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Scientists May Have Discovered an Alien Megastructure…No Seriously.

Scientists believe they may have spotted an Alien Megastructure orbiting a sun in a distant solar system. Not even kidding. There is a massive object orbiting a distant star and a planet or asteroid have already been ruled out as possible explanations. Relax, no one looked into a telescope and spotted the Death Star, but from the sounds of it, this object may be just as massive. Read on as Melissa, our science guru, breaks down the facts.

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Warning: It’s about to get real sciencey up in here. Yeah, Aliens are cool, but you’re going to have to learn a bit about the science we use to find them.

What is Kepler?

The Kepler Space Observatory is a spacecraft launched by NASA in 2009. It provides an opportunity to explore the galaxy for habitable planets.  It does this by observing a fixed location and watching the stars’ brightness.  In time, planets will sometimes orbit those stars, causing a slight dip in the brightness of the observable light.  That dip can be calculated to a certain percentage, and then, based on the size of the star, the size of the planet can be determined.  This is known as transit photometry.

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Alien Megastructures, you say?

Recently, a very large dip was discovered on a star named KIC 8462852.  This star is 1500 light years away from earth. Whereas a planet will cause a dip in the light by a percentage or two, this star had a dip of about twenty percent. Twenty percent of the light emitted from this star was blocked by something incredibly large. It would have to be about half the size of the star itself to block twenty percent of the light output. Comparatively, Jupiter, the largest planet in our solar system, is only one tenth the diameter of our sun. This star is estimated to be 1.5 times larger than the size of our sun, making it nearly impossible for the object to be a planet. Many theories have been explored and there are some very likely natural causes for the dip, yet this mystery has lead some experts to consider this to be the result of a giant alien megastructure, periodically dimming the light with its orbit.

Jason Wright, an astronomer from Penn State University, has been investigating what a huge alien construction in space might look like from Earth. He told The Atlantic: “Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilization to build.”

Where is the Infrared?

Tabetha Boyajian, Yale University, led the investigations into the mysterious signals and found that the most likely natural cause was the break-up of a comet around the star. As the icy remains expand into giant clouds they could temporarily block out the light, causing the observed signal. But this should cause dust to scatter around the star, producing an excess of infrared radiation that should be easily detected from Earth. As yet, no such signal has been found. One of the main arguments against this alien megastructure theory, is that something as large as this object would be absorbing a lot of heat from the star.  That heat energy would then be re-radiated and observed as Infra-Red wavelengths, and as of now no IR light has been observed from this star.  This lack of Infrared is making it difficult to find the most likely explanation for the dimming event.

Transit Photometry

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Despite the disadvantages of this type of method for discovering exoplanets, the main advantage of the transit method is that the size of the planet can be determined from the lightcurve. When combined with the radial-velocity method (which determines the planet’s mass) one can determine the density of the planet, and learn something about the planet’s physical structure. The transit method also makes it possible to study the atmosphere of the transiting planet. When the planet transits the star, light from the star passes through the upper atmosphere of the planet. By studying the high-resolution stellar spectrum carefully, one can detect elements present in the planet’s atmosphere.

The Plot Thickens

Since the original news hit about the strange observations made about the star KIC 8462852, from the Kepler Space Observatory, astronomers have been busy looking over data and have uncovered some new information.  Bradley Schaefer, an astronomer at Louisiana State University, wanted to investigate this particular star’s dimming pattern further. He went to Harvard to look at old photographic plates of stars. There were more than 1200 photographs of KIC 8462852 to view as part of a survey collected between the years 1890 and 1989. What he found made the mysterious star even more puzzling. He confirmed that the star is flickering on short timescales, similar to the findings of the Kepler Space Observatory, but the Harvard collection also revealed that its been doing this over the course of a century.

What does this mean for the initial hypothesis?  Could the break-up of comets, orbiting around the star be the answer? Schaefer calculated that it would take 648,000 stars, each 200 km wide to have passed by the star, which he was was “completely implausible.” (New Scientist)

The results also changed the requirements for the alien megastructure hypothesis. Schaefer is unconvinced that an Alien civilization would be able to build something capable of covering a fifth of a star that massive in just a century. He also reiterated the lack of infrared signal that would be required for such a structure.  

Schafer added in his report that a century-long dimming like the one from the star, is completely unprecedented for any star of its size. He adds, the “century-long dimming and the day-long dips are both just extreme ends of a spectrum of timescales for unique dimming events, so by Ockham’s Razor, all this is produced by one physical mechanism.  This mechanism…must be some ongoing process with continuous effects.”  (Cornell)

Ockham’s Razor is a problem solving principle with philosophical origins.  It basically states that the simplest explanation for something is usually the right one.  Well, nothing stands out as the obvious reason for this phenomenon yet, other than the confirmation that it’s the same thing that’s caused it for over a century.  Pretty awesome even if it’s still a mystery.

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Star Wars: The Science of Star Killing

In Star Wars The Force Awakens, the galaxy is going to face a new threat, The First Order. This new evil empire has a super weapon capable of destroying whole solar systems, which they keep at their base of operations: Starkiller Base.

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If the name “Starkiller” sounds familiar, its probably because an early draft of the first Star Wars script called the main character “Luke Starkiller” instead of “Skywalker”, and a lot of Star Wars
writers like to reference that fact with easter eggs throughout the Star Wars universe.

It seems though that the First Order are using the name literally and that their new weapon may actually be able to destroy stars. Leaving aside for now the question of what this could mean for the Galaxy and our heroes, let’s first ask the question: how would that even work? Watch the video below to see how we break down the galactic science behind star killing.

The gravity that holds the star together is delicate. If the amount of stuff in the star doesn’t stay dense enough the explosions at its core will start to expand out in a massive explosion called a Supernova. So, if you want to make a star go supernova, you just have to add enough energy to make its mass outweigh its density.

But say you actually do want to use a laser, just for old times’ sake. Well, one way to do that is the use the technique of laser cooling. Laser cooling is a method scientists actually use when researching microscopic particles. It works because temperature is largely caused by the atoms inside of something moving at a faster rate. If you can tune
a laser finely enough to push individual atoms, you can slow down their rate of movement and cool off the structure their part of. How does this help with our star problem? Well simple, the exploding stuff acts like a core reactor. But, if you reduce the temperature of the core, you’ll also decrease its amount of fusion.

The star’s balance of gravity and expansion will be thrown off and it will collapse in on itself, and boom goes the dynamite.

The video dives deeper into the science, but basically that is the scientific method for star killing. Remember kids, don’t try this at home.

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Breakthrough Starshot: Exploring the Infinite Abyss



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Stephen Hawking is a cosmologist, professor, theoretical physicist and one of the greatest living scientific legends.  He, along with Yuri Milner, an entrepreneur, venture capitalist, and physicist, as well as Mark Zuckerberg of Facebook fame, announced the Breakthrough Starshot initiative in April of 2016.

According to the website, Breakthrough Starshot is a “$100 million research and engineering program aiming to demonstrate proof of concept for a new technology, enabling ultra-light unmanned space flight at 20% of the speed of light; and to lay the foundations for a flyby mission to Alpha Centauri within a generation.”

Let’s break this down to understand what manner of science fiction we’re dealing with here.

 

Alpha Centauri

Alpha Centauri is our neighboring star system that is located four light years away. With current rocket propulsion technology – our current abilities to drive or push a rocket forward – it would take hundreds of millennia to reach it.

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The Speed of Light

In the past fifteen years, fast technological advances have opened up the possibility of light-powered space travel at a significant fraction of light speed.  The speed of light is 671 million miles per hour. According to the statement from Breakthrough Starshot, the program would push miniature space probes to speeds up to 100 million miles per hour, roughly 20% the speed of light.

The program would include a light beamer – basically a number of high powered lasers – located on earth, that would push nanocrafts to their top speeds.

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Nanocrafts you say?

These are gram-scale robotic spacecrafts comprising two main parts:  

  • A “StarChip”, which is a wafer sized component carrying cameras, photon thrusters, power supply, navigation and communication equipment, and constituting a fully functional space probe.
  • The “LightSail” is a meter-scale sail that is no more than a few hundred atoms thick and at gram-scale mass.

So, you could picture little wafer sized components surrounded by what look like sails, that lasers from earth push to speeds of 100 million miles per hour.  Crazy, right?

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Moore’s Law

The scientists explain that a few technological advances are making this invention possible.  First is the idea of Moore’s Law, which is the observation made by Gordon E. Moore in 1975, that explains that the number of transistors in dense integrated circuits will double approximately every two years. Basically, technology will only get smaller.  We’ve seen evidence of this over the decades and this observation has proved true every two years up to about 2013.  Its still a viable prediction for scientists to work with, but the rate at at which technology is advancing is indeed slowing down. Not dramatically, but it may perhaps change to every 3 or 4 years that we see a shift in scale of technological advances.  

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Nanotechnology

The second advancement in technology that is making nanocrafts a possibility are the advances in nanotechnology. Nanotechnology is science, engineering, and technology conducted at the nano-scale, which is about 1 to 100 nano-meters. Nano-science and nanotechnology are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering. These advances are becoming more and more a reality.

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Interstellar Space

Once the nanocrafts reach Alpha Centauri in a few decades, they would then beam home images of possible planets and analysis of magnetic fields. Along its journey, the nanocrafts could supply worlds of information about asteroids it crosses and solar system exploration. While Breakthrough Starshot is not the first project to explore the idea of interstellar space travel, it far outweighs any previous attempt in terms of funding. In 2011 the US research agency DARPA and NASA provided $500,000 to seed the “100 Year Starship Project”. That doesn’t quite compare with the $10 million that has been allocated to Breakthrough Starshot.

 

Path to the stars

The research and engineering phase is expected to last a number of years. Following that, development of the ultimate mission to Alpha Centauri would require a budget comparable to the largest current scientific experiments. Once it is assembled and the technology matures, the cost of each launch is projected to fall to a few hundred thousand dollars.

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I’m in, so when do we get the popcorn ready?

One of the great things about this initiative, aside from actually reaching interstellar space with a camera ready to send images to earth, is how the very development of this program is inviting the public to chime in with opinions and suggestions.  The team is essentially crowd-sourcing solutions to the number of engineering and logistical challenges that remain before this is a reality.  Transparency is important to the Breakthrough Starshot team, which is a great move, in my opinion. In about 25 years, we can finally microwave that popcorn as we await images of possible earth like planets from Alpha Centauri.