Is it Aliens? What’s the deal with this new star?

Astronomy can occasionally be like high school. New discoveries spark curiosity and debate that sometimes can get ahead of itself, especially when the media gets involved. This past week has been the perfect example. In case you haven’t heard, the story goes like this: Scientists have found a new star and it’s weird. So weird in fact that one of the few explanations they are still considering to explain what is going on is that there might be an alien megastructure built around it.

Before we get too far into this, I want to point out that I am using the word “new” as in “we are now pay attention to this star.” It has always been in existence, minding its own business, 1500 light years from Earth. The star is named KIC 8462852, but for the sake of simplicity and a decent metaphor let’s call it Clint.

Clint is the kid who shows up for the first day of grade 12 and immediately catches everyone’s eye. He doesn’t dress like anyone else, doesn’t follow the same rules as everyone else, and doesn’t care that you can’t figure him out. He is mysterious, but you don’t know if he’s cool or just disturbed. Clint might even be a dork who goes home and plays with slide rulers all night, we just don’t know.

In real terms, the star we’re calling Clint is interesting because of what is going on around it. As you might recall from our discussion of exoplanets, astronomers detect planets outside our solar system by watching the light from distant stars. When a planet passes in front of a star, the light dims slightly. From this dimming, smart folks can work out the size, composition, location, and sometimes colour of the planet in question.

The problem with Clint, is that the dimming we’re seeing just doesn’t make sense. The thing with planets, is that they are generally pretty insignificant compared to their stars. As we learned in Sketchy Fact #100, over a million Earths could fit inside the Sun. The upshot is that even massive planets like Jupiter only block about 1% of their star’s light when they pass in front of it. However, scientists watching Clint have seen drops by as much as 22%! To understand how crazy that is, imagine being at the beach when a cloud moves in front of the sun and blocks a quarter of its light. The difference it makes is enough to make you want to layer up.

The other thing about the dimming of Clint (dibs on that album name) is that it is unpredictable. Planets orbit their stars at regular intervals. If you were watching the Earth pass in front of the Sun, you could reliably say that there will be a 365 day gap between so-called “transits.” Clint on the other hand is being blocked seemingly at random, and really frequently. Scientists have observed hundreds of dips in the light we’re receiving that indicate objects of all shapes and sizes. So what is going on?

Well, we are pretty sure we know what it isn’t. It’s not a problem with the Keplar space telescope that has been collecting the data and it’s not due to starspots (natural formation on the surface of a star that impact the light it gives off. It also probably isn’t a dust cloud caused by a collision between objects orbiting the star. Dust clouds of that sort gather and radiate infrared light, and that isn’t happening with Clint. So what is left?

There are two main theories astronomers are working with at this point:

1        Theory 1: It could be comets. It turns out there is another star that is relatively close to Clint. This star’s gravity could be disturbing Clint’s Oort cloud (most stars have a cloud of icy objects like comets in the far reaches of their solar systems.). If the neighbouring star passes close enough it could cause comets to fall into the inner solar system. As these comets melt they would release dust and occasionally explode, explaining the unpredictable nature of the dimming. In this case, it would be weird not to see excess infrared light, but not completely ridiculous since comets are made up of a lot more than just dust.

2       

      Theory 2: It might, slightly, possibly, potentially could be aliens. I know, I know. Most people are either going to laugh that off or accuse me of getting their hopes up. But the pattern of dimming the researchers are seeing is what you would expect if an alien civilization built a megastructure like an array of solar panels around their star to generate clean, reliable energy.

The next few months will tell us more as scientists use the massive radio telescopes we have on Earth to try and detect radio signals coming from Clint’s system. They are expecting more data as early as January.

In the meantime, we’ll just have to sit in science class with pondersome looks on our faces as we try to figure out if we should give Clint a wedgie or ask him to prom.

How to Find an Alien Race

To my mind, one of the coolest things that a basic understanding of science allows you to do is stare up at the night sky and imagine that somewhere in that mess of twinkling dots is another life form doing exactly the same thing. However, even mentioning the idea of aliens is enough to make a portion of people snicker and roll their eyes, but when you consider the probabilities at work in the universe the odds are on the side of believers.

One of the key pieces of the argument for the existence of aliens has long been the fabled Drake Equation created by astronomer Francis Drake in 1961 to help encourage investment in SETI (the Search for Extra Terrestrial Intelligence). The drake equation basically takes the huge number of planets and stars that we think exist and whittles it down to a conservative estimate of the number of alien civilizations. It takes into account six variables: the rate of star formation in the galaxy you are looking at, the fraction of stars that form planets, the number of planets that could support life, the probability that life actually emerges on one of these planets, the probability that intelligent life evolves, the probability that one of these civilizations develops a way to communicate with us and finally the length of time that a civilization like that is likely to exist.

Basically it is a lot of multiplying down that gives an estimate that there are around 12,000 civilizations capable of communication that should exist in our galaxy alone. So how can we find them?

The answer might lie in a combination of the laws of thermodynamics and something called the Kardashev Scale. The latter describes three types of civilizations that can exist at advancing levels of awesomeness. Civilizations are defined by the amount of energy they use and include:

• Type I – Similar to Earth now. Some people have argued that Type I civilizations should be able to make use of all the energy produced by its planet (geothermal, wind, tidal energy, etc.). Based on that definition, humans have a Type 0.7 civilization, possibly reaching 1.0 in the next few centuries. 

• Type II – Civilizations that can use all the energy produced by the star(s) at the heart of their solar system.

• Type III – Civilizations that can use all the energy produced by their galaxy.

While it may be fun to imagine what life would be like at each level, all we really need to focus on right now is that each level uses an insane amount of energy compared to the level before it. The thing about energy is that is produces heat, and heat is something that we can see from very far away.

With that in mind, a group of scientists recently set out the find advanced societies across a section of the universe. Researchers at Penn State recently surveyed 100,000 galaxies using NASA's Wide-Field Infrared Survey Explorer (WISE) – a very fancy telescope. They looked at the heat signature from each galaxy and compared it to what you would expect if only natural processes were at work. The idea was that if a galaxy is hotter than you expect it to be, it might be because a civilization there is consuming a lot of energy. What they found was kind of scary…

Out of 100,000 galaxies, 50 where in the “hotter than expected” group. That is a very, very low number. Low enough that when they look at those 50 more closely, they could quickly become zero. If each of those galaxies is supposed to have 10,000ish advanced civilizations according to the Drake Equation, why are things so chilly? Either we aren’t looking at things in the right way or there might not be as much company out there as we thought. Maybe it’s just me, but that is a lonely thought.

Fortunately, it is fairly easy to join the “we don’t know what we’re doing” camp. Astronomers at Berkley are already hard at work looking for other signs of intelligent life and many people remain optimistic that we’ll find something… eventually. The other important thing to remember is that there could be life out there, it just might not be advanced enough to turn up the heat on its entire galaxy yet. It is even possible (although extremely unlikely) that humans have the most advanced civilization for light years around. We might eventually become the interstellar bullies we’ve made so many movies about.  

The Trouble with Tardigrades: The Trials and Tribulations of Nature’s Toughest Animal

Imagine for a moment that you are a hitman for mother nature. It is your job to find and kill any animal she requests. Obviously some contracts are going to be easier than others. Taking the life of a grizzly bear or a great white is going to be a bit more challenging than ending a lamb or grasshopper. However, even sharks and grizzly bears are easy targets compared to nature’s toughest creature. Freeze a shark solid in a block of ice and boil a grizzly bear and your job is pretty well taken care of, but do the same to a tradigrade and you’re in for a long and frustrating wait.

You may not have ever heard of tardigrades, but they are everywhere you have ever been. There are billions and billions of them in every environment on earth. In fact there is a stout branch on the tree of life that contains nothing but the 1000+ species of these little guys. A tardigrade isn’t a bacteria or any other kind of those not-quite animals you hear about being everywhere either, they are honest to goodness animals that you can see with the naked eye… in the right light.

Tardigrades, also known as water bears for their resemblance to very tiny pandas, are on average about 1 millimeter long. That is about the size of the period at the end of this sentence. They are mostly transparent and have eight stubby legs, each ending in an alien/bear/eagle like claw. They spend their days sucking water off of moss and feasting on algae with their spear-like mouths. However, unlike most animals that live in the land of the very small, tardigrades are actually kind of cute in a monstrous sort of way.

They get their name from the Italian word tardigrada meaning “slow walker” because unlike most tiny animals that dart around like Carrot Top on PCP, tardigrades lumber around slowly and pretty clumsily, doing their tardigrade thing. Tardigrades are a scientists best friend because they are small and breed quickly. An individual contains about 1000 cells and has a lifespan of around one year… Unless of course you subject them to the cruelest kinds of punishment imaginable, then they will live WAY longer.

Indeed, a tarigrade is a very peculiar thing. Leave it alone and it will lead a pretty uninteresting life, but if you freeze them, dry them out, cook them, or expose them to radiation you had better be prepared to have your mind blown. Tardigrades can withstand temperatures from 1 Kelvin (-458 F/-272 C) to 148 C (300 F). They can survive pressures 6 times greater than the deepest point of the ocean and brush off a dose of radiation 1000 times greater than what would kill an elephant.

When a tardigrade is thrown into one of these woefully undesireable situations it pulls off an amazing trick. It can dehydrate it’s body by 97%, converting water into a sugar called trehalose which prevents cells from rupturing when they freeze or heat up. When they do this, tardigrades go into a sort of hibernation, almost entirely shutting down their metabolisms. When conditions improve, they simply rehydrate and go back to the business of moss sucking. A tardigrade can survive in its hibernating state for at least ten years but possibly for more than a century.

As if all of this wasn’t enough to bestow them with the honour of nature’s most indestructible creature, tardigrades are the only animals we know of that have survived the vacuum of space. In 2007 NASA sent a team of tardigrades along with a few astronauts up into orbit. They opened the airlock and set the tardigrades floating in space for ten days where they were exposed to extreme cold, extreme heat, and intense radiation. Apparently the tardigrades just treated this as a vacation because when they were brought back to earth they woke themselves up from an extended nap and just went on living. A few even reproduced.

This is all pretty amazing but why does it matter? We can get jealous of tardigrades until the cows come home but it doesn’t help us much, does it? Actually, tardigrades provide good evidence for a long held idea in science called panspermia which is meant to explain where life on earth came from. It is thought that life may have started elsewhere in the universe and been spread by collisions with meteors. When a meteor hits a planet it sends pieces of that planet rocketing into space and drifting through the void. If creatures like tardigrades are tough enough to survive such a trip and land on another planet, life might be a pretty common feature of the universe. Tardigrades themselves might even be an alien life form.

That is real gift that tardigrades give us. Through their survival of nearly everything, including all 5 mass extinction events so far on earth, through their uncountable numbers on earth, and through their ability to travel in space tardigrades provide strong evidence that we aren’t alone in the universe… And if you’re reading this in a mossy forest alcove you’re really not alone.

References:

http://tvblogs.nationalgeographic.com/2014/03/19/5-reasons-why-the-tardigrade-is-natures-toughest-animal/

http://www.wired.com/2014/03/absurd-creature-week-water-bear/

http://www.americanscientist.org/issues/feature/tardigrades/5

https://www.youtube.com/watch?v=6H0E77TdYnY

http://www.todayifoundout.com/index.php/2013/05/the-amazing-tardigrade-the-toughest-known-creature-on-earth-and-beyond/