Monday, November 24, 2008

The great Canadian fireball of 2008

At approximately 5:31 PM local time last Thursday, residents of Edmonton Alberta got a bit of a fright. The skies lit up over much of central Canada as a large fireball streaked across the heavens, flaring and fragmenting, seemingly striking somewhere over the horizon. It startled a number of residents and was inadvertently caught on surveillance cameras at several locations (a google search will reveal a number of these). While it hasn't been definitively identified, it was NOT: A. the lost tool bag from the international space station, or B. a crashing UFO. It was most likely a nickel iron or stony meteorite ranging in size from an orange to a small desk which broke up as it entered the atmosphere The breakup resulted from the overpressure which results from the force exerted on the meteor by air pushed ahead of it that can no longer get out of its way due to its great speed (around 17 kilometers per second) It was an amazing albeit somewhat rare event, which scientists term a bollide, and count yourself lucky if you ever get to see one (a small one at least) I witnessed one in my lifetime, on new years 1973, over central Florida, around 1:30 AM. It was bright, beautiful, and scary, it lit the sky up with pink, white and green light.
The Canadian event when witnessed on video is stunning, and one wonders if this is the effect of a small meteor what would the effect of a larger one, one large enough to strike the surface with considerable force be? I decided to do just that, using the University of Arizona's asteroid impact effects calculator, available online at The object I modelled for my hypothetical hit was a really nasty one, an iron asteroid approximately 2 miles in diameter, coming in at around the typical speed of 17 kilometers per second, and at at a rather steep 45 degree angle and striking the Edmonton metropolitan area.
The results of such an impact are not suprisedly, total destruction.
A fireball of superheated gas and vaporized rock with a diameter of 8 miles would be created, lingering for approximately 16 minutes, and incinerating anyone or anything unlucky enough to be in its general vicinity. when the fireball dissipated,the excavated crater with a diameter of around 40 miles would become visible, completely obliterating Edmonton.
Then I wondered what the effects would be some distance away, Say, Seattle Washington, around 500 miles away from the impact. Again, even at some distance, the level of destruction is almost surreal. Around 3 minutes after the impact in Canada, the people of Seattle would experience a magnitude 9.4 earthquake, the seismic shock wave caused by the impact ( the fault induced great San Fransisco Earthquake of 1906 was estimated at 7.8) causing severe structural damage all buildings . Around 8 minutes after the impact, material ejected by the formation of the crater would start to rain from the sky, most probably semi molten fragments of rock and dust , which would start numerous fires. As the before mentioned earthquake would probably destroy most plumbing,and thus water pipes, the fires would be difficult if not impossible to extinguish. 45 minutes after the impact, the air blast would hit, with a hurricane level wind velocity of around 200 mph, blowing down 90 percent of the trees, shattering windows and knocking down whatever buildings left standing. The sound of the impact from 500 miles away would be around 93 decibels . Loss of life would be great. It would be the most catastrophic event in human history. And this level of destruction would extend out in all directions for thousands of miles, as the seismic wave and ejecta propagate out from the impact point.
How likely is this to happen? A 2 mile asteroid striking our planet is fortunately a very rare event, happening on the order of tens of millions of years.But it has occurred throughout the history of our planet and will continue to do so The number of people worldwide searching for these objects is the same as the crew of one McDonald's restaurant, and the amount of money allocated for searching is minuscule. But it is a threat, and if it does happen, the only hope we would have of averting it is to get as much warning time as possible, if the asteroid is detected early enough, we might have decades to react, and there that could be developed that could theoretically deflect an asteroid from its path (blowing it up would only turn it from one impact into multiple ones) Hopefully we will see more money thrown at detection in the future. And hopefully we will get more warning time then the Canadians did on Thursday.

Tuesday, November 11, 2008

Dr Doom, intelligent cockroaches and the permutations of Mercury

I saw the asteroid induced Tsunami a long time before Deep impact. I used to think of what would happen if a 1 km asteroid hit the gulf of Mexico, and I used to imagine the wave as it hit the coast, which invariably gave me the shivers. I had the great fortune, or misfortune if you like, of being fascinated by doomsday scenarios. And I still have it, I gawk at a falling stock market, hurricane, earthquake, volcanic eruption. Anything will do. Most people who have noticed this about me have given me the nickname "Dr Doom", its stuck with me for a long time and the same nickname has resurfaced from totally different people over the years. At the age of 15, I convinced my sister that a comet was going to hit the earth on March 24th of that year, and she was somewhat unsettled by it.But felt bad for the deception, owned up, and of course we are still here. So at any rate, I liked Deep Impact, even though it was filled with some pretty damning inaccuracies. For one thing blowing the comet to kingdom come so close to Earth would not have helped, the myriad fragments would have incinerated in the atmosphere with pretty much the same kinetic energy, only spread out over a much wider area, and probably generating enough heat in the process to broil anyone unfortunate to witness it. And Disney's Armageddon, lets not even go there, I guess the special effects guys thought giving the asteroid the appearance of a rock that looked like lava rock from your gas grill was scarier than showing what most if not all asteroids look like; a potato with craters. A spud the size of Texas lumbering towards your planet to cause an extinction level event WOULD have been scary, but maybe a little less dramatic. I guess its the same logic that all spaceships in space movies must make a sound as they move through space (save 2001), its more fun I suppose.
At any rate, I often wondered, what would be the creme De la creme of disasters? That question has been answered without a doubt, by two independent research studies from the Paris observatory and the University of California, which has shown in computer simulations, that over the course of the next 3 billion years, its just remotely possible (the estimation is 1 percent chance) that the gravitational influence of Jupiter on the planet Mercury could cause its orbit to change enough to bring it into more extreme gravitational interactions and possibly a collision with either the Sun, Venus, or the Earth. Or it could be thrown out of the solar system altogether. And don't plan on moving to Mars to escape the mayhem, another simulation has Mars being slingshot out into interstellar space. It seems our solar system isn't quite as tranquil a place as we have imagined it.
To be sure, a collision between Earth and Mercury will ruin your weekend, not to mention completely destroy every living thing on the planet. But don't lose any sleep, the earliest this is theorized to happen is on the order of 40+ million years from now, assuming it happens at all. And since most species go extinct in a much shorter period of time, its more likely we will be absent from the scene when it happens. Of course there might still be intelligent life on Earth then, cockroaches have of course been around since the dinosaurs, and they are pretty tough little guys. Maybe over the course of the next 3 billion years, they will evolve intelligence, and develop a way to save the planet. Maybe that's a real stretch, but when you consider that only 65 million years ago, our ancestors were the size of a small shrew with comparable intelligence, so maybe the roaches can pull it off in 3 billion. their cousins, the termites, already have a sophisticated social order and elaborate architecture. So maybe in the far future, intelligent insect descendants of cockroaches will develop the super science needed to avert the Mercury Earth collision. Think about that the next time you take off your shoe to flatten one. Happy trails.

Thursday, November 6, 2008

UFOs:negatives and positives

OK,the negatives first. I am VERY skeptical about UFOs. First, video cameras have been around for a couple of decades now, but for some reason, no one has been able to film a sharp well defined image of a structured craft. Its always fuzzy, or a white dot moving in the dark sky, or something that could easily be an airplane, star, helicopter, balloon, bird or hoax. Lets not forget hoaxes. Remember ET buzzing Haiti a few months back? That one took me hook line and sinker for a day or two. But alas, it was not to be. CGI is getting pretty damn good. Its going to make identifying a video of an actual authentic UFO allot more difficult I fear. And though I am skeptical, its something I would LOVE to be true. I have been keeping an eye out for UFOs for around 4 decades now, scanning the sky since the early '70s when I used to spend most of my evenings in the small rural town on the west coast of Florida I lived in with outside with my telescope, looking at stars and planets. It was pretty much an every evening thing for around 22 years, to the degree I got the nickname "spaceman" and only twice in that period of time did I see anything I could call unusual. The first "sighting" occurred around dusk as I was setting up for an evening of observing. I saw a little tailless "shooting star sort of skipping across the evening sky. Watching it streak south, I suddenly noticed two other shooting stars behind it, forming roughly an equilateral triangle. The whole sighting lasted about 5 seconds. I was speechless. Then after a few minutes of contemplation, I realized that the UFOS were headed in the general direction of Mcdill air force base, to the south. What I had probably seen was a group of F16s at very high altitude. I didn't give it another thought because I knew that was exactly what I had seen. The second sighting occurred many years later, again at dusk. This time, I saw something extremely weird. It was a slowly moving star like object, at obviously great altitude, that was was in a sort of slow pulsation of brightening and dimming, it would get fairly bright, then dim out almost to non visibility. It was like no aircraft I had ever seen, actually unlike anything I had ever seen. This time, my heart pounding in my chest, I was thinking this could be the actual article, an alien spacecraft. Then again, a little bit of reasoning set in, and I started to put it together. Moving slowly from west to east at high altitude, sounds like, a SATELLITE. The light curve was curious, brightening, dimming, brightening, unless, it was, TUMBLING. I went in the house and yahoo ed "tumbling satellite" Sure enough, there was a tumbling satellite mentioned, launched by Japan, that lost control once in orbit and started to cartwheel. A check of its orbital position on another site had positioned it exactly over my location at the time of my observation. So no alien ship, no greys scouting my neighborhood. The two experiences have made me even more skeptical of the sightings of other people. Being an amateur astronomer I had some degree of familiarity with the sky and objects in it. But when people who very infrequently study the sky and look up and see something they don't recognize, they can be easily fooled. I once had to nearly smack a neighbor across the face to convince him that he was looking at the planet Venus , which he was absolutely certain was moving in a little circle in the sky. The mind can play tricks on us. Then there is the whole "alien abduction" thing. I have two basic observations to make about it. One, Why hasn't anyone ever "observed" an abduction from an adjacent house? You would think if a large glowing craft was hovering over the neighborhood in the middle of the night and our buddies the greys were tractor beaming up Mrs Smith in her nightgown, someone, maybe an insomniac or the garbage man making an early run, might have spotted it going down. As far as I know there are no accounts of this. Secondly, accounts of alien abduction and sleep paralysis are just too close in description to be coincidence, and since most of the abductions I have ever read about happen at night, I am willing to bet they are one and the same. Lastly, the shear number of people claiming to have been abducted should mean that you should be able to look out your window any time at night and see saucers whizzing overhead (Carl Sagan pointed this out). Yet this writer hasn't seen this. Yes they may be knocking out the neighbors and using a cloaking device, but I kinda doubt it.
OK, now the positives. Certainly, the universe is teeming with life. We are discovering extra solar planets at the rate of a few a year now, and some systems even have a similar structure to our own. So I don't think its impossible that someone could be visiting us. The universe is very old, and they may have been watching us for a very long time. The best case for the existence of UFOs I think, comes from sightings by experienced professionals who are very familiar with aircraft and astronomical phenomena; pilots. There have been scores of sightings over the years by pilots that are not so easily explained away by other aircraft or tumbling satellites. These guys are familiar with both, so when they see something they care to call a UFO, you can pretty much rest assured its something unidentified. The same thing goes to a lesser degree to law enforcement, they are trained to be good observers so they are also not easily fooled. Lastly, some astronauts are starting to come forward with some amazing accounts of sightings in space. The Apollo 11 astronauts had a sighting between the earth and the moon that has never been explained. Apparently, they HAVE seen things out there. I will close on this note. UFOs are no more improbable than a primate evolving over 3.5 billion years on a rock ball orbiting a little yellow star on the edge of a spiral galaxy. And I cross my fingers that Keanu Reeves gets "The day the Earth stood still" right. Look to the skies.

Saturday, November 1, 2008

My take on Mars one way.

For a few years now, various people have postulated that possibly the best way to send a manned mission to Mars is to do away with the idea of a return to Earth, to literally go to Mars and stay there. It does away with design costs associated with having to create an entire return to earth architecture for the mission. I personally do not think it is a bad idea, for lots of reasons, but there are some major obstacles to be overcome. First, before we send a team there, we need to know a great deal more about surface conditions on Mars. There may be some extremely toxic chemical compounds there due to a different surface chemistry and surface materials reacting to Ultraviolet light which pretty much beats down on the surface worse than any bad day on the beach that you ever had. There is also the very real possibility that some form of microbial life might exist there. My gut feeling is that any life on Mars will of course be extremely tough and hardy, able to exist on not very much, and there is a possibility, albeit remote, that it might sense a human being as a very target rich environment for raw materials. Think Andromeda Strain. Older readers who remember the Viking missions might recall a very strong reaction in some of the experiments searching for life (which was later attributed to exotic Martian soil chemistry, there is still an argument about it.) We really have to conclusively establish whether or not microbes are existing at least on the surface, and if so, do they present a threat to our astronauts? If microbes do exist, we also need to establish how much of a threat we may represent to them. One celled or not, it is their planet. Then there is also the problem of contaminating Mars with Earth microbes. On a relatively short duration surface stay, it could be argued that precautions could be taken to keep Mars uncontaminated by Earth bacteria. But if an individual or groups are going there to stay, it may be much more difficult to achieve.
Then there is the entire issue of how to construct a base camp. Probably the best way to do it would be to bring the base camp with you in the form of the landing craft. We could also send up supplies on a periodic basis. That aspect of a project is a problem, as its not easy to precision land something on Mars. There is no magnetic field that will allow a compass to work, we presently don't have a GPS system for Mars, so navigating a spacecraft to a precise point on the surface is not going to be easy. In other words, your care package from Earth could land a few hundred miles away from you. We would need some kind of reliable ROV (remotely operated vehicle) to go fetch it for us. Or we will need some reliable surface or air vehicle to do it our self. It some point the camp might be able to become self sustained, indeed that should be a primary goal, but it might take time so resupply would be needed. And to be sure an added benefit of resupply from Earth would be the psychological effect of still being connected in some way to the mother planet. And make no mistake, being on Mars and knowing you are there to stay would be a psychological Mount Everest to climb. I am sure there are multitudes of people who are going to be up to the task, but since it is something beyond human experience, there is no real way to tell how a human being would deal with it. We have some experience with isolation in places like Antarctica and in space, but those people knew they had at least the possibility of return to civilization, and these explorers will have a much slimmer chance, the only possibility will come from Earth. So I believe that's going to be a monumental challenge.
Also, the equipment we take is going to have to be orders of magnitude better than anything we have used. Since spare parts are going to be several hundred million miles away, things like space suits and life support systems are going to have to operate flawlessly, and will have to be redundant on at least a factor of 3. A space suit that can operate for days on the surface instead of just brief forays from the shelter would be a good start. a portable inflatable habitat module would allow extended surface exploration, you could step inside the thing, inflate it, and at least have a survivable environment.
I also do think that the idea of sending just ONE person is foolhardy. One person who falls and breaks a leg is going to be dead. Not to mention a million other things that could happen. It would also be better to have several pairs of eyes and several brains there to observe and experience. Then there is the obvious psychological benefit of not being alone.
At any rate, the idea of a one way mission is not something we should discard for some moral discomfort. Humans have been going on one way explorations as long as there have been humans. Think where we would be if we didn't have this in us.