Monday, September 27, 2010

Life on Mars

The 9 to 5 has prevented me from hitting full throttle on my blogging endeavours the last few months.  I may finally have struck a balance between work and blogging.  Over the next few months, I am going to write a number of posts on my favourite topic: The Universe.

To start, let's look at the possibility of life on Mars.  The red planet has long been suggested as the next best rock in our Solar System to host life.  By that, I am not suggesting human-like Martians that you see on TV or the big screen (as this famous Martian image alludes). Instead it is quite likely that simple organisms might have existed back when Mars was more Earth-like. Here are some engaging arguments: 
  • Mars water-scarred terrain - the planet has vast systems of canyons.  In fact, the "Grand Canyon" of Mars is 5 times longer and 4 times deeper than the one in the U.S. These rugged terrains suggest the forces of water and glacial ice once at work. Needless to say, water is a key breeding ground and ingredient for life.  
  • Past existence of a rich atmosphere - Mars used to have a rich atmosphere which meant that it could sustain large bodies of water on the planet surface. As the atmosphere slowly disappeared however, so did the surface water. 
    • Abundance of carbon in polar ice caps - The polar ice caps on Mars contain large traces of dry ice. This means the planet also has a carbon store, the other ingredient known to all life. 
    • Mars was once geologically active - Mars' Olympus Mons is the largest  volcano in the solar system.  It is as tall as Mount Everest and as wide as Hawaii.  Although the volcano is now dead, it was once believed to be fiercely active. Why is this relevant?  A planet active in volcanic activities circulates the necessary minerals and nutrients to form life. 
    • Magnetic chains from Martian meteorites - Back in 2001, a four billion year old meteorite from Mars was found to contain microscopic magnetic crystals. The telltale crystals were arranged in long chains, which scientists concluded could only have formed by once-living organisms. Similar microbes currently exist in Earth's oceans, and the magnetic chains they produce are used for orientation relative to the planet's magnetic field. Could such microbes have existed in Mars? We know that Mars no longer has a planet wide magnetic field, but evidence from ancient rocks suggest a whole different picture billions of years ago. 
    • Discovery of methane from Mars - In 2003, large plumes of methane was discovered in the northern hemisphere of Mars. Normally, methane breaks down quickly under Martian conditions. The fact that these plumes exist in continual abundance suggests the planet is still geologically or biologically active. Some organisms release methane when digesting nutrients. Oxidation of iron however can also release methane. Indeed, the rusty crust is what gave Mars its nickname.
    The list of pro-Martian-life arguments can go on for a while. Where would life be if it were to exist on Mars? It is now widely believed that any life forms on the planet may be confined deep underneath the crust, where it is still warm enough for liquid water to exist.  After all, the ape-like figure in the image is nothing more but a pile of Martian rocks. 


    Saturday, September 4, 2010

    Earthquake in New Zealand

    New Zealand is still dear to my heart since my visit in April.  Therefore, it was shock to see in the news that a magnitude 7.4 earthquake struck Christchurch early this morning.  Miraculously, no fatalities or injuries were reported so that is great news! Hope the residents there can get back on their feet quickly and rebuild the city.


    Thursday, September 2, 2010

    Evolution in Action

    A recent study on evolution is shining the spotlight on the three-toed Australian skink. When it comes to reproducing, some skinks are foregoing egg laying by giving birth to live youngs. Apparently, lizards living in the warm lowlands of New South Wales (NSW) are literally putting all their eggs in one basket, while their colder mountain dwelling neighbours are favouring live births. Various species of reptiles were known to have made such transitions in the past.  Not often do you catch them in action however. 

    What are the pros and cons of each reproduction method? Egg laying is a less taxing feat on the mother as she does not have to carry embryos. The caveat is a tantalizingly high mortality rate.  As for live births, the fetus has a shelter for development at the expense of the mother.

    This is certainly an interesting discovery, especially when the lizards are literally living in my backyard here in NSW!