in 2025, the Vera C. Rubin Observatory in Chile — funded by the National Science Foundation — will catalog the solar system from the ground...
"It took us 200 years to discover all the asteroids we know to date, about 1.2 million asteroids," Mario Jurić, the Rubin Observatory's solar system discovery team lead and the director of the University of Washington's DiRAC Institute, told Astronomy. "In the first three to six months of Rubin, we will double that."
That's one additional ground based observatory coming online in the Southern hemisphere. If we get our act together and build a lot more of these and other space based observatories we're going to see the true scope of the "shooting gallery". We really need to raise public awareness of this, as a planet based civilization we are taking our chances by ignoring the problem and assuming everything will be fine for a hundred or a thousand more years. All of our efforts at averting a climate catastrophe will be for naught if we get smoked by a rock big enough to fill the atmosphere with particulate matter and drop global temperatures for years afterward let alone anything bigger resulting in global firestorms and tsunamis.
And prevention wouldn’t require Bruce Willis to blow it up with nukes, like the DART mission all you’d need is to hit the space rock with a fast moving, small probe and alter its course by a millionth of a degree far enough out, could be the difference between hitting a city, landing in the ocean, or not hitting earth at all.
I'm quite sure it wouldn't work but was an interesting idea.
Of those 1.2 million orbits, how many are dangerous?
If it helps you sleep at night, over the billions of years earth has been in its current orbit, it’s already ‘eaten’ all the high risk asteroids.
What we’re dealing with now are very much the long-long-long tail hazards.
Which do exist.
But the earths crust was molten in it’s early life due in some large part due to persistent and high volume infalling asteroids, and that time is long gone.
Observing near earth objects (NEOs) requires shorter exposure times because their (apparent) motion is quite fast, and that has an impact on how faint the objects you can detect can be.
There are methods like synthetic tracking though, that can detect fainter objects (even those hidden in the noise, not visible by eye).
You probably wouldn't want to nuke it, because you risk buck shotting the earth with a cloud of asteroids. Having a vectored nuclear rocket also allows you to change your trajectory if your initial calculations are off.
>What we’re dealing with now are very much the long-long-long tail hazards.
How do you know this?
And it’s a simple bit of math.
Asteroid collisions with our planet (or any other planet) destroys the asteroid.
unless something is making ‘new events’ (creating new asteroids, which we know of little/no mechanism for), we’re currently left only with asteroids which have managed to avoid impacting us or another planet for the billions of years before now they’ve been floating around the solar system.
Over x billions of years, the 1 in 1000 events have all played out. The 1 in 1000000 events have all played out, etc, etc.
So we’re just left with the lowest odds events, aka the ones with the lowest probability/lowest risk of occurring. The long-long-long tail.
It doesn’t mean we won’t get whacked by a shoemaker/levy impact in the future, just that the odds of it occurring now are very very low compared to say several billion years ago when there were far more objects floating around that hadn’t terminated their orbits into something already.
Of course, we also have a lot more incentive now to prevent such an occurrence (as we have stuff we don’t want to have destroyed now) as compared to several billion years ago when we didn’t exist.
So worth investing into. But we’re not looking for common/predictable situations, we’re looking for very unusual occurrences and hoping for enough forewarning to make it easy to deal with the consequences.
If this was a matter of dealing with high probability events, we’d have a very different approach.