Space Dust, Not an Alien Megastructure, Is to Blame for Star's Bizarre Behavior


Space is filled with unsolved mysteries, but rarely do they rivet astronomers and sci-fi fans the way KIC 8462852 has. In 2015, researchers announced that the distant star's light had periodically waned over the course of several years (once by as much as 22 percent), prompting some to theorize that a type of power-harnessing "alien megastructure" could be the culprit. This explanation was largely dismissed, but scientists still didn't know what caused the star's bizarre behavior. Now, reports that space dust is likely responsible for the mysterious phenomenon.

Published in the journal The Astrophysical Journal Letters [PDF], a new study of KIC 8462852's behavior "shows that different colors of light are being blocked at different intensities," said Tabetha Boyajian, an astronomer at Louisiana State University and the study's lead author, in a statement. "Therefore, whatever is passing between us and the star is not opaque, as would be expected from a planet or alien megastructure."

KIC 8462852 sits 1500 light-years away from Earth, and is about 50 percent larger and 1000 degrees hotter than the Sun, according to scientists. It's nicknamed "Tabby's star" after Boyajian, who first observed its unusual flickering pattern in 2011 while perusing data from NASA's Kepler Space Telescope with a team of citizen scientists from the online Planet Hunters group. Boyajian and several of the group's members published a paper in 2015 that detailed KIC 8462852's waning and waxing brightness over the course of four years. The data puzzled scientists around the world.

KIC 8462852's otherwise consistent flux was interrupted by sporadic—and substantial—dips in light. Planets can cross in front of distant stars and occlude their light, but even transiting Jupiter-sized planets typically cause a dip of less than 1 percent. In KIC 8462852's case, the difference was up to 22 percent. Further adding to scientists' confusion, KIC 8462852 is an older star that isn't surrounded by the dust and debris from its formation, which can obscure a star's shine.

Theories for the star's behavior ranged from telescope malfunctions to comet fragments moving in an elliptical orbit around the star. Another hypothesis was that a dusty debris disk could be enveloping a black hole located between KIC 8462852 and Earth, National Geographic reports.

Meanwhile, Penn State astronomer Jason Wright hypothesized that alien megastructures, otherwise known as Dyson Spheres, could be harvesting energy from KIC 8462852. (This idea was swiftly debunked.)

To find some answers, Boyajian and colleagues performed follow-up research from March 2016 to December 2017 that was funded through a Kickstarter campaign that raised more than $100,000. Using ground telescopes provided by Las Cumbres Observatory in Goleta, California (and numerous volunteer telescopes around the world), they noted four additional instances in which KIC 8462852 dimmed for stretches of time ranging from days to weeks, according to Gizmodo. (Kickstarter supporters even got to name these instances.)

So far, real-time data from this new study suggests that space dust (perhaps the fragments of a recently destroyed planet or moon) is the likely answer for KIC 8462852's unusual flickering. But no conclusive results have been reached quite yet. For now, the star will continue to stymie scientists. At least they can finally eliminate the phrase "alien megastructure" from their vocabularies.


ESA/Herschel/SPIRE; M. W. L. Smith et al 2017
Look Closely—Every Point of Light in This Image Is a Galaxy
ESA/Herschel/SPIRE; M. W. L. Smith et al 2017
ESA/Herschel/SPIRE; M. W. L. Smith et al 2017

Even if you stare closely at this seemingly grainy image, you might not be able to tell there’s anything to it besides visual noise. But it's not static—it's a sliver of the distant universe, and every little pinprick of light is a galaxy.

As Gizmodo reports, the image was produced by the European Space Agency’s Herschel Space Observatory, a space-based infrared telescope that was launched into orbit in 2009 and was decommissioned in 2013. Created by Herschel’s Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS), it looks out from our galaxy toward the North Galactic Pole, a point that lies perpendicular to the Milky Way's spiral near the constellation Coma Berenices.

A close-up of a view of distant galaxies taken by the Herschel Space Observatory
ESA/Herschel/SPIRE; M. W. L. Smith et al 2017

Each point of light comes from the heat of dust grains between different stars in a galaxy. These areas of dust gave off this radiation billions of years before reaching Herschel. Around 1000 of those pins of light belong to galaxies in the Coma Cluster (named for Coma Berenices), one of the densest clusters of galaxies in the known universe.

The longer you look at it, the smaller you’ll feel.

[h/t Gizmodo]

Why Do Astronauts Use Space Pens Instead of Pencils?

by Alex Carter

It's often said that NASA spent millions of dollars developing a pen that could write in zero gravity, while the Russians just used pencils. It was a warning about looking for a high-tech solution to a mundane problem, of American excess vs. Russian sensibility.

It's also entirely false.

To understand why NASA was so keen on a workable space pen, you have to understand that the pencil is not suited for space travel. The problem is that they have a habit of breaking, shattering, and leaving graphite dust behind. The wood, too, can make it a serious fire risk in the pressurized, oxygen-rich capsule. All of these common issues become life-threatening hazards in space.

Still, there were attempts to bring pencils into space. In 1965, the agency famously ordered 34 specially designed mechanical pencils in hopes of finding the perfect writing tool for astronauts. But at $128 each, they weren't exactly cheap, and it only got worse when the public got wind of the price. Thankfully, an alternative was not too far behind.

Astronaut Walt Cunningham, pilot of the Apollo 7 mission, uses the Fisher Space Pen while in flight.
Astronaut Walt Cunningham, pilot of the Apollo 7 mission, uses the Fisher Space Pen while in flight.

The Space Pen was invented by Paul Fisher, head of Fisher Pen Company. Unlike a typical pen, the Fisher Space Pen uses compressed nitrogen to force ink out of the nozzle, instead of using gravity to make it flow. This made it the ideal device for writing in space, while upside down, or submerged underwater. It wrote crisp and clean, without the safety concerns of a pencil.

Fisher contacted NASA to give his pens a try in 1965 and in 1967, after months of testing, they were impressed enough to bulk buy 400 of them for future missions. Contrary to those urban legends, NASA didn't commission the pen or contribute any funding to it. The Soviets soon ditched their grease pencils and were eventually buying the same Fisher pens as NASA, too. The price? After a 40 percent discount from Fisher, both space agencies were paying $2.39 a pen.

The Fisher Space Pens made their debut in 1968 on the Apollo 7 mission and have been involved in all manned missions since.

So, the short reason is that astronauts only used pencils when they were waiting for something better to come along. As soon as it did, they switched and never looked back. Even the Russians thought it was a good idea.

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