SETI “Wow!” Signal Wasn’t Chatty Aliens After All — It Was a Fizzing Comet

sk-2017_04_article_main_desktop (1)
Big Ear Radio Observatory

On Aug. 15, 1977 at 10:16 p.m. ET Ohio State University’s Big Ear radio telescope detected a curious signal from deep space. Nearly 40 years later, we finally know what caused it and, sadly, it’s not aliens.

For decades, the signal has been the strongest piece of “go-to” evidence that intelligent extraterrestrials are out there in our galaxy. When found by astronomer Jerry Ehman on that fateful night, the 72-second signal — that had been recorded on a computer printout — certainly stood out.

While pointing at three star systems called Chi Sagittarii in the constellation of Sagittarius, Big Ear had picked up a powerful burst of radio waves. To the untrained eye, the assortment of printed digits might not mean much, but as I wrote in 2016, those letters and numbers could hold the answer to the biggest question we’re currently asking of the universe: Are we alone?

The Big Ear printout contains a bunch of apparently random numbers and letters, but Ehman’s red pen circles a cluster of digits “6EQUJ5” with other circles around a “6” and “7” on separate columns. This particular code first uses the numbers 1-9 and then the alphabet A-Z to denote signal strength. As the burst suggests, the signal strength hit “6” and then blasted through the letters reaching a peak of “U” before subsiding back into the numerical scale at “5.” There was then a slight wave trailing the main signal (hence the circled “6″ and “7″). The wave profile of the “Wow!” signal is graphically envisaged here. (Discovery News, April 18, 2016)

Wow-signal-graphic-1
Maksim Rossomakhin

The maddening thing about the Wow! signal has always been a lack of replication. To science, one random signal in the dark proves nothing. It would be like trying to plot a trend line on a graph with one data point. More data is obviously needed and yet, since 1977, there’s been no other radio signal quite like it.

Curious, yes. Definite proof of chatty aliens? A solid nope.

So, when researching other possible causes of the Wow! signal that were also rare occurrences (but not aliens), Antonio Paris of St Petersburg College, Fla. (and an ex-analyst of the US Department of Defense), suggested that the signal might have been generated by one of two comets that serendipitously drifted into the line of sight of the Big Ear radio telescope.

In 1977, neither 266P/Christensen and 335P/Gibbs were known of (they were discovered in 2006 and 2008 respectively) and Paris calculated that both comets would have been in the right place in the sky when the Wow! signal was recorded.

What’s more, the Wow! signal has a frequency of 1420MHz — the same frequency that neutral hydrogen radiates at. Hydrogen is abundant in our universe, so this frequency is commonly observed in astronomy.

At first blush, observing in this frequency to look for alien transmissions might seem like a fool’s errand; if the universe is humming in hydrogen noise, why would aliens bother using that frequency to ping their extraterrestrial neighbors?

Through SETI logic, the frequency of neutral hydrogen might be used by advanced civilizations as a kind of interstellar water cooler. It is the most abundant signal in the universe, every intelligent life-form would know this. So why not use 1420MHz as THE frequency to communicate across the light-years in hopes that other civilizations might already be tuned in?

But a SETI signal would need to stand out from the crowd — it would need to be powerful and possess other qualities that hint at its artificial nature. But should a comet quickly pass through the observing window of a radio telescope, Paris predicted that the received 1420MHz signal might mimic that of an artificial source.

And this year, an opportunity presented itself. Comet 266P/Christensen would pass through the sky in a similar orbital position as it did in 1977. During an observing campaign from November 2016 to February 2017, Paris studied the radio frequencies coming from the region and from the comet itself. He also compared these observations with other known comets.

The upshot: 266P is indeed producing a strong 1420MHz signal, as are other comets.

“The results of this investigation, therefore, conclude that cometary spectra are detectable at 1420 MHz and, more importantly, that the 1977 “Wow!” Signal was a natural phenomenon from a solar system body,” he writes in a study published in the Journal of the Washington Academy of Sciences

It appears that, in this case, the signal wasn’t aliens trying to make contact with us; it was a chance comet that just happened to be in the right place at the right time.

So, back to that alien megastructure

kotm-xfiles-poster-full
Fox
Advertisements

Astroengine Roundup: Time Machines, Stealth Solar Eruptions, Comet Oxygen

As I freelance for other websites, I thought I’d begin posting links and summaries here on a quasi-regular basis so you can keep up with the other space stuff I write about. So, to kick off the Astroengine Roundup, here you go:

Using TARDIS to Mathematically Travel Through Time (HowStuffWorks.com)

time-travel
HowStuffWorks

Ever since H. G. Wells wrote “The Time Machine” in 1895, we’ve been fascinated with the possibility of magically bouncing around through history. But it wasn’t until Einstein published his historic theory of general relativity that scientists (and science fiction writers) realized that time wasn’t necessarily as ridged as classical theories predicted. After a thought-provoking chat with general relativity expert Ben Tippett, of the University of British Columbia, I was able to get the lowdown on his mathematical model of a time machine called… TARDIS.

Comets Are Oxygen Factories (HowStuffWorks.com)

comet
ESA

When Europe’s Rosetta mission discovered molecular oxygen venting from comet 67P/Churyumov-Gerasimenko in 2015, scientists were weirded out. In space, molecular oxygen (O2, i.e. the stuff we breathe) is highly reactive and will break down very quickly. The working theory was that the O2 had been locked in the comet’s ices for billions of years since the solar system’s earliest moments, but new research suggests that 67P is actually producing its own O2 right this moment from a complex interplay between the venting water molecules and chemicals on the comet’s surface. Yes, comets are therefore molecular oxygen factories.

Not So Fast: Magnetic Mystery of Sun’s ‘Stealth’ Eruptions Uncovered (SPACE.com)

stealthcme2a
NASA’s Goddard Space Flight Center/ARMS/Joy Ng

Coronal mass ejections, or CMEs, are the most dramatic eruptions that our sun can produce. If they are Earth-directed, these magnetized bubbles of superheated plasma can cause all kinds of issues for our high-technology civilization. Usually, space weather forecasters do a great job of at least predicting when these eruptions might be triggered in the sun’s lower corona, but there’s a different type of CME — the so-called “stealth” CME — that appears to come out of nowhere, created by the complex interplay of magnetic fields high in the sun’s atmosphere.

NASA Competitions (SPACE.com: 1, 2)

level1cylinder_plastic_and_dust

There’s been a couple of updates from NASA challenges and competitions these last few days. The first was the announcement of the High Performance Fast Computing Challenge (HPFCC), which challenges coders with some time on their hands to better optimize supercomputer software for NASA’s simulations of aeronautics models. The second was the announcement of the first winners of Phase 2 of NASA’s 3D-Printed Habitat Challenge — a competition that hopes to pull in talent from a range of backgrounds to ultimately develop the technology to 3D print habitats on Mars and beyond.

~Ad astra

When Stardust Met Tempel, a Love Story

Comet Tempel 1 near Stardust-NExT close approach (NASA)
Comet Tempel 1 near Stardust-NExT close approach (NASA)

A NASA spacecraft, a lonely comet and a Valentine’s date with no comparison.

Last night, NASA’s veteran Stardust-NExT mission successfully visited its second comet, Tempel 1. Having already been visited by NASA’s Deep Impact mission in 2005, it’s hard not to wonder whether Tempel 1 was a little apprehensive. Deep Impact did lob a refrigerator-sized copper impactor into the comet’s surface during the 2005 encounter, so I think we can forgive the comet some pre-date jitters.

Fortunately, Stardust was the perfect date (no impactors, silverware, dishes or bottles were thrown), just a peaceful flyby, during which the spacecraft beamed dozens of photos back to Earth. To quote Joe Veverka, Stardust-NExT principal investigator: “It was 1,000 percent successful!”

Alas, although the date was a success, there won’t be the sound of wedding bells any time soon. Stardust is now powering away from the comet at a breakneck speed. Was it something Tempel 1 said?

For more on this Valentine’s rendezvous, have a read of my Discovery News article “Stunning Photos from a Comet Near-Kiss.”

Oh yes, and I got bored, so I created a rough animation of the flyby. Enjoy!

Could P/2010 A2 be the First Ever Observation of an Asteroid Collision?

Something rather bizarre was observed in the asteroid belt on January 6. Ray Villard at Discovery News has just posted an exciting article about the discovery of a comet… but it’s not your average, run-of-the-mill kinda comet. This comet appears to orbit the Sun, embedded in the asteroid belt.

Comets don’t usually do that, they tend to have elliptical and inclined orbits, orbits that carry them close to the Sun (when they start to heat up, creating an attractive cometary tail as volatile ices sublimate into space, producing a dusty vapor). They are then flung back out into the furthest reaches of the Solar System where the heating stops and the comet tail disappears until the next solar approach.

But P/2010 A2 — discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) sky survey — has a circular orbit and it still appears to be venting something into space.

P/2010 A2 (LINEAR): A comet or asteroid debris? (Spacewatch/U of Arizona)

There is the possibility that it is a member of a very exclusive bunch of objects known as main belt comets (MBCs). MBCs are confused asteroid/comet hybrids that appear to spontaneously vent vapor and dust into space and yet stay confined to the asteroid belt. But, if P/2010 A2 is confirmed to be one of these, it will only be the fifth such object to be discovered.

So what else could it be? If the potential discovery of an MBC doesn’t excite you enough, it could be something else entirely: the dust produced by a hyper-velocity impact between two asteroids. If this is the case, it would be the first ever observation of an asteroid impact in the Solar System.

The asteroid belt isn’t the same asteroid belt you might see in science fiction; although there are countless rocky bodies in our asteroid belt, it is rare that these rocky bodies encounter each other. Space is very big, and although the density of asteroids in this region might be considered to be “high”, this is space we’re talking about, you can fly a spaceship through the region without having to worry that you’ll bump into something. The average distance between asteroids is huge, making it a very rare occurrence any two should hit. But given enough asteroids, and enough time, eventually asteroid collisions do happen. And in the case of P/2010 A2, we might have been lucky.

Asteroid collisions: Rare, but possible.
Asteroid collisions: Rare, but possible.

The chatter between comet/asteroid experts is increasing, and on one message board posting, Javier Licandro (Instituto de Astrofísica de Canarias, Spain) reports observing a secondary asteroid traveling with the cloud-like P/2010 A2.

The asteroid moves in the same direction and at the same rate as the comet,” reports Licandro on The Minor Planet Mailing List. “In addition, the P/2010 A2 (LINEAR) image does not show any central condensation and looks like a ‘dust swarm’.”

A short lived event, such as a collision, may have produced the observed dust ejecta.”

Therefore, this ‘comet’ may actually be the debris that was ejected after a collision between two asteroids. Although these are preliminary findings and it’s going to take some serious observing time to understand the true nature of P/2010 A2, it’s exciting to think that we may just have observed an incredibly rare event, 250 million miles away.

Source: Discovery News

Laboratory Ice Links Comets with Life On Earth

Artist impression of the nucleus of Comet Tempel (NASA)

It is an established theory that comets may have, in some way, seeded life on Earth. Some extreme ideas support the panspermia concept (where bacterial organisms hitched a ride on comets, asteroids or some other planetary debris, spreading life throughout the Solar System), while others suggest comets may have contributed the chemical building blocks essential for life to form 4 billion years ago. We know these icy bodies are also awash with organic compounds, so it’s not a huge leap of the imagination to think comets may have donated life-making material to the early Earth.

In an effort to study cometary material and its possible influence for nurturing early life on Earth, Prof. Akiva Bar-Nun of the Department of Geophysics and Planetary Sciences at Tel Aviv University has been creating his own comets in the laboratory. By doing this, Bar-Nun is hoping to gain a better perspective on how comets acquired their composition of the noble gases Argon, Krypton and Xenon.

The proportion of these elements are found in the Earth’s atmosphere, but are not thought to have originated from the rocky material our planet consists of. By understanding the proportions of these elements that formed in the icy laboratory environment, if the proportions match that of what we’ve measured on Earth, it goes to some way in explaining how comets formed in space and how they delivered organic compounds to the surface.

Now if we look at these elements in the atmosphere of the Earth and in meteorites, we see that neither is identical to the ratio in the sun’s composition,” said Bar-Nun. “Moreover, the ratios in the atmosphere are vastly different than the ratios in meteorites which make up the bulk of the Earth.”

So we need another source of noble gases which, when added to these meteorites or asteroid influx, could change the ratio. And this came from comets.”

Prof. Bar-Nun and his team carried out the research using a comet-making machine unique to Tel Aviv University, and although the original press release is light on the details, it is assumed the chemical composition of the early Solar System was recreated and then deep-frozen.

Comets bombarded the Earth 4 billion years ago. Organic chemicals were therefore deposited, possibly kick-starting life (NASA)
Comets bombarded the Earth 4 billion years ago. Organic chemicals were therefore deposited, possibly kick-starting life (NASA)

Comets formed some distance from the Sun (and a vast number of them populate the Oort Cloud), water vapour would have condensed and frozen, in temperatures as low as -250°C, trapping a primordial collection of chemicals inside their dusty, icy interiors. Some time after, these comets may have fallen into the inner Solar System, many impacting the Earth. Amino acids may have been introduced to the surface and oceans, or vital chemical components from the comets combined with chemicals already on Earth and life was sparked. When this happened, these comets would have left a chemical fingerprint.

Bar-Nun’s team were successful in creating their own synthetic comet, freezing water vapour, creating a natural ratio between the three elements. Then a link could be made, from the laboratory comet, with the very definite noble gas proportions, and the proportions of these gases found in the atmosphere.

The pattern of trapping of noble gases in the ice gives a certain ratio of Argon to Krypton to Xenon, and this ratio — together with the ratio of gases that come from rocky bodies — gives us the ratio that we observe in the atmosphere of the Earth,” added Bar-Nun.

Judging by the information available (the paper is published in the journal Icarus), Bar-Nun’s research has provided evidence that comets left a unique ratio of stable noble gases in the atmosphere, a ratio of necessary materials for life to eventually form.

Source: Tel Aviv University, EurekAlert via @Avinio

Tonight’s Paranormal Radio Show Postponed

Tonight for my monthly Paranormal Radio slot, Captain Jack and I will be having a discussion about the threat of asteroids and comets to the Earth. It’s not a question of if we’ll get hit by an extinction-level event, it’s a question of when

Due to technical problems with the “voice of darkness” in the depths of Texas, tonight’s show about asteroids and interplanetary shooting galleries will have to be postponed for a couple of days. I hope it’s got nothing to do with those damn aliens or 2012 activists… Anyhow, for some reason Jack had to drive to Dallas, breaking all sorts of land-speed records, to buy a server…?!

Watch this space, I’ll update you with news as I get it…

In the mean time, check out the breadth of news items about space, politics, conspiracies, big foot and ghostly happenings at WPRT Radio

Why Can’t we see the Oort Cloud?

Hubble Space Telescope observation of Polaris – looking through the Oort Cloud, but not resolving any comets (Hubble)

The Oort Cloud is a mysterious entity. Located on the outskirts of the Solar System, this hypothetical region is probably the source of the long-period comets that occasionally pass through the inner planets’ orbits. The strange thing about these comets is that they have orbits inclined at pretty much any angle from the ecliptic which suggests their source isn’t a belt confined to the ecliptic plane (like the asteroid belt or Kuiper belt). Therefore, their proposed source is a cloud, acting like a shell, surrounding the Solar System.

OK, so we think the Oort Cloud is out there, and there is a lot of evidence supporting this, but why can’t we see the Oort Cloud objects? After all, the Hubble Space Telescope routinely images deep space objects like stars, galaxies and clusters, why can’t we use it to see embryonic comets within our own stellar neighbourhood?
Continue reading “Why Can’t we see the Oort Cloud?”