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

NASA/JPL-Caltech
NASA/JPL-Caltech

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, Space.com 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.

[h/t Space.com]

A Super Pink Moon—the Biggest Supermoon of 2020—Is Coming In April

April's super pink moon will be extra big and bright (but still white).
April's super pink moon will be extra big and bright (but still white).
jakkapan21/iStock via Getty Images

The sky has already given us several spectacular reasons to look up this year. In addition to a few beautiful full moons, we’ve also gotten opportunities to see the moon share a “kiss” with Venus and even make Mars briefly disappear.

In early April, avid sky-gazers are in for another treat—a super pink moon, the biggest supermoon of 2020. This full moon is considered a supermoon because it coincides with the moon’s perigee, or the point in the moon’s monthly orbit when it’s closest to Earth. According to EarthSky, the lunar perigee occurs on April 7 at 2:08 p.m. EST, and the peak of the full moon follows just hours later, at 10:35 p.m. EST.

How a supermoon is different.

Since the super pink moon will be closer to Earth than any other full moon this year, it will be 2020’s biggest and brightest. It’s also the second of three consecutive supermoons, sandwiched between March’s worm moon and May’s flower moon. Because supermoons only appear about 7 percent bigger and 15 percent brighter than regular full moons, you might not notice a huge difference—but even the most ordinary full moon is pretty breathtaking, so the super pink moon is worth an upward glance when night falls on April 7.

The meaning of pink moon.

Despite its name, the super pink moon will still shine with a normal golden-white glow. As The Old Farmer’s Almanac explains, April’s full moon derives its misleading moniker from an eastern North American wildflower called Phlox subulata, or moss pink, that usually blooms in early April. It’s also called the paschal moon, since its timing helps the Catholic Church set the date for Easter (the word paschal means “of or relating to Easter”).

[h/t EarthSky]

Are Any of the Scientific Instruments Left on the Moon By the Apollo Astronauts Still Functional?

Apollo 11 astronaut Neil Armstrong left the first footprint on the Moon on July 20, 1969.
Apollo 11 astronaut Neil Armstrong left the first footprint on the Moon on July 20, 1969.
Heritage Space/Heritage Images/Getty Images

C Stuart Hardwick:

The retroreflectors left as part of the Apollo Lunar Ranging Experiment are still fully functional, though their reflective efficiency has diminished over the years.

This deterioration is actually now delivering valuable data. The deterioration has multiple causes including micrometeorite impacts and dust deposition on the reflector surface, and chemical degradation of the mirror surface on the underside—among other things.

As technology has advanced, ground station sensitivity has been repeatedly upgraded faster than the reflectors have deteriorated. As a result, measurements have gotten better, not worse, and measurements of the degradation itself have, among other things, lent support to the idea that static electric charge gives the moon an ephemeral periodic near-surface pseudo-atmosphere of electrically levitating dust.

No other Apollo experiments on the moon remain functional. All the missions except the first included experiment packages powered by radiothermoelectric generators (RTGs), which operated until they were ordered to shut down on September 30, 1977. This was done to save money, but also because by then the RTGs could no longer power the transmitters or any instruments, and the control room used to maintain contact was needed for other purposes.

Because of fears that some problem might force Apollo 11 to abort back to orbit soon after landing, Apollo 11 deployed a simplified experiment package including a solar-powered seismometer which failed after 21 days.

This post originally appeared on Quora. Click here to view.

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