Mars: Waterworld or Dune?

Biochemist_articleThere’s an old email that’s been doing the rounds for a while now, proclaiming that water has been found on Mars. The attached image double‑clicks open to show a glass of water smartly balanced atop a Mars chocolate bar. Very droll, but this humour does hint at a fundamental question that planetary scientists have been asking about the red planet for decades. What is the prevalence and history of water on the surface of Mars? And more importantly, at least in terms of the biological potential of the planet, what is the story of liquid water: the state necessary to sustain and support life as we know it. Has Mars ever been a Waterworld, with long‑standing lakes, seas and perhaps even a great northern ocean, or has the red planet forever been a desert, like Frank Herbert’s science‑fiction creation, Arrakis, the Dune planet?

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Space bugs!

Space_bugsOn Earth, microbes get absolutely everywhere. Indeed, there seem to be very few completely sterile natural environments. But what about microbial colonization of locations beyond Earth? In this article we’ll explore the realm of space bugs. There is a great deal of interest in the microbiology of the closed artificial environments created for human exploration of the cosmos, such as the International Space Station (ISS), as well as in minimizing the risks of inadvertently transporting terrestrial contamination elsewhere, and even the possibility of a natural mechanism spraying life between worlds over the history of the solar system.

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Matrix: Simulating the world Part II: cellular automata

Matrix2In the first part of Simulating the World we saw how simple mathematical models can be built to study everything from the flocking of birds to the collision of entire galaxies. In these examples, a matrix, or a grid of numbers, was used as a convenient way of storing information on all the objects included in the simulation, so that it can be updated each time step as the simulation progresses. In this second article, we’ll take a look at another class of mathematical models; ones where the matrix or array isn’t just a way of storing information during the simulation, but actually is the simulation itself.

Many real-world situations can be simplified as a sequence of objects in a line or an arrangement across a flat space — in other words, they can be faithfully represented by either a list of numbers (a one-dimensional matrix) or a regular grid of cells (a two-dimensional matrix). During the course of the simulation, the objects interact with those near-by according to a set of predefined rules, with the identity of each discrete position on the line or plane changing over time. Such a system is called a cellular automaton model.

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A Living Mars?

GT-coverThe possibility of a living Mars is deeply ingrained in popular culture. The observations of the astronomer Percival Lowell, and his interpretation that these canals were built to channel melt-water from the polar regions down to the dying cities and farms huddled around the equator, are well known. Even into the 1960s, textbooks were being published that explained the temporal variation in surface brightness as due to the seasonal spread of vegetation. Martians are the science-fiction writer’s alien invader of choice, from the heat-ray-wielding tripods of H.G. Wells to the bulbous-headed aggressors of Tim Burton’s 1996 filmMars Attacks. With the armada of robotic probes currently orbiting and roving across the red planet, Mars has never been so fore-front in the public eye. Much of this interest is focussed on the possibility that our planetary neighbour has supported an independent genesis of life, and that in certain regions it may remain habitable even to this day. In this feature article, a selection of some of the most recent results and discoveries concerning the astrobiological potential of Mars will be discussed.

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Life’s a beach on planet Earth

Life-beachDid life on Earth begin on a radioactive beach? That’s the claim of one astrobiologist, who says that life’s ingredients could have emerged from the radioactive sand grains of a primordial beach laced with heavy metals and pounded by powerful tides.

Martian Death Rays

Crusader-1069440117_LOWRESWhen I tell people that I spend my days testing the possibility of life on Mars they usually reply in one of two ways. ‘No seriously, what do you do?’ is only slightly more common than the wittier ‘So you’re not holding out for much fieldwork, then?’ Astrobiology is a bright young discipline, aiming to answer some of the most fascinating questions within science and dinner-table conversation alike. Does life exist ‘out there’ among the pinpricks of light in the heavens, or are we alone in the cosmos? No current scientific field fires people’s fascination more than the quest for extraterrestrial life, and a large proportion of students have cited the reason for continuing science is their interest in astrobiology. For now many astrobiologists’ money is on Mars, our planetary neighbour, as it was once a lot like Earth.

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