Life on Mars

No, we haven't discovered life on Mars.  Yet.  But hopes are high, as the rover Curiosity and earlier rovers have confirmed the Red Planet does indeed have signs of conditions that would have supported life there at one time.  It may be a matter of time before we discover the proof we're looking for.  Until then we can only speculate.  But instead of speculating if it had life, let's try and look at what kind of life it might have had.

Public Domain image

One of the first things we need to determine is the temperature and climate necessary for life.  It is in what some consider to be the Habitable Zone.  But since Mars is half again further from the sun than Earth, it's a lot colder, and one of the trickier parts of this problem is creating a convincing climate model at any time in its history that produces conditions above freezing.  The temperatures on Mars are estimated by infrared thermal mapper data at between 81 °F and −225 °F.  And while life can exist in conditions below freezing, it does prove problematic, especially if there was no warmer time for them to evolve and adapt to less than optimal conditions.  Being able to support life and being favorable for life are two vastly different things.

We have seen signs which point to the presence of water there in the past.  We've seen clouds in Mars' atmosphere, and seen snow falling.  Finding water-formed minerals including calcium carbonite, hematite, jarosite, and goethite on its surface also points to larger quantities of water at some time in its history.  As water is a basic component of life as we know it, these are big steps toward confirming the presence of life there.

Just the hint of water is hardly an ideal situation for life.  About 70% of Earth is covered with water.  About 226,000 forms of life on Earth live in our lakes, rivers, streams, and oceans.  Life is dependent on water, and far more than just having trace amounts of it around.  So how would Mars have gotten that amount of water?

Size of Tharsis Volcanoes, by the Lunar and Planetary Institute

Some scientists theorize that the Tharsis Montes, a volcanic bulge containing the largest volcanoes in the solar system, is large enough to have caused changes to the climate of the entire planet.  Since these volcanoes are so huge - the tallest has a whopping summit elevation of 59,000 feet - they could have spewed enough water vapor and carbon dioxide to create a much thicker and warmer atmosphere in a series of eruptions.  Some estimate the amount of gasses released into the atmosphere could have given Mars a thicker atmosphere than Earth's.  And because of the size of this bulge, it's theorized it has affected the spin axis and changed geographic locations of the planet's poles.  Based on the picture above, it's not hard to understand why.

The Mars of today and the Mars of eons ago could look drastically different.  What is now frozen desert wastelands could have once been fertile plains and forests, and the cradle of life such as we have never seen on Earth.  Would life on Mars have been that dissimilar to Earth's?  We can probably assume the evolution of carbon-based life forms, but from there all bets are off.

Throughout Earth's history, the predominant phylum has changed several times.  Fossil records indicate mammals weren't always the top dog.  At one point plants, fish, amphibians, and dinosaurs were all top forms of life here.  At one point, so were arthropods.

What if a similar phylum to Earth's arthropoda became dominant?  We know from experience they can be very successful, and it's not hard to imagine a Martian landscape covered in giant bugs.  Spiders, ants, scorpions, and the like are quite successful in arid lands and severe climates, and cockroaches live goddamn anywhere they want.  It wouldn't be the first time someone envisioned bugs living on Mars.

Camel Spider © by Scott

Life on Mars could also be on a much different scale than Earth's.  While larger life is more impressive and makes for better stories, my bet would be on smaller life.  It's easier to imagine them surviving on less water and in more hazardous climates.  Larger animals require so much more to be right in their environments, from food sources to temperatures to available space, that it's hard to see them surviving on a planet more hostile and extreme than our own.  But given enough time, and assuming you believe in the theories of evolution, it's not hard to visualize a society of intelligent arthropods, at a fraction of our own size, living comfortably in the lands of ancient Mars.

One would, however, assume a completely different evolutionary chain to have happened in the event of life on Mars.  Even a small change in environment can produce drastically different results.  It's not hard to see where life on Mars would have taken a very different turn from that on Earth.

Mars and Earth are more alike than we might think.  While many find it easy to picture something quite alien and different from life here, the reality is that Mars is not that dissimilar to Earth.  The image below compares an outcrop of rocks on Earth with a similar outcrop on Mars.  Can you tell which is which?  You can visit NASA's Mars Exploration Program website to find out.  You got it wrong, didn't you?

Rock Outcrops on Mars and Earth, by NASA

Certain functions and structures are the easiest and simplest ways of doing things, and that's critical to evolution.  Many different types of animals all have the same basic components, primarily because that's the best way to do things.  Plants all function in basically the same way.  And they most likely will on Mars too, because the basic foundation for life - the chemicals and elements that make up the structure of Mars - is the same as that of Earth.

So it would be no surprise to find life there.  It may be a matter of time and effort.  Chances are, if we do discover life, it won't be little green men, but rather little green microbes.  It won't be nearly as exciting from a layman's point of view, but for science it will be a discovery of monumental proportions.  One thing is for sure: Ray Bradbury would have been excited beyond belief to know there really was once life on Mars.

Mission To Mars!

As you've probably heard by now, NASA's newest six-wheeled rover Curiosity landed on Mars this month.  No small feat.  There were so many things that could have gone wrong, and didn't.  Instead of disappointment at what might have been, we have an awesome robotic machine tearing up the Red Planet's soil, taking samples, pictures, and data of all sorts.  Outstanding!

Curiosity was launched from Earth on the Atlas V Evolved Expendable Launch Vehicle on November 26, 2011.  It landed in the Gale Crater on Mars on August 6, 2012, after traveling 354 million miles to get there.  Not only did it make it there, it landed within a mile and a half of its target landing spot, which is a damn fine bit of accuracy for something that far away.  Curiosity is scheduled to explore the planet for at least 687 Earth days, or one Martian year, and cover a distance of 3.1 by 12 mi miles.  It's nuclear powered, and has the fuel to function for about four Earth years, so we may see more of it than just what's planned.

Atlas V Evolved Expendable Launch Vehicle © by Official US Air Force

I've put together some links and resources to follow Curiosity's mission there.  NASA (Twitter handle @NASA) is the ultimate source of all things Curiosity, but not the only one.  The NASA Jet Propulsion Lab (Twitter handle @NASAJPL) manages most of the robotic missions exploring Earth, the solar system and the universe, including this one to Mars.  Curiosity itself shares a lot of information, with the Twitter handle @MarsCuriosity, on Facebook, and on Google +.  Of course, it's not live tweeting and posting from Mars, but don't tell it that.

It has already sent back some amazing footage, including the hair-raising decent onto the surface of Mars, and the first 360 degree panoramic shot of the surface.  Even more amazing is seeing ourselves from the perspective of another planet.

Earth From Mars © NASA Goddard Space Flight Center

NASA named Curiosity's landing site on Mars for the late science fiction author Ray Bradbury, calling it the Bradbury Landing Site.  If only he could have seen it happen.  Bradbury was hugely instrumental in sparking and nurturing our interest in the Red Planet.  I think he would have loved to see these wonderful pictures sent back from the planet he wrote so much about.

Wall of Gale Crater © NASA/JPL-Caltech/MSSS

So what's in store for Curiosity in the future?  Well, besides the beautiful pictures of the Martian landscape and the view from there into our galaxy, we can expect quite a bit more.  Its mission is to explore the planet's "habitability," to determine if it ever had an environment that could sustain life.  Most of this research will be conducted with soil analysis, studying rocks, soils, and Martian geology to understand chemical composition and forms of carbon there.  This will help assess what the environment was like there in the past, and could lead to the discovery of life there.  At the very least, it should tell us if life on Mars was ever even a possibility.

Wall of Gale Crater © NASA/JPL-Caltech/MSSS

In addition to exploring the geological and mineralogical composition of the surface and near-surface, it will study and catalog the organic carbon compounds and chemical building blocks of life (carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur) on Mars, giving us an understanding of the biological processes that have happened there.  It will also study the atmospheric evolution processes from the present state and distribution of any water and carbon dioxide it finds there.  This will go a long ways toward determining if there was ever life on Mars.

Wiggle in the Gravel © NASA/JPL-Caltech

Curiosity is much larger than the previous rovers we've sent there.  It also has over ten times the mass of scientific instruments they had, so its capacity for learning and discovery are far greater than ever before.  It has more missions than they did, and more capacity to send its findings back to its home planet.  Until the next mission is launched in 2016, it's our best shot at discovering life on Mars.

So is there life there?  Was there ever?  Were the conditions ever right for it?  Some folks think so.  In fact, some think life on Earth actually originated from Mars.  With Curiosity, we may soon find out the answers to those questions and many more.

Update:  Found a wonderful film/animation of how Spirit and Opportunity got to Mars.  Well worth a view, preferably full-screen.

An Egg from Space, or Something More Earthly?

Alien Egg, © Jonathan Dalar

There it is, folks.  In all its raw glory.  But what the hell is it?

I found it in my youth, circa 1980-1982.  It was lying on the surface of the ground in the middle of a wheat field in the heart of Eastern Washington's Palouse country.  It hadn't been unearthed.  It had no signs of being previously buried.  It was just sitting there on top of the dirt, so I took it home to find out what it was.

Wheat Fields in the Palouse, © Nikky Stephen

It's more or less egg-shaped, and consistent in material all around.  At five and a half inches long at its longest dimension, it tips the scales at somewhere over nine pounds.  The more interesting part is it's at least partially iron.  I'm guessing it's between 10% and 30% ferrous, which appears to vary some, depending on where you measure it.  It responds slightly to magnets, more so in certain areas of the surface than others.

Alien Egg, © Jonathan Dalar

I've dragged it around with me over the years, and have had a few interesting conversations over it.  A few folks thought it was a thunder egg, or geode.  At least initially.  They do until I point out the surface looks nothing like any geodes I've ever seen, and it does not feel hollow in the least.  It's too heavy.  It feels more like iron than a hollow stone.  One does not get the impression there are crystals on the inside, should it be cracked open.

Thunder Egg, © Joel Davis-Aldridge

The other thing often mentioned is a meteorite.  In spite of their relative rarity, it's easier to believe than a geode.  It's at least partially ferrous, which is a trait it holds in common with meteorites.  I haven't measured the exact percentage of iron it has, but the 10% to 30% common in meteorites isn't too far off.  You can feel the definite pull toward a magnet when you hold one to it, but it's weak enough they don't cling.

Meteorite, © Amgueddfa Cymru - National Museum Wales

It does not have any indication of rust, however, which is a trait commonly found in meteors.  After years of storage in various garages and back storage rooms, it would have certainly rusted by now if it's ever going to. In spite of the iron content it has, I doubt it ever will.

Holsinger Meteorite, © Samuel Hansen

It also does not have any true indication of pitting or thumbprints, also common in meteorites.  The surface is rough, and covered with small, shiny crystal faces.  They're flat and smooth, similar to those found with pyrite, or fool's gold.

Alien Egg, © Jonathan Dalar

It does, however share color and overall appearance with some types of meteorites, which makes the discussion a little more interesting.  The shape is also interesting.  While round rocks are not uncommon in nature, most have been shaped by water.  There is no evidence of such exposure to water with this rock.  It would be nice to find that it came from beyond our world.

2009 Leonid Meteor © Ed Sweeney

I'm still not sure what it is, and I'm not completely sold on any of the theories I've come up with over the years I've had it.  It's intriguing, if only for its feel and appearance.  It's probably just my overactive imagination, hard at work as usual, but there seems to be more to it than just a rock.  I'd like to think it's an alien egg, and that someday some sort of strange creature will emerge from it.  I'd like to think it's a chunk of some rare and distant metallic planet that somehow found its way to the fields behind my childhood backyard.  Maybe even from the same place as previous visitors to earth came from.

Easter Island © Stéphane Guisard

I haven't found out for sure what it is, primarily because of these fantasies.  Not knowing exactly what it is, however mundane that might be, keeps those wild and fanciful theories in the mix, even when I know they're not serious possibilities.

Someday my son and I will take it down to the University of Washington geology department, and see if we can't get someone there to take a look at it.  Someday we'll have a definitive answer.  We'll know exactly what it is and where it came from.  With that we'll rule out aliens, and probably even junk from outer space.  Until then, it's fun to think about the possibilities.