Thursday, February 21, 2013

Space Impacts

What is the value of a space program?

Value is determined by a relationship between what is true of a state of affairs and its consequences and what people desire - combined with a second order evaluation of whether those desires themselves are malleable desires that people have reason to promote or inhibit.

Yesterday, I wrote about the desire-thwarting potential of an asteroid impact.

The main conclusion of yesterday's discussion is that there is a near-certainty of a future impact that it would be worth over $1 trillion to avoid. It is a mistake to think that astronomers are looking at asteroids to answer the question, "Will we get hit?" They are looking at asteroids to answer the question, "Which one will hit us next and when?"

However, the "present value" of avoiding an impact far in the future may be very low. Even if we were mathematically certain of an asteroid impact 1 million years from now, it scarcely warrents a lot of investment today. We are, for example, quite confident in predictions that the earth will be destroyed in about 5 billion years - but that does not justify any sort of panic today.

We will certainly need a space program at some time. It's worth will be in th hundreds of trillions of dollars. But maybe not today.

Yet, asteroid impacts are not the only threats we face from space.

Another is the threat of long period comets - comets whose orbits are measured in tens of thousands of years. Comet Hyukatake was discovered 53 days before passing within 10 million miles of Earth. It may have been discovered 53 days before hitting earth. Here, too, the threats of an impact are exceptionally low, but not zero.

Another potential threat comes from rogue planets. These are planet-sized objects that either formed in space like very small stars, or formed around a star but was ejected into interstellar space by the gravity wars with other planets. Astronomers estimate that there are more rogue planets than stars. They are difficult to see. Furthermore, they do not need to strike the earth to cause significant problems. Their mass would affect all orbits within the solar system. We may have cleaned out our orbital ring to some degree over the past 4.5 billion years, but it will not likely stay clean.

There is also the issue of a near flyby of another star. Fortunately, since stars glow brightly in the dark, they are easier to see. This, in turn, makes it easier to predict any stellar fly-bys. GL710, currently not even visible to the naked eye, will be one of the brightest stars in the sky in 1.4 million years as it passes a little more than 1light year away from the sun. It will have an effect on the Oort Cloud, potentially sending long-period comets into the inner solar system.

Of course, this easily qualifies as "too far in the future to worry about today."

While we are on the subject, I would like to mention another future impact - when the Andromeda galaxy collides with the Milky Way. This will throw the orbit of everything into chaos. This is worth mentioning, not because it justifies taking steps to protect our descendants from this collusion today, but to illustrate an obvious but often overlooked fact about space events compared to terrestrial events. It is a threat we did not even know about 100 years ago.

Space events are potentially very, very large. And the earth is very, very small. No earthquake, super-volcano, hurricane, or winter storm can carry the destructive (desire-thwarting) potential of events in space. Furthermore, the universe, like a lumbering giant in a field of ants, cares nothing about who lives or dies. If we want to survive, it is up to us to determine where the giant will step next and make sure we are not standing where it happens to be stepping.

The way we do that is with a space program.

This is at least some of the value of a space program.


Unknown said...

Alonzo, yes! This Aristotelian- Epicurean, utilitarian/ consequentialist, neo-Kantian, moral realist perforce finds the space program necessary.
Would you deal with the introduction to Herbert Spencer's Social Statics? Social Spencerism [ not Social Darwinism; Spencer- Randism] leads to the road to serfdom, whilst liberal capitalism is the known practical moral ideal!

Anonymous said...

And I agree with Peter Singer's desirism, under another term, to abolish world poverty. I hope that people will follow his and Jeffrey Sach's suggestions to do so.