View My Stats

Friday, June 30, 2006

All our achievements can dissipate, the Indus Valley way

The Indus Valley Civilization is a classical example of an extremely advanced urban meritocracy that had all the signs of leapfrogging into the future, but which instead just dissipated over time as the climate changed.

It shows that the future is not guaranteed, no matter how promising everything looks at any moment in time.

Unless we use the current opportunity to expand beyond Earth soon, we might meet the same fate, and our descendants a few 1000 years later might wonder why we never moved on to the stars. Or worse, they may forget about us. Or there may not be any descendants, and the people examining our ruins might be aliens from a nearby system.

How unimportant can lost greatness become? Interestingly, most people outside India don't seem to have read about the Indus Valley Civilization in their school books, despite it being one of the pinnacles of the ancient era. There may yet come a day when no one will learn about the Apollo missions or the Hubble Space Telescope- if we give up our current chance to reach the stars, and get bogged down in inconsequential bickering.

Imagine where we would be if the Indus Valley Civilization had gone into the industrial age in 3000 BC, over 2000 years before the classical Greek civilization got its chance, 3000 years before the Romans got their chance, and 5000 years before the Europeans finally got their oppurtunity and used it.

There are other examples of lost "almost there" civilizations in human history, but Indus Valley was the first that came so close to the threshold and then dissipated.

Our current "Space Age" is the first threshold towards reaching the stars. Are we going to be one of the many in our galaxy that get this oppurtunity but never quite make it? Don't be so sure of the answer; but it is up to you, me, and all of us to make sure that it does happen!

Thursday, June 15, 2006

Mars: The Foundation for an Interplanetary Civilization

I made a presentation recently to the local Austin Mensa chapter on behalf of the Austin Mars Society. Here is an html version of that presentation online. I suggest going through the whole presentation, in case you are interested to know more about where the future of space exploration is headed. However, do not miss the really nice part about the future of human society beyond Earth that starts from slide 124.

It took me a lot of time to bring this together- I have yet to find a presentation on the web that covers so many issues in combination; it is important that any prediction about the future incorporates the network of events that influence each other, and hence the future. Things do not happen in isolation. If I were to ignore all the non-NASA related changes happening in our World- political, economic and cultural, I would come up with a depressing, quixotic and grossly incorrect estimate of the future of Mars and Space exploration- something that would resemble what many of the traditional American media and this ex-NASA guy have done. Instead, I have tried to imagine what would happen because of these interacting World-changing shifts happening, especially: (1) massive growth in economies of India, China and a resurgent Russia, (2) major and ongoing advances in biotech, robotics, AI, electronics, material science (3) increased private entrepreneurship in space exploration; both manned and unmanned, (4) a revolution in SETI, telescopes and planet discovery that is only going to get bigger because of (2) and, (5) major findings on Mars making it more attractive than we could have ever imagined.

Hope you enjoy the ride! Any feedback is welcome. Click here to start the presentation.

Thursday, April 20, 2006

Dumb & Dumber?

Being an engineer, a researcher and a technologist, I am often surrounded by a multitude of people with the same type of background wherever I go. Some individuals from this group of sucessful people from my age-group (20s and 30s), most of whom have never had to struggle in their life (the way a substantial fraction of humanity is still struggling) like to reason that a large number of people who appear lower-class and "not-so-smart" (such as many of the low-education migrant workers in USA, or the poor and illiterate in India) are somehow denstined to grow up poor and disadvantaged. And I feel a larger fraction of them who don't actually talk about it, probably feel that way privately. I have come across this attitude in multiple places and countries I have worked at; some even hint that the plight of these poor workers or their lack of success might even have something to do with their genetics. I find this attitude almost on the verge of being facism or xenophobia; and such a patronizing attitude comes from people who have never had to struggle in their life- they pretty much got every oppurtunity they could get thanks to their parents/upbringing- all they had to do was play the game to success. These people also point out that for this reason humanity is doomed; its being overtaken by poorer and less smart people who leave more descendants behind.

Whenever I hear such stuff, it makes me feel incensed, and instead of going through a discussion with every such person I come across, I thought this blog might help express what I feel, and perhaps change the mindset of some; if I do succeed in doing so, perhaps that would help make our society a bit more caring, and a bit more united. After all- how can humanity graduate from its womb and expand beyond Earth, if we harbor such selfish and "tribal" viewpoints?

There is a vast amount of scientific, social and historical literature out there that would show that such a class phobia is completely unjustified, but I would try to summarize the point here in a few lines. The question is, is it a less rich (politically correct way of saying it) or a dumber environment which causes people to grow up having a lower standardized IQ and a lower skill job? Perhaps a small amount of brain-speed variation is there on taking an exam that someone is born with, and perhaps there are a few savants and prodigies who are outside the distribution of the general population, but in general, we know now that the environmental factor dominates and not genetics; most of the humans who survived the evolutionary squeeze and near-extinction (when at one time just a few thousand homo sampiens were left behind), were extremely smart, and all of the human beings in the World today are pretty much copies of this small group of super-smart ancestors.

Two things to point out: (1) the social factors for increased intelligence are still at work, and (2) these poor workers are genetically as smart as any of us. Now there is more evidence from orangutans supporting this hypothesis. This should allay any xenophobia less dumb people might have against more dumb people leaving more descendants behind, and at some basic level we are all much more like each other than it may appear superficially; it also points to the amazing plasticity of the human brain. The huge gaps in individuals today are mostly an artifiact of the huge gaps their respective societies historically contained, and which might take another few generations to slowly go away.

This also means that the days of antisocial relics such as N. Korea, Burma and others are numbered; they will either evolve into more socially tolerant (and consequently more intelligent) societies, or will slowly decline into oblivion. Being an optimist, I believe in the former; the most decadent societies of today are still progressive enough, and have enough external World-view filtering in (compared to say 12th century Europe) that their own people will force the countries out of the social (and consequently an intellectual and technological) stagnation they are currently in. This theory also explains why grafting open societies (such as the war in Iraq right now) can at best act as a catalyst (and at worst a failure)- most of the work of building a rich and open society out of a decadent one has to be done by the local people gradually, and would require at least one generation to become self-feeding and stable, even with massive external support (as a younger, smarter and more socially rich generation grows up and takes the reins of the society from their decadent ancestors).

Monday, March 20, 2006

Small Islands in a Vast Ocean: Moon or Mars?

(I wrote this story originally on May 2, 2004)

Imagine you are an alien species that has evolved on a small green island somewhere on a very large planet, whose surface is mostly water with a sprinkle of small islands, most of which are either frozen or blazingly hot, or for some other reason, inhospitable. With recent advances in technology, your species is beginning to discover other islands nearby, and a realization is starting to dawn among the intellectuals in your society that your island is perhaps too good to be true - lush forests with eternal streams of fresh water surround fertile farms that produce plentiful and a wide variety of crops every year. Over the last few centuries, your species has mastered enough technology, and with technological and social advancement, the population of your Island called Earland, has now stabilized to a densely populated but an efficient and culturally enriched civillization. Most individuals of your species are preoccupied with living on this beautiful island, and they do not understand why anyone would look for more space to live.

In spite of these gains, some of your species, including you, are extremely curious, just like your nomadic ancestors who eventually expanded and settled the whole Earland island. You want to find out what other kinds of islands are out there, and if there is anyone like you out there, also wondering about you. You are also worried about the future. Your scientists have found archeological evidence that many other species existed on your island long before your species came along, that have long since vanished without a trace. Evidence has also been found for others that went extinct because of disease, and that at certain prehistorical times, large Tsunamis and volcanic events destroyed virtually all complex life on your island. You believe that all the eggs are in one basket. For your species to survive, a second island is needed as a home.

This is the first time your group is trying to set up a permanent base on another island to save your species from the virtually guaranteed long-term extinction. Not surprisingly, the general lack of awareness among most members of your democratic society has resulted in only small amounts of public resource being allocated for this task, which is a lot less than the amount your society spends on football games. Assuming no major technologicalbreakthrough, for the next 20 years there is only going to be enough money and resource to perhaps explore and settle just one new island. Maybe after 20 years, if you can prove to your society that all the eggs do not have to be in one basket, and that there is really an alternative, they will allocate you more resources for further exploration. If you fail, perhaps the current trickle of funds will also dry up, and perhaps it would be too late for the next Tsunami, the next eruption of the dormant volcano on your island, or the next big plague. With the increasing integration in the recent years of people from various parts of your island, the risk of a disease wiping everyone out has becoming more likely.

Your recently developed telescopes have revealed a nearby island called Marland which is barely habitable, but which can be easily improved within a few decades to become lush and green like your island, and support a large population - it has large amounts of fresh water and land that could be made arable, and is only a bit colder than Earland. In fact there is some evidence of existing and past greenery on it. Discovering these organisms would reveal answers to your own origins. Did you come to Earland from another island, or did you evolve independently.

The other options are extremely hot, cold, or very far away islands that could be habitable - no one even knows for sure that another fertile island exists. It might be 50 to 200 years before your technology will allow visiting one of these farther, potentially habitable islands, and without technology to visit the nearby Marland, such technology will never develop. You will have to develop ships that can travel 10,000 times or more faster than current ships, and then travel to these distant dreamlands over many years. And once you reach there, for all you know it might be already occupied by other people, who may not welcome the colonization effort. You are also scared that they might be having the same ideas. For now, your species is trying to build stronger telescopes to find if there are any other fertile islands at all.

There is also a nearby extremely barren land, called the Moonland, where you can only live inside caves, and it has perhaps a tiny amount of fresh water frozen deep inside one cave. There is no life on this island, and can never be. You enjoy looking at the strange desolate landscape of Moonland from your island; the contrast with the lush greenery around you is bewildering and a bit disorienting. Someone has to be crazy to want to settle down on the Moonland, although there are a few astronomers who would love to be under the clear sky of this dry island. The promising island of Marland is reachable in 6 months with your boats. Now the dumb question is- where should your species go first?


  1. Distant frozen islands. Not reachable for another 50 to 200 years.
  2. Marland: a large island that could be easily made habitable, and that can support a large population. 6 months trip.
  3. Moonland: the barren nearby island that is 2 days trip but has nothing on it. You have explored it before and found nothing too interesting on it, besides a base for astronomy.
  4. Camp in the open sea nearby.


The answer is trivially obvious to you, but unfortunately there is politics involved, and people are still arguing about which island to visit first. Many are not even aware of the differences between the islands' habitability and are clamoring for setting a big camping site on the nearby barren island first, and then trying to grow food in caves by using a complex set of mirrors to get sunlight in. And even more amazingly, there are people who have been camping a few 100 feet out in the Sea for months and years, in open, unprotected boats. It takes them a few minutes to get to this 100-feet-off-the-shore camp, and these campers keep coming ashore for food and your society keeps sending them everything they need, although support has recently been declining after a few fatal accidents in which some people drowned trying to make this back-and-forth trip for more food/relief. This has been going on for over 30 years now, and it has been 35 years since your people last camped on the barren Moonland.

The campers are being funded by many groups in your island, and they claim their camping in the open, nearby water is justified because they are trying to figure out the effects of spending many years in the ocean on members of your species - especially the effect of open sun, wind, and saline water. You try to tell them that we could design enclosed vessels to go to Marland, so they don't have to waste time figuring out the long-term effect of open weather on travellers, but all goes down a deaf ear. Obviously you cannot deprive them of the only argument they have for their existence; a large number of people are employed by your government to keep these camping trips going, and these people are scared of losing their jobs. It is a political hot-button issue, but the utter wastefulness of the whole situation is very evident to exploration-minded people like you. What should you do (besides writing and reading this blog)?

Connection with reality:

I guess at this point, to anybody who is interested in space exploration, it must be clear that this story was a metaphor to demonstrate all sorts of issues with (1) exploration focussed either on low-Earth-orbit, or (2) on the Moon, or (3) no exploration and colonization at all. The large open ocean is our solar system, camping in space is bringing all your consumables along and throwing the unprocessed trash out. The open-camping is worse and corresponds to a space-station with no gravity- it is somewhat trivial to create artificial gravity by spinning a habitat on a long tether with a counterweight on the other end. There are ways to get around radiation problem similarly with just water and fuel surrounding you! The main motivation people give for the space-station is: "We are trying to figure out the long-term effects of zero-gravity and radiation exposure on human beings and how to mitigate it before we can go to Mars!"

Exploration of other places for the sake of exploration is good and I support that, but until we learn to live as a separate colony on the most hospitable planet outside Earth i.e. Mars, it would be pointless to try to develop a base on all the more inhospitable places using more exotic technology. It is equally pointless to camp in space where there are no resources, or to try to design near-100% recyclable systems- if you are on the surface of a planet, the system does not have to be closed, as you can draw in resources (air, water, soil), use it to generate useful materials, and then dump the treated waste out- similar to the process used by responsible but densely populated countries such as Belgium, Germany or Japan (a popular misconception is that US is good at this just because it is a developed country. Ask yourself if you live in USA- how do you dispose off your AA batteries and plastic wastes?).

There are very few locations in our solar system which will support more than just a camping mission in the foreseeable future. One such planet is Mars. It has all the raw resources that Earth has in a readily usable form- water, minerals, soil, air and last but not the least, protection against cosmic rays and solar wind in large areas of the planet (see my earlier blog on this issue). It is the stepping stone to exploring and colonizing the rest of the Universe. That is what all the fuss is about!

The Planetary Society represents the largest public space advocacy group, and it has made an official policy over the last few years that the manned exploration of Mars should be THE next goal for us. Unfortunately, soon after the big Moon-Mars initiative was announced by President Bush in 2004 (which prompted the original version of this story), the implementation got bogged down in petty politics and it has now become mainly a Moon initiative, with a use-and-throw program that provides the capability to camp on the moon for a few days by 2018, with hardware that will be hardly of any use beyond that. Things are already starting to break down as the political support for even the Moon program has started to waver, and the funding is once again not being given to the point needed- NASA is slowly shrinking the Moon program by throwing out critical pieces that would have made the program usable for Mars missions. All this is happening even though the Moon manned program is supposed to be a rehearsal for the eventual colonization of Mars. Tens of billions of dollars are still being wasted on keeping the camping in the low-earth orbit going, in spite of the fact that if this money was diverted on developing systems for a robust and permanent settlement of Mars, we would get the low-earth camping (by 2010) and the Moon-base (by 2012) for almost free, and we would reach Mars by 2016 rather than in 2036 (A date 30 years in the future means that for all you know, it will not happen).

Wednesday, February 08, 2006

Both Robots and Humans needed on Mars

Originally written on May 10, 2004
Updated: Feb 8, 2006

A couple of points before we delve into the details -
  • Point 1: It's not about whether Robots or Humans should explore Mars - Robots and humans will have to work together on Mars to have a productive mission, doing what each one of them are best at doing. Humans with their immense creativity and ability to improvise on-the-spot when things fail. Robots, in their ability to do boring stuff accurately again and again without getting bored or making mistakes, or forgetting (assuming your robot software does not have too many bugs !).
  • Point 2: Often many people don't realize that you cannot do tele-robotics (remote controlled robots) on Mars from Earth. But you CAN do tele-robotics with robots on Mars, if the human operator is also on Mars. Light takes anywhere between a few minutes to half-an-hour for one interactive command from Earth to Mars! This is the reason the robots Spirit and Opportunity sitting on Mars are so slow - their decision makers and controllers are sitting on Earth. And it takes days for the Humans to plan a few seconds of work on Mars, since it cannot be interactive, as opposed to operating a crane or a dump-truck on Earth. Any amount of AI cannot remove the human decision from the loop besides reducing it, unless the robot is as smart as humans. Geologists and biologists need to hold rocks and fossils in their hand to be sure.
  • Point 3: Given 1 and 2, the cost of per unit exploration by robots is significantly more expensive than humans, because of their (lack of) speed, crudeness in mechanical dexterity, and intelligence smaller than a cockroach. The fact that you have team of 100s of people (400 to be precise for the current mission) support 2 tiny robots on Mars just tells you that it will be hard to scale the exploration up. Any improvement in the speed/efficiency/cost of robots also makes the human missions cheaper by the same amount, since more automation will allow people on Mars to spend more time on exploration than maintaining the robots and machinery. The ratio of the cost of the two mission converges not diverges - the human mission costs converge to the robotic mission costs as robots become infinitely as advanced as humans - in such a situation you could let the robots do everything on Earth - design the spaceships, build them and launch them - no PhDs, scientists, engineers or human workers needed! In fact no humans needed! And once you train a single robot to do rocket science, you can make a million copies of it. The additional cost soon approaches zero. Sending a few humans along is practically free, since the food and material consumed by them is being produced by other robots. Contrary to this super-robotic scenario NASA currently spends most of its money paying salary to people to develop the hardware and software (and so does all the other companies in the world)



Here is an email I wrote in response to a well-known "anti-manned-space-exploration" personality. One cool thing about having humans on Mars is that you don't need to have an army of 400 engineers operating one robot on Mars remotely. According to the latest plans, having humans on Mars, 21st century automation (unlike 60s and 70s technology in the Apollo and Space Shuttle), and the minutes of communication lag will lead to a model of "Mission Support" not a "Mission Control" thus requiring a relatively small number of engineers on Earth.

This article also contains some rough cost comparisons I did for humans vs. robots.

Current Human exploration cost: 3,25 million dollars per man-day of exploration. Current Robot exploration cost A (200 times slower than humans): 400 million dollars per man-day !!

Current Robot exploration cost B (10,000 times slower than humans): 20 billion dollars per man-day = 20 billion for one days work ! Wow, even Bill Gates will go bankrupt paying someone like that for 3 days! Note: if Spirit and Oppurtunity survive 4 years with declining productivity these numbers will only change by a factor of 3 or so, still making them super-expensive compared to humans.

Finally, any manned exploration will extensively use robotics and automation to explore Mars enough to answer the big questions. Without humans, you get only "teaser" exploration and high costs per unit work. Humans and robots working together on Mars is the key - as it lowers the cost while still giving us the flexibility and speed of the human brain. Robots can also help prepare a site for human missions without having the humans worry about the preparation. Read Mars Direct and NASA's reference plan (derived from Mars Direct) for more info on how this will work.

Monday, January 16, 2006

100 billion Earthly Super Europas?

Imagine a planet submerged in a permanent night for a human visitor which is you - but a planet far from being dark with glowing streams of lava flowing in many places as you fly over it's surface, violent lightning storms in the sky surrounding each of these massive volcanoes, and the non-stop, cold (but liquid water) rain falling back to the surface all the time. Huge oceans 10s of times deeper than on Earth, and massive watery environments teeming with complex life and giant predators. As you soar higher in the complex, seething atmosphere, you encounter heavy snowfall of a freezing atmosphere falling back to the ground below, only to evaporate back up from the hot surface. And up in the sky on one side of this strange, restless, heaving World, you see something very strange - a third of the sky with no stars, forming a silhouette of a large, dark orb, with flashes of distant lightening that are not coming from this World, but from the mother gas giant. But this World is not so dark for the strange large-eyed beings who live on the surface of this planet - and they see a huge glowing orb in the sky - bathing them in a warm light - for this dark orb, the mother "Sun" still glows in the infra-red light. With a diameter of 16000 km to go around, and a density only 2/3rd of Earth, this planet is heftier than Earth, orbiting a gas-giant 6 times the mass of Jupiter. This world is 8 billion years old, and one of it's intelligent species has been watching us in our own backyard, for over 300 million years since they developed the ability to do so. Their system has been temporarily locked with our passing Sun and they have seen the rise and fall of the dinosaurs. They started receiving the television signals 60 years ago, but from our transmissions and their orbiting super-telescopes, they know we are not looking at them yet. Welcome to this strange but surprisingly earth-like world that is an Earthly Super Europa. We do not see it because we have not tried to look for their transmissions in this dark direction, only 0.6 light-years from our Sun! They have left their dark, water-world and have even spread across the other large "moons" of their system. They have had robotic observatories near Earth for a long time now, and have even sent probes and members of their species into our oceans - environments very comfortable for them.

Here is a description of a drake-like equation
to estimate their numbers in our galaxy. Now let us look at these Mars or bigger planets around dark, mostly Super Gas Giants (since some might form around smaller Saturn sized systems, especially in older, inner regions of the galaxy where the ratio of heavy elements is much larger) that have heavy warm liquid oceans, large amount of hydrothermal tidal heating, and if we believe J. Marvin Herndon, a huge nuclear fission core that has kept the tectonic plates and a strong magnetic field going for billions of years into the present. These planets would be very watery and will have a thin coating of ice on their oceans- and can be considered to be mega versions of Europa, and I theorize on the basis of the potentially large number of brown dwarfs and Super Gas Giants that might be out there, might outnumber terrestrial planets bathed by warm solar radiation. The forms of life that might evolve in such a harsh, changing but also well-protected environment is unimaginable- especially since many such systems would be much older than our Sun. The strong magnetic field of these Super Earth Europas would also protect them from any radiation belt of the mother gas giant (which would actually be quite weak and even absent because these planets are far from any major star). It is important to note that once our Sun dies, Europa and yet undiscovered worlds around gas-giants in or beyond Kuiper belt might continue to remain warm and hospitable just below the surface because of a strong tidal effect supported by their large parent and the accompanying siblings.

Open waters in the dark sky?



Some with tidal effects strong enough might even have localized liquid water surface environments: imagine a moon close to the mass of Earth around a solitary gas giant, say 10 times the mass of Jupiter orbiting it at the same distance as Io is from Jupiter. A large amount of intense radiation from the mother gas giant from the first few million years of their existence can blast off much of the highly volatile gases and material give such a planet a density substantially higher than that of Io or Europa leaving behind a much more Earth like system, with continents, a huge warm ocean, open waters in many regions, and lots of lightening, snow-storms and rain driven by hundreds of active volcanoes distributed on the surface, and the parent somewhat warm gas-giant covering a large part of the sky on one side of the planet. The global ocean would be much larger than that of Earth kept liquid because of tidal heating and a huge amount of tectonic activity, and strong sources of both radiative and heat energy near hundreds of ever erupting volcanoes. A thick atmosphere- perhaps mostly of nitrogen, methane and other gases spewed by the volcanoes. Such large volcanoes would even create small continents. Such a dynamic habitable system full of fresh nutrients would be very suitable for evolution of complex, fast-adapting and perhaps even intelligent life- compared to the much slower changing environment in the oceans of Earth- one argument for why land animals on Earth got smarter faster. On Earth we know of at least one hydrothermal species that uses the volcanic radiation for photosynthesis! It would be such a surreal environment; on many such worlds where the right combination of mass, density and parent gas giant creates an atmospheric pressure not too high; in some warmer volcanic regions a human could scuba dive naked or walk in shirt sleeves on a planet with no Sun! A planet far from being dark with glowing streams of lava dominating the scenery and lighting in many places, massive lightning storms visible both from the atmosphere of the dark gas giant and the local storms brewed by the volcanoes. If such a world does exist in large numbers, the possibilities are just mind-boggling, especially since such worlds can remain habitable for a long time. Even if 1 percent of Super-Europas are so hot, that would count to potentially tens of millions to a billion Worlds. Since the numbers are so unknown, and these worlds can exist in our backyard, it becomes imperative as we develop better infrared and imaging capabilities to try to find such large, dark gas giants in our neighborhood. Another important point is that SETI researchers should perhaps not be surprised if they cannot find a visible source for an apparently alien signal. With Jupiter still radiating (40% more?) a lot more energy than it receives from Sun, an object the size of Jupiter or bigger would still be relatively visible in the infrared, especially if it happens to be within a light-year from Earth. Once we detect such very nearby potential habitats, they should be potential SETI search targets and the first "stars" that robotic probes might be able to reach. But more than that, this idea highlights one important range of habitable worlds that might be as big if not bigger than habitable worlds around visible stars.

Tuesday, January 10, 2006

Big Mars News: Strong Natural Magenetic Sheilds against Solar Wind found on Mars

A major discovery on Mars has suddenly made perhaps the issue of radiation shielding for human explorers on Mars (at least in some major regions of Mars) a non issue, or at least very trivial. Before we discuss the significance of this discovery, let us first review the types of radiation threats faced by any future human Martian explorer:

Types of Radiation Threats


There are three major types of radiation threat faced by any human space traveler:

  • Cosmic rays: very high energy particles that bombard us from all directions, this type of radiation is stopped partially by Earth's atmosphere.
  • Solar Wind: charged, high speed particles are mostly stopped by Earths magnetic field that acts as a natural shield, except when periodically Earth's magnetic field disappears when it flips it's poles, potentially caused by a huge nuclear reactor at it's core (see this Discover issue). For someone standing on the Moon, or any other planet without a magnetic field, when the Sun is not shining on you, there is no Solar Wind hitting you. This type of radiation can deliver lethal doses (large enough doses to severely damage DNA leading to death buy radiation burn or cancer within a few years) to an unprotected astronaut in a very short period of time.

  • Ultraviolet light: Earth's high-altitude atmospheric Ozone provides us some protection against UV; humans still have to watch out for the danger- contrary to a popular misconception, even a substantially dark-skinned person can get a bad sun-burn on a typical sunny day on the beach. Without the Ozone this problem would be much worse. The good news is that the UV light reaching Mars's upper atmosphere is already half of Earth, and there is some Ozone on Mars. Due to the very low density of the atmosphere, currently it is impossible for people to walk on Mars without a spacesuit, so getting a burn because of lying naked on a Martian beach is impossible - you will die because of lack of pressure and oxygen before that. With minor UV shield on their spacesuit face-plates, this type of radiation is really not an issue on Mars. Even greenhouses can be designed to have UV shielded plastics.


Vast naturally magnetic shielded regions found on Mars


It was known before Mars Global Surveyor reached Mars, that Mars lacked a strong magnetic field, and people kept gloating about how the solar wind creates a "sterile super-toxic environment" on the surface of Mars making any surface life impossible, and why unless we solve this issue, this was at least one major unsolved problem for long-term manned missions on the surface of Mars.
Here is an interesting discussion from three years ago posted on Austin Mars Society's mailing list.

Since 1997 Global surveyor has found vast regions of strong magnetic fields on Mars.

The most IMPORTANT piece of detail in this news is that large swath's of Mars have magnetic field with strength comparable to Earth's, thus are likely to provide strong natural protection against Solar Wind to astronauts in these regions of Mars. In fact the fields are so powerful that they actually cause auroras on Mars just like on Earth. This is amazingly good news for mission planners currently planning manned missions to Mars - a solution to a major issue that even we could not have imagined, at least for some regions of Mars :-)

Thursday, January 05, 2006

Titan vs. other Biggies of Jupiter

In our solar system (often called Solar System) Titan is one of the biggest moons, and the only one with a significant atmosphere, and has the largest atmospheric column of ANY terrestrial World. Click here to look at a cool visual comparison with Earth. You can see that thick parts of Titan's atmosphere rise hundreds of kilometers above it's surface.

Here is a nice set of images comparing the relative sizes of some of the other big Moons in our Solar System (note that Venus is almost exactly the size of Earth):