Apophis

Apophis

Astronauts talking from the movie Deep Impact...
Mark: How do we set the nukes inside the comet and get out before they blow?
Orin Monash: We don't.
Andrea: Look on the bright side. We'll all have high schools named after us.

One of the open questions in science is, "Where are all the aliens?"  Given the immense number of stars and all the planets we are busily detecting, it just does not make sense that we are alone. There are four popular theories that I know of:

1. Stay hidden or else the militaristic aliens will get you
2. Intelligent machines eventually take over each planet
3. Periodic supernova sterilize regions of galaxies
4. Civilization is wiped out by a meteor impact

We know that Earth has been hit by meteors in the past - some of them were pretty big as in Arizona and the Yucatan. NASA takes seriously the chance that it will happen again by tracking the path of all known asteroids.

Presently all eyes are on asteroid, Apophis. In 2004, NASA scientists announced that Apophis, an asteroid larger than two football fields, could possibly smash into Earth in 2029. After taking more measurements, NASA decided that Apophis will pass by the Earth on April 13, 2029 at a distance of five earth widths. Very close! The moon is about 30 earth widths away.

This year Russian scientists have predicted that the 2029 fly-by will alter the orbit of Apophis in such a way that it will collide with Earth in 2036. NASA is not convinced. They put the odds of this happening at 1 in 250,000. About the same odds as a person being hit by lightening in a given year. (Though I have seen various odds for lightening 1/250K, 1/500K, 1/750K per year per person.)

Bottom Line

You can bet that when Apophis makes its next fly-by in late 2012 it will be extensively observed with ground-based telescopes and radars. If improved calculations put it on a destructive path, NASA will have 24 years to find a way to alter the asteroid’s orbit. Unlike the movies, blowing it up with nuclear bombs is not a good solution - this just changes the impact from one big rock to many smaller rocks. The best hope is to nudge it or push it into a safe orbit.

Truth is stranger than fiction

“Space flights are merely an escape, a fleeing away from oneself, because it is easier to go to Mars or to the moon than it is to penetrate one's own being” - Carl Jung

Here are two pictures from one of my favorite websites, Astronomy Picture of the Day. What is it about orbiting particles that they flatten out and form a disk? Consider the solar system - the planets, asteroids, and most comets all lie in the same flat plane aligned with the equator of the sun. Why not spin about the sun at all angles? Two other examples are easier to visualize. The rings of Saturn are very thin as show in this photo. Note also the cool shadow of the rings on the planet.

Here's a photo of a distant galaxy that we see exactly on edge instead of the typical view from above with spirals. Observe how thin the galaxy is with a thin ribbon of bright stars.

Bottom Line

In college I studied mathematics up to a Doctoral Candidate level. (I did not complete a thesis, though I tried twice over two years. Both times another university disproved what I was asked to prove by my advisor.)  And yet the hardest "math" classes I attended were physics classes. One class used tensor (i.e. 3-D) calculus to study the curvature of space about black holes. Reality can get very weird when gravity and spinning are combined.

Last night I saw a film clip of the famous physicist, Richard Feynman, who was asked "why" magnets push on each other. He said he could not explain it unless you already had a solid grounding of physics. Not because he was a poor teacher but because the magnetic force is so fundamentally an aspect of the universe that there was nothing to compare it to as an example. One could compare it to the push/pull of the electrical force but physicists now know that magnets and electricity are the same force so this is merely comparing magnets to itself. He could over-simplify and say the force was like rubber bands. But then if you were to ask him why rubber bands snap back he'd have to admit that, at the lowest level, it was the electrical force behind the pull so we're back to explaining in circles.

This reminds me of the conundrum, how do you explain the taste of salt? What can you compare it to? 

Often we paint Science and Religion as opposites but as Feynman observed, science is built upon basic principles, statements of reality that must be accepted in order to work at higher levels of reality. One could think of these principles as a type of "faith". For example, do we really know that quarks exist? By theory they can never be observed in isolation only through their interaction. How different is this from Faith when defined as belief in something unseen (but felt)? Believers will say they have felt the interaction of God.

I was going to appease scientists by saying that Science differs from Religion in that the fundamental principles change over time as we learn more about reality through experiments and observations. We no longer believe that everything is made of earth, fire, air and water. We've moved from a particle theory of atoms to wave-particle duality. There is some evidence that the physical constants of the universe may not be constant after all but change over time or space. Scientists see themselves as willing to change theories when presented with the "facts".

But what is truth? Science, like Religion, can be influenced by majority opinions - is global warming real? If real is it man made? Scientists argue over this just like theologians with conflicting evidence and with as much venom and anger and emotions. Is string theory real? Is the universe 11 dimensions? What exactly is gravity? We don't really know how the universe works at its lowest levels but one can pick a theory and choose to believe it. Much like picking a Church to follow with its own unique rules and explanations for reality.

I'm ready for my closeup

“Shoot for the moon and if you miss you will still be among the stars.” - Les Brown

On Nov 4th NASA's Deep Impact space probe visited the nucleus of   comet Hartley 2. This was the 5th time in history a probe has visited a comet.

Bottom Line

This photo was taken at a distance of 700 kilometres of a comet which is only 1.5 kilometres across. This is equivalent to photographing a person from over a half mile away. That quite a telephoto lens!

When Asteroids Attack

“Noise proves nothing. Often a hen who has merely laid an egg cackles as if she laid an asteroid.” - Mark Twain

An article at NewScientist.com, Asteroid attack: Putting Earth's defences to the test, describes a day-long test by the US Air Force in December of last year to test its readiness in the case of an asteroid impact. The US Air Force brought together scientists, military officers and emergency-response officials for the first time to assess the nation's ability to cope with an asteroid striking the Earth in just three days. The exercise was a wake-up call for the Air Force: there is no plan for what to do, the early-warning systems are woefully inadequate, and was no formal coordination between major parties like the Air Force, Homeland Security and NASA.

So it is not unreasonable to ask, should we panic? The answer is no. The best known impact in modern times was a comet 30 to 50 meters across that exploded over Tunguska, Siberia, in 1908, flattening trees for dozens of kilometres all around. The chance of a similar impact is about 1 in 500 each year, or a 10% chance of an impact in the next 50 years. The odds of a dinosaur killing, giant asteroid are much, much lower. But let’s assume you beat the odds and the next small comet or asteroid hits in your lifetime. Well the earth is a very big place with 70% of it covered in water. NASA used to fear that an ocean impact would create giant city-swamping tidal waves but recent research shows that the waves will lose energy before hitting land. (Unless the comet hits close to shore.)

What would an asteroid impact look like? A lot like an atom bomb. The heat of entry will cause the rock or comet to explode in a bright flash of light with a huge pressure and heat wave 30 seconds after. The only difference will be a lack of radiation. Since an asteroid and nuclear bomb are so similar, NASA warned the world when it calculated that a car sized asteroid would hit somewhere in the Middle East last year. They did not want a World War started because an Arab nation thought it had been nuked. Fortunately 2008 TC3 exploded over an unpopulated desert area of northern Sudan and never reached the ground.

Bottom Line

To its credit NASA was able to predict where and to the minute when the 2008 TC3 asteroid hit. To our shame, we had just 20 hours warning of this particular asteroid. And we were lucky to have spotted it at all. Our telescopes are blind to objects moving at us from the direction of the sun or even the moon. Two of the world's three leading asteroid detecting telescopes are based in Arizona, a region that clouds over between July and September.

Get Out Of Dodge

“The evacuation of major cities - we have a problem with that. We've never done that before.” ~ Henry Renteria, Director of the California Governor's Office of Emergency Services

About a year ago I wrote about the acronym TEOTWAWKI. Just this morning I came across another acronym G.O.O.D. that ties nicely into an article at NewScientist.com, Asteroid attack: Putting Earth's defences to the test. GOOD stands for “Get Out Of Dodge” and refers to emergency evacuation planning. When a hurricane is bearing down or an asteroid is about to strike your town, you won’t be the only one trying to escape. I recommend the movie, Deep Impact, which has a scene near the end of a crowded highway, no one’s moving, the asteroid is coming, so naturally people start panicking and driving on the grass, getting into accidents and getting into fights. Every man for himself!

The best solution to GOOD is getting out quickly, before the rest of the public jams the roads. If your go-kits are packed and ready you can get a head start on the crowd. Do not delay. Do not think you can escape “last minute”. You might also want to fill a gas can immediately because stations along the escape routes will quickly sell out.

When evacuating millions of people, I suspect every option is a lose-lose scenario. The highways will jam. Secondary roads can become closed with a single accident. If you have an AWD vehicle you could try off-road driving but have to cope with fences, ditches, streams, etc. In all cases a GPS unit can help provide alternative routes if you get stuck.

Bottom Line

Because of the hazards of evacuation, sheltering at home is often a better choice if you’re well stocked and prepared. But sometimes (killer hurricane or asteroid) you must get out of town, no choice. What will you do?