Summary: Asteroid and comet impacts have changed the course of life on Earth, and will again until we prevent them. Which will happen, eventually, when we go deeper into space. On Asteroid Day, June 30, let’s learn about this risk, what steps we can take now to better prepare. Perhaps it is humanity’s role, our purpose, to defend the planet. See the previous posts in this series; the links are at the end.
“The dinosaurs became extinct because they didn’t have a space program. And if we become extinct because we don’t have a space program, it’ll serve us right!”
— Science fiction author Larry Niven, as quoted by Arthur C. Clarke.
Here’s a graphic showing how to defend Earth from comets & asteroids.
These are the tools that we’d use for various combinations of time & intruder size.
This is what we’d try — as a desperate gamble or well-prepared response.
Better preparation & more warning time means better odds of success.
NRC’s “Defending Planet Earth: Near-Earth Object Surveys & Hazard Mitigation Strategies“.
Graphic by Tim Warchocki. Copyright © NAS.
How likely is an impact? Despite the odds, one could come tomorrow.
What would these impacts do to your community? See the results at Purdue U’s Impact Earth website. Even a small impact could devastate it.
What we can do to prepare?
“Find all asteroid threats to human populations and know what to do about them.”
— NASA’s Grand Challenge, 18 June 2013.
The Apollo program did little for America (little more than burning those billions), and the manned space program since then has done less, for one simple reason. We lacked a reason to put people in space. An asteroid or comet will eventually provide the motivation — either to defend against an approaching object or to prevent another one hitting. Arthur C. Clarke describes the latter scenario vividly in Rendezvous with Rama.
We have the technology and money to start building the necessary infrastructure to defend against objects from the sky, among the worst and most easily preventable of the most apocalyptic shockwaves (low probability, high impact disasters). First, by building systems to track objects in the solar system, even those on its outer fringes. Second, by building systems to deflect away large objects.
We can do this slowly and at low cost, if we start soon.
As a great starting point, see this six-article series by Rusty Scheweickart (astronaut, aeronautical engineer, and fighter pilot). To learn about asteroids and the defense against objects from space, see their education page. If you prefer videos, see them here.
For More Information
- Men in space: an expensive trip to nowhere.
- Why we have not gone into space, & why we will.
- Asteroid Day: reminding us of the threat, pushing us out into space.
- Three things to know about asteroids, certain death from the sky (eventually).
Why these objects keep coming to Earth. Why we can’t stop them yet.
The solar system is not in equilibrium. To learn why I recommend the brief and clearly written Newton’s Clock: Chaos in the Solar System by Ivars Peterson.
To understand why the manned space program accomplished so little, beyond the stunt of a few lunar visits (and later the almost useless space station), I recommend Dark Side of the Moon: The Magnificent Madness of the American Lunar Quest.