Screaming Exoplanets: Detecting Alien Magnetospheres

Exoplanets may reveal their location through radio emissions (NASA)
Exoplanets may reveal their location through radio emissions (NASA)

In 2009, I wrote about a fascinating idea: in the hunt for “Earth-like” exoplanets, perhaps we could detect the radio emissions from a distant world possessing a magnetosphere. This basically builds on the premise that planets in the solar system, including Earth, generate electromagnetic waves as space plasma interacts with their magnetospheres. In short, with the right equipment, could we “hear” the aurorae on extra-solar planets?

In the research I reviewed, the US Naval Research Laboratory scientist concluded that he believed it was possible, but the radio telescopes we have in operation aren’t sensitive enough to detect the crackle of distant aurorae. According to a new study presented at the RAS National Astronomy Meeting in Llandudno, Wales, on Monday, this feat may soon become a reality, not for “Earth-like” worlds but for “Jupiter-like” worlds.

“This is the first study to predict the radio emissions by exoplanetary systems similar to those we find at Jupiter or Saturn,” said Jonathan Nichols of the University of Leicester. “At both planets, we see radio waves associated with auroras generated by interactions with ionised gas escaping from the volcanic moons, Io and Enceladus. Our study shows that we could detect emissions from radio auroras from Jupiter-like systems orbiting at distances as far out as Pluto.”

Rather than looking for the magnetospheres of Earth-like worlds — thereby finding exoplanets that have a protective magnetosphere that could nurture alien life — Nichols is focusing on larger, Jupiter-like worlds that orbit their host stars from a distance. This is basically another tool in the exoplanet-hunters’ toolbox.

Over 500 exoplanets have been confirmed to exist around other stars, and another 1,200 plus exoplanetary candidates have been cataloged by the Kepler Space Telescope. The majority of the confirmed exoplanets were spotted using the “transit method” (when the exoplanet passes in front of its host star, thereby dimming its light for astronomers to detect) and the “wobble method” (when the exoplanet gravitationally tugs on its parent star, creating a very slight shift in the star’s position for astronomers to detect), but only exoplanets with short orbital periods have been spotted so far.

The more distant the exoplanet from its host star, the longer its orbital period. To get a positive detection, it’s easy to spot an exoplanet with an orbital period of days, weeks, months, or a couple of years, but what of the exoplanets with orbits similar to Jupiter (12 years), Saturn (30 years) or even Pluto (248 years!)? If we are looking for exoplanets with extreme orbits like Pluto’s, it would be several generations-worth of observations before we’d even get a hint that a world lives there.

“Jupiter and Saturn take 12 and 30 years respectively to orbit the Sun, so you would have to be incredibly lucky or look for a very long time to spot them by a transit or a wobble,” said Nichols.

By assessing how the radio emissions for a Jupiter-like exoplanet respond to its rotation rate, the quantity of material falling into the gas giant from an orbiting moon (akin Enceladus’ plumes of water ice and dust being channeled onto the gas giant) and the exoplanet’s orbital distance, Nichols has been able to identify the characteristics of a possible target star. The hypothetical, “aurora-active” exoplanet would be located between 1 to 50 AU from an ultraviolet-bright star and it would need to have a fast spin for the resulting magnetospheric activity to be detectable at a distance of 150 light-years from Earth.

What’s more, the brand new LOw Frequency ARray (LOFAR) radio telescope should be sensitive enough to detect aurorae on Jupiter-like exoplanets, even though the exoplanets themselves are invisible to other detection methods. Nice.

As we’re talking about exoplanets, magnetospheres and listening for radio signals, let’s throw in some alien-hunting for good measure: “In our Solar System, we have a stable system with outer gas giants and inner terrestrial planets, like Earth, where life has been able to evolve. Being able to detect Jupiter-like planets may help us find planetary systems like our own, with other planets that are capable of supporting life,” Nichols added.

Although Nichols isn’t talking about directly detecting habitable alien worlds (just that the detection of Jupiter-like exoplanets could reveal Solar System-like star systems), I think back to the 2009 research that discusses the direct detection of habitable worlds using this method: Aliens, if you’re out there, you can be as quiet as you like (to avoid predators), but the screaming radio emissions from your habitable planet’s magnetosphere will give away your location…

Crop Circles Do Not Predict Solar Storm on July 7th…

Stunning art, UFOs not included (© Lucy Pringle)
Stunning art, UFOs not included (© Lucy Pringle)

Alternative title: “Jumping to Conclusions and Bullshit”

Crop circles are amazing. They are, quite literally, works of art. And like all other known forms of art, they are constructed by people with time on their hands. No UFOs have been braiding our crops, no aliens have been playing let’s-confuse-the-stoopid-humans-with-this-cryptic-message-we-travelled-hundreds-of-light-years-to-deliver. Crop circles are made by hoaxers and enthusiasts.

So yesterday, I read a terribly fascinating, yet terribly painful article that seamlessly combines three disparate facts to arrive at a terribly flawed conclusion: a coronal mass ejection (CME) will hit us on July 7th, possibly causing global damage, according to a crop circle prediction.

This may seem a little shocking, considering this equivalent of a micro-doomsday is only two days from now, but the “Exopolotics Examiner” Dr. Michael Salla discusses it with great excitement:

The Alert is for Sunspot 1024 which suddenly appeared on July 3 and 4 […] It typically takes CMEs, traveling at around a million miles per hour, three to four days to reach the Earth. So if Sunspot 1024 does generate CMEs towards the Earth, they would arrive right on the predicted date of July 7.

Apparently, we now have an infallible space weather prediction method. Sunspot 1024 could generate a CME directed toward Earth, therefore fulfilling the prediction that we are going to get hit by a CME in two days. Amazing right? Obviously Salla is referring to the work of a solar physicist, with a new hi-tech computer simulation, or with access to cutting-edge observational data. Wow, it looks like we have found the Holy Grail of sunspot characterization methods!

(Guess again)

Actually, the July 7th prediction is purely based on crop circles at Milk Hill, in Wiltshire, UK. How do we know these flattened fields of corn predict a CME? Actually, they don’t. Even the crop circle experts make no convincing connection with crop circles and the Sun, apart from pointing out that the patterns resemble an orrery — but even if it is an orrery, the corn has been flattened by a team of hoaxers, they could make it mean anything. (I’m still waiting for a massive Micky Mouse crop circle.)

Although I find all this highly entertaining, the thing that made me laugh the most was the point that the Milk Hill patterns were made in “3 Phases.” However, looking at the incredibly beautiful design of that thing, it’s little wonder the aliens had to build the design in shifts. After all, extraterrestrials need tea-breaks too… perhaps their little feet got tired stomping all that corn… or perhaps it was constructed by slacking crop circle hoaxers who couldn’t get it all done in one night?

My money is on the latter.

So, there is a dubious link between the crop circle and the Sun (apart from ‘it faces that way,’ directly along the tractor tracks… hmm, interesting), what could Salla be talking about? Oh that’s it! The Earth’s magnetosphere has a hole in it! Hell, dig your lead-lined bomb shelters now!

Now this is one point I’m actually a little annoyed about. Apparently Dr. Salla is also qualified in solar-terrestrial physics, as he seems to dredge up some pretty compelling science recently published by NASA. Salla says:

Importantly, scientists will be able to directly study the impacts of large amounts of solar plasma penetrating a breach in the magnetosphere first reported by NASA scientists in December 2008 […] If the interpretations of crop circle researchers are correct, then we will shortly directly observe the impact of solar energy from CMEs passing through the magnetosphere breach. –Dr Salla (emphasis not added by me, used for dramatic effect I suspect).

Now this is good stuff, perhaps this guy is on to something. In summary:

  1. The Milk Hill crop circle predicts a solar storm on July 7th (but it’s not very clear where in the corn this is printed).
  2. An active sunspot has appeared at a high latitude on the solar surface (this is true, although only B Class solar flares have been detected… not in Earth-killing leagues I’m afraid).
  3. This sunspot could generate an Earth-directed CME (this is true, again, but the odds are pretty damn low).
  4. The CME will hit us on July 7th (read #3).
  5. Now that NASA has detected a hole in our magnetosphere, deadly solar particles could penetrate our atmosphere!

In other words, Salla has strung together some dubious “signs” from a crop circle, tied it into this new sunspot, gotten all excited that it could generate some pretty feeble CMEs, somehow assumed they will be Earth-directed and then chucked in a very incorrect opinion as to what this “hole in the magnetosphere” means.

Although the magnetospheric breach is certainly an amazing discovery — made by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites in 2008 — I think Salla misses the point. The magnetospheric breach hasn’t just appeared, it wasn’t caused by human activity (like the hole in the ozone layer, which I think he thinks this is), it’s always been there in some way, shape or form.

NASA’s five THEMIS spacecraft have discovered a breach in Earth’s magnetic field ten times larger than anything previously thought to exist. Solar wind can flow in through the opening to “load up” the magnetosphere for powerful geomagnetic storms. But the breach itself is not the biggest surprise. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.NASA release.

Obviously overcome with the NASA terminology “giant breach,” Salla assumes this is a new hole in the magntosphere leaving us open to the ravages of the Sun. Actually it doesn’t, it’s simply an observation of a previously unknown piece of magnetospheric dynamics. Yes, the breach is linked with solar storms and the aurora, but there’s every likelihood this phenomenon has always existed, even when the Earth’s magnetic field was battered by X-class solar flares and jumbo CME’s during the last solar maximum (are we still here? Yes, I think we are). To think we are going to even notice a make-believe low-energy CME produced by a feeble region of the Sun generating B-class solar flares is laughable.

So the physics is flawed, the prediction is totally far-fetched, and apparently you need a PhD in exopolitics to understand how crop circles come into it. It’s just a fear-mongering article that is becoming all too common on the Examiner these days.

No, this is another huge FAIL for the Examiner… where are all the Skeptical, Science and Common Sense Examiners?

Thank you @mactavish for reminding me to finish this article!

Listening Out for the Magnetospheres of Habitable Exoplanets

Searching for Earth-like exoplanets (© Mark Garlick)
Searching for Earth-like exoplanets (© Mark Garlick*)

Is there a new way to hunt for habitable Earth-like exoplanets? According to a US Naval Research Laboratory researcher there is an obvious, yet ingenious, way of listening for these worlds. Like most Earth-like exoplanet searches, we are looking for characteristics of our own planet. So what do we need to survive on Earth? Obviously we need water and the correct mix of oxygen with other atmospheric gases, but what about the magnetic bubble we live in? The Earth’s magnetosphere protects us from the worst the Sun can throw at us, preventing the atmosphere from being eroded into space and deflecting life-hindering radiation.

Although we have yet to develop sensitive enough radio telescopes, it may be possible in the future to detect the radio waves generated as charged particles in stellar winds interact with Earth-like exoplanetary magnetospheres. If there’s a magnetosphere, there may be a protected atmosphere. If there’s an atmosphere, perhaps there’s life being nurtured below

*This image is copyright Mark A. Garlick and has been used with permission. Please do not use this image in any way whatsoever without first contacting the artist.
Continue reading “Listening Out for the Magnetospheres of Habitable Exoplanets”

Standing Under the Aurora

Under an auroal display in 2004 above a Harstad (Norway) communications tower (NASA)
Under an auroal display in 2004 above a Harstad (Norway) communications tower (Frank Andreassen/NASA)

In 2002, I remember standing on the ice-crusted snow in Svalbard, looking up, in awe of what I was seeing. Dancing overhead, stretching from horizon to horizon was my first aurora. Predominantly green and highly structured against the inky black 24 hour night, the highly dynamic plasma danced, much like a curtain in the wind. Occasionally, I would see the ribbons of green scatter, forming a radiant pattern, much like today’s NASA Astronomy Picture of the Day (APOD), above.

Seven years ago, I was studying the interaction between the solar wind and the Earth’s upper polar atmosphere with four friends for five months at The University Centre in Svalbard, and it is an experience I’ll never forget. Seeing this dazzling view from a communications tower in northern Norway stirs some amazing memories of my stay on this unique island in the high arctic, watching the light generated as the solar plasma spiralled down Earth’s magnetic field, interacting with our atmosphere.

From that magical day onward, I never underestimated the beauty of physics again