Archive for astronomy

What’s This About Methane On Mars!?

Posted in astronomy, biology, personal views with tags , , on May 6, 2010 by cpolsonb

I have had at least a few people ask me directly “what exciting stuff is there left to discover in science?” Other than the obvious fact that there are definitely exciting answers to questions we haven’t even conceived of yet, there are also many major scientific mysteries answerable in this lifetime. I do not look think badly of these people, they likely haven’t had the exposure to learn about cutting edge modern scientific mysteries. It is also true that many of these mysteries, like those potentially answered by the LHC, require a deal of background knowledge to wrap your mind around. Nevertheless a few hours on wikipedia browsing major concepts in physics and astronomy is all anyone needs to appreciate the awesomeness of things like black holes, dark matter, entanglement, supernovae, exo-planets or the Higgs Boson.

This blog entry is about what I consider possibly the most exciting scientific question easily answerable in my lifetime. That question is “What’s with the methane on Mars!?”

What is so exciting about some gas leaking from Mars you might ask? First a little background. Methane on Mars was first discovered by a team at NASA back in 2003 using infrared telescopes fitted with spectrometry devices that break down incoming light into it’s constituent spectrum and can infer chemical composition from the signature or absorbed wavelength. This methane is being released annually (Martian annual) during the warmer periods at a number of locations. The gas is released in a series of plumes which can release as much as 19,000 tons of methane each!

So what does this all mean? Well we begin by considering all possible explanations for these methane plumes that scientists consider plausible. A likely explanation is that some geologic process is going on underneath Mars that is creating this methane. The only known way this could be happening on Mars is if water, carbon dioxide and the planet’s internal heat are converting iron oxide (rust) into serpentine minerals (common rock-forming hydrous magnesium iron phyllosilicate minerals). One major stumbling block with this explanation is that Mars is not thought to be geologically active and the required heat has not yet been found. It is possible that pockets of methane created in aeons past are stored beneath the surface and released annually as fissures form from cracking permafrost but this adds in another layer of complexity. There are other geologic questions that need to be answered before a complete explanation could be established and any such answer would still provide fascinating and as yet unknown information about ongoing activity on the Red Planet previously not thought to exist.

Another explanation, recently discounted by published research suggested that the methane might be left over on Mars from meteorites. Calculations have shown that the amount of meteorites needed to continually maintain the levels of methane found on Mars is far beyond what could be considered possible. There are other gaping holes in this hypothesis, such as why would the methane be confined to a few discrete pockets and why is it only being released annually. After considering the possible explanation of geologic activity and the unlikely explanation of meteoric activity we are left with one other major hypothesis.

LIFE!
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An Exciting Observation

Posted in astronomy, Trips and Visits with tags , , , , on February 26, 2010 by cpolsonb

A few weeks ago on Saturday February 13th my girlfriend and I experienced a “star viewing” night at the Perth Observatory. I wasn’t sure exactly what to expect and hadn’t previously been to the observatory since I was around 8 years old! I was extremely excited to go again, just seeing a night sky without the depressing light pollution around the metropolitan area would be exciting enough to satisfy me. But boy was I blown away! It truly was one of the most enjoyable nights I’ve had in a long time. Whilst quite brief (around 90 minutes) the whole thing left me drooling for more. During the viewing night I was madly scribbling notes down in my girlfriend’s diary (in pitch black) for fear of forgetting something. I’ll quickly give a run on the history of Perth Observatory and what is involved in their viewing nights.

A Little History
Perth Observatory is actually Australia’s oldest continually running Observatory. First built near to Kings Park (a large park near to the capital) in 1897 the construction of the observatory heralded a long lasting era of astronomical research and discovery. Aside from the scientific importance the completion of the observatory also meant that Perth at long last could accurately measure the time! The Observatory stayed at that location until it was moved (due to light pollution) in 1966 to its current location in the foothills at Bickley. Unfortunately even this move was not sufficient to properly shield the heavens from light pollution and there is an unfortunate loss of clarity in the Western portion of the sky.

The Viewing Night
Arranging the viewing night was a quick and painless affair. At the cost of a meal ($20) you can easily book yourself in with a single phone call. Once there you are greeted by the warm and experienced staff, all astronomers with at least a decade experience. After a brief history lesson in the observatory’s museum including a look at some real life asteroids and amazing sky photos taken locally, you are quickly whisked off up to the telescopes. It’s a quick walk up a path with strip lights to guide your way (which switch off once you’ve arrived) and very quickly you’re standing amongst the viewing scopes.

A quick introduction to the night sky ensues (with the help of a visible laser pointer) and such objects as Mars, The large and small magellanic clouds, the brightest stars (Sirius taking the cake) and of course the beautiful milky way itself! Seeing the thick arch of stars that is our arm of the milky way stretched out above you like a backbone holding up the sky is an amazing sight which is completely invisible inside the metropolitan area. I envy greatly those of you who live in areas where this is a common sight. I dare say that many Australians aren’t even aware that the milky way even forms this band across the sky.

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