Archives for August 2017

But all those scenarios presuppose that aliens are like us. That they have our wants and needs. So let’s do a little dumpster diving of our own to try and suss out what alien life might be like.

Let’s bounce back to 2014 when NASA released a paper on the building blocks of life.

Methane is a carbon atom bound to four hydrogen atoms. On Earth, much of it is produced biologically (flatulent cows are a classic example), but it can also be made inorganically; for example, volcanoes at the bottom of the ocean can release the gas after it is produced by reactions of rocks with seawater.

Ozone and oxygen were previously thought to be stronger biosignatures on their own. Ozone is three atoms of oxygen bound together. On Earth, it is produced when molecular oxygen (two oxygen atoms) and atomic oxygen (a single oxygen atom) combine, after the atomic oxygen is created by other reactions powered by sunlight or lightning. Life is the dominant source of the molecular oxygen on our planet, as the gas is produced by photosynthesis in plants and microscopic, single-cell organisms. Because life dominates the production of oxygen, and oxygen is needed for ozone, both gases were thought to be relatively strong biosignatures. But this study demonstrated that both molecular oxygen and ozone can be made without life when ultraviolet light breaks apart carbon dioxide (a carbon atom bound to two oxygen atoms). Their research suggests this non-biological process could create enough ozone for it to be detectable across space, so the detection of ozone by itself would not be a definitive sign of life.

“However, our research strengthens the argument that methane and oxygen together, or methane and ozone together, are still strong signatures of life,” said Domagal-Goldman. “We tried really, really hard to make false-positive signals for life, and we did find some, but only for oxygen, ozone, or methane by themselves.” Domagal-Goldman and Antígona Segura from the Universidad Nacional Autónoma de México in Mexico City are lead authors of a paper about this research, along with astronomer Victoria Meadows, geologist Mark Claire, and Tyler Robison, an expert on what Earth would look like as an extrasolar planet. The paper appeared in the Astrophysical Journal Sept. 10, and is available online.

Methane and oxygen molecules together are a reliable sign of biological activity because methane doesn’t last long in an atmosphere containing oxygen-bearing molecules. “It’s like college students and pizza,” says Domagal-Goldman. “If you see pizza in a room, and there are also college students in that room, chances are the pizza was freshly delivered, because the students will quickly eat the pizza. The same goes for methane and oxygen. If both are seen together in an atmosphere, the methane was freshly delivered because the oxygen will be part of a network of reactions that will consume the methane. You know the methane is being replenished. The best way to replenish methane in the presence of oxygen is with life. The opposite is true, as well. In order to keep the oxygen around in an atmosphere that has a lot of methane, you have to replenish the oxygen, and the best way to do that is with life.”

Scientists have used computer models to simulate the atmospheric chemistry on planets beyond our solar system (exoplanets) before, and the team used a similar model in its research. However, the researchers also developed a program to automatically compute the calculations thousands of times, so they could see the results with a wider range of atmospheric compositions and star types.

In doing these simulations, the team made sure they balanced the reactions that could put oxygen molecules in the atmosphere with the reactions that might remove them from the atmosphere. For example, oxygen can react with iron on the surface of a planet to make iron oxides; this is what gives most red rocks their color. A similar process has colored the dust on Mars, giving the Red Planet its distinctive hue. Calculating the appearance of a balanced atmosphere is important because this balance would allow the atmosphere to persist for geological time scales. Given that planetary lifetimes are measured in billions of years, it’s unlikely astronomers will happen by chance to be observing a planet during a temporary surge of oxygen or methane lasting just thousands or even millions of years.

Cool. Flatulence and pizza pretty much describes my entire life. Nevertheless you’ll note that a lack of oxygen, the invisible stuff we hork into our lungs along with the nicotine we’re smoking, isn’t a deal breaker.

If you have some time to kill, SPACE.com has a series of articles about how scientists will be searching for alien life and how you can help.

Your help will require a credit card but you’ll know that going in so it’s not clickbait either.

Meanwhile, while everyone is thinking that aliens are a kazillion miles away (that is a number invented by toddlers which is used to describe how much ice cream costs), our old pal Ian O’Neill thinks our galactic neighbors might, just might, be a lot closer than you imagine.

You already saw above how methane (i.e., planetary cow farts) can provide an environment for life to evolve. Well, there’s a moon in our solar system that has that in spades.

Titan.

When studying Titan’s nitrogen-rich atmosphere, ALMA detected three unambiguous millimeter-wavelength signals produced by vinyl cyanide that originated from 200 kilometers above Titan’s surface. It is well known that the moon’s atmosphere is a vast chemical factory; the energy of the sun and particles from space convert simple organic molecules into more complex chemistry. These chemicals then cycle down to Titans rich hydrocarbon surface.

But speculating about life on Titan is a hard task. The moon’s atmosphere is often compared with that of early Earth’s, but there are some huge differences. Titan is crazy-cold, averaging around 95 Kelvin (that’s an incredible -178 degrees Celsius or -288 degrees Fahrenheit); at no time in history has Earth’s atmosphere been that cold. Also, it’s thought that early Earth had large quantities of carbon dioxide in its atmosphere, Titan does not. As for water? Frozen. Oxygen? Forget about it.

So this research underpins our quest to find the chemistry of life as we DON’T know it, using the building blocks that follow the pattern of life that we do know, but swapping out key components (like water) to see if an analog of life’s chemistry can under very alien conditions.

“Saturn’s moon, Enceladus is the place to search for life like us, life that depends on — and exists in — liquid water,” said [Jonathan Lunine (Cornell University)]. “Titan, on the other hand, is the place to go to seek the outer limits of life — can some exotic type of life begin and evolve in a truly alien environment, that of liquid methane?”

Perhaps it’s time for a return mission to Titan’s extreme surface.

You know what, let’s set Titan aside for a second and just start by returning to science. So that our Internet searches return useful information and facts instead of the bullshit I listed above. I’m tired of the “but it could be true” crap that passes for cognitive thought. The sun could be an undulating ball of orange sherbet, thousands of years of science saying contrariwise be damned. If you think it is, by all means, fire yourself in its general direction and bring a spoon. We’ll all learn something useful from your quest.

Mostly that the phrase “The Stupid, It Burns” is literally true in that instance.

Simon Worrall, over at National Geographic, interviewed scientist/comedian Ben Miller about the realistic possibilities concerning alien life and when we could expect to find it.

Now, to get the scientific perspective on extraterrestrials, National Geographic has turned to a comedian, albeit one who pursued a Ph.D. in physics. The host of the British TV show It’s Not Rocket Science, Ben Miller has recently published a book called The Aliens Are Coming! The Extraordinary Science Behind Our Search for Life in the Universe.

Speaking from his home in Gloucestershire, England, Miller explains why the TESS project could finally tell us if there is life elsewhere in the universe, how comedy and science connect, and why we will need a new Rosetta Stone to interpret alien messages.

You write in your book that we are living through one of the most extraordinary revolutions in the history of science—the growing belief that we are not alone.

When I was studying at university, we weren’t even sure if there were planets around other stars or whether the solar system might be a one-off. But for the last few decades we have been on this extraordinary voyage where we’ve found thousands of planets around other stars. Strangely, we started looking for planets a long way out because of the technology we had at the time. Now we are starting to look at the stars closest to our own.

Recently, there was an exciting discovery that the very nearest star to us, a red dwarf, has got a planet called Proxima b. Not only that, but the planet is the right distance from that star to have liquid water on its surface. We think liquid water is very important for life. So, right on our doorstep, the conditions might be right for life.

Just FYI, Proxima B would be a hellscape and not really a good place for life. Think dry, lots of radiation, and not much atmosphere, of any kind.

In other words, not a good vacation destination.

If you’re interested in science at all I strongly recommend you click the link above and read the whole article. It has a Star Trek joke.

Consider that incentive enough.

Anyway, normally scientists are reluctant to put timelines on anything when it comes to supposition, but Mr. Miller makes a bold, and fascinating, exception to that rule.

You know what the last question has to be: Are the aliens really coming?

Within the next ten years we’ll know whether the nearest Earth-like planets to us have got life on them. That has enormous implications for us as a species. Once we find life out there, you have to think that other intelligent life-forms and civilizations exist as well.

At the moment we are in this extraordinary position that our planet may be the only thing in the entire universe with life. So we would be taking a closer step to one of two extraordinary results: that we are the only life-form in the universe or that we are not alone. Either will be species defining. It will change the whole way we view ourselves: religion, politics, our individual psyches, everything.

One of these two possibilities has to be true. It’s just us—or we are not alone.

If we are alone, and I lean against that, what will we do? We have the ability to travel the solar system now and there’s nothing but money and time preventing us from spanning the galaxy. Do we start an empire of our own? Or do we just settle in for the inevitable end?

Flip that for a second, what if we’re not alone? How would we even begin to communicate with them? Unlike on TV these aliens are, in no way, obligated to be closely evolved to us either physically, socially, or technologically. They may use colors for language. They may not need language at all, at least not how we define it.

Or they may just think we’re yummy.