Hello. I’m Rusty Schweickart and I’m writing this blog in order to introduce you to the basics of what we refer to as Planetary Defence or simply PD. Planetary Defence is the name given to the process of protecting the planet from asteroid impacts. More to the point, protecting life on planet Earth from the destructive effects of future asteroid impacts.
In particular, I’m writing this blog as a primer on what the public should know about asteroids, asteroid impacts, and the actions being taken to either mitigate the effects of impacts or actually prevent their occurrence entirely. Most important is what you should know to protect yourself if you should have the incredibly bad luck to be located near where one impacts. Happily the actions you should take are pretty simple, as you’ll see.
I’ll be dealing with the information in this blog with three priorities in mind; 1) what you need to know, 2) what you should know, and 3) what you might like to know. I may end up highlighting these so that you know which category of importance I believe is relevant to what’s being said.
And as we go ahead it will be very helpful to have feedback from you so that I don’t make the terrible mistake of assuming that I said something so clearly that of course you got it! I’ll attempt to answer all questions and some I’ll also replicate within the blog to share with everyone.
From time to time I may also add a sidebar on some particular item in order to explain something in a bit more detail without disrupting the general flow of the mainline thought. My goal in all of this is to present useful information about a pretty technical subject in a plain and understandable way. This is tricky because in making some issues easily understandable the precise details of a highly complex matter will have to be approximated. This will cause consternation for some, but making the issues understandable for non-technical people is my objective and in general, a first order approximation is good enough.
Another important element of this blog will be inserting specific references to many, if not most, of the subjects I’ll be introducing. These references will most often be links to expert or informative sources on the internet that you can click on to get more detailed information. From time to time I may also ask a specific expert to also add his/her own comment or expansion on something I’ve said. Or perhaps to respond to one of your questions.
Finally, before we get started, I’ll just mention here the scope of what we’ll be dealing with. Obviously asteroids themselves, per se. But mainly what’s of importance is their orbits, their sizes, their speed and how they come to crash into the Earth in the first place. How we discover near-Earth asteroids (NEAs) or near-Earth objects (NEOs), the asteroids that are of interest here, is important. How many are there of what sizes and how frequently do they impact Earth is also important. More fun perhaps will be when we get into predicting impacts and actually preventing impacts by deflecting incoming asteroids. And then there’s the somewhat puzzling issue to many people of why the PD challenge has a critical international dimension. In fact the UN is involved, and as we will see, this is important and essential, even if not quite obvious.
We’ll get there. But first we’ll start with some what-you-need-to-know-information. To introduce this I’ll ask you to imagine yourself being a homeowner in Chelyabinsk, Russia in early February, 2013. Only in this instance, instead of being completely surprised by an asteroid impact, as the citizens of Chelyabinsk were on that morning, we’re going to assume that the planetary defense system we’re in the process of forming was already, albeit barely, in place.
So off we go…