Listening to Winds On Alien Worlds Is More Complicated Than it Sounds

InSight’s recording of Martian winds isn’t what you’d hear if you were on the planet yourself

Artist’s impression of the European Huygens lander that descended through Titan’s atmosphere and landed on the Saturn moon’s surface [ESA]

We live in a world where spacecraft are now routinely landing on other worlds and recording their sounds. Soviet probes aimed at Venus captured the thunder and howling winds on the volcanic world, giving us the first ever audio recording captured beyond Earth. We’ve been able to reconstruct the sound of alien rain on Saturn’s moon Titan. And now, for the first time, we get to hear the low hum of Martian winds sweeping down the planes. Except not exactly. You see, while InSight did in fact record a 10 to 15 mile per hour draft on Martian, the recording’s pitch had to be dialed up and its frequency sped up roughly 100 times for the human ear to make any real sense of it. But why is it so hard to hear them otherwise?

Unlike Venus or Titan, Mars has an extremely thin, barely there atmosphere stripped away by solar winds and with virtually no protection from its weak magnetosphere. It’s so thin and fragile that it might actually make the planet impossible to terraform if we ever wanted to try to make it even a little more like our world. Even hurricane force winds would feel like a gentle breeze because there’s just not enough air to impart any meaningful kinetic energy. So, if you were able to stand on the surface of Mars without a spacesuit, you’d probably hear and feel nothing, hence NASA had to help us out so we could get some appreciation of what they were able to record, which is still exquisitely haunting and beautiful in the end.

What about winds on other planets and moons?

With extremely thick atmospheres, you’d have absolutely no problem hearing and feeling the full force of the wind on worlds like Venus, Jupiter and the other gas giants, and of course, Titan. In the turbulent clouds of gas giants, the winds would never stop and without anything solid to act as a brake, gusts can howl at astonishing speeds. Neptune boasts the fastest winds in the solar system at 1,200 miles per hour, with Saturn not far behind as 1,118 mile per hour gales whip around its equator, making Jupiter seem almost inert by comparison with peak wind speeds of 384 miles per hour around its Great Red Spot.

Exactly how hard that wind would hit you will depend on your altitude in the gas giants’ vast atmospheres but analogies with the impacts of anything between a tornado and a freight train come to mind. At this point, we would consider the kinetic energy of winds on Venus and Titan because they have solid surfaces and very thick atmospheres, but on both worlds, a very odd and interesting thing happens as you descend through the clouds. That atmospheric thickness means that gasses are compressed as you get close and closer to the surface and winds very quickly die down under the mass of the air through which they have to move.

On Titan, winds reach maybe 2 miles per hour at ground level at their strongest. On Venus, they peak at 3 miles per hour. Still, because there’s so much mass in motion, they would feel like a stiff breeze of 20 to 25 miles per hour if we note that the gusts in question are strong enough to scatter small rocks and use the Beaufort scale to translate that into comparable conditions right here on Earth. You would certainly hear it as well, deeper and more ominous than you’d expect, with absolutely no need to increase the pitch or speed up frequency for your ear to know what’s happening.

So, in case you ever look at the night sky and wonder about how different other planets are from the one on which you’re standing, consider that something seemingly as simple as the sound of moving air can be vastly different from world to world, what you’d consider a gentle breeze could be imperceptible on one planet and blow an umbrella out of your hand on another, and that sometimes, to appreciate what our robotic probes are detecting, we need to specially process the data they’ve gathered so you can even start making sense of it.

[This article originally appeared on World of Weird Things]

Smallest ‘Super-Earth’ Discovered With an Atmosphere — but It’s No Oasis

MPIA

For the first time, astronomers have detected an atmosphere around a small (and likely) rocky exoplanet orbiting a star only 39 light-years away. Although atmospheres have been detected on larger alien worlds, this is the smallest world to date that has been found sporting atmospheric gases.

Alas, Gliese (GJ) 1132b isn’t a place we’d necessarily call “habitable”; it orbits its red dwarf a little too close to have an atmosphere anything like Earth’s, so you’d have to be very optimistic if you expect to find life (as we know it) camping there. But this is still a huge discovery that is creating a lot of excitement — especially as this exo-atmosphere has apparently evolved intact so close to a star.

The atmosphere was discovered by an international team of astronomers using the 2.2 meter ESO/MPG telescope at La Silla Observatory in Chile. As the exoplanet orbited in front of the star from our perspective (known as a “transit”), the researchers were able to deduce the physical size of the world by the fraction of starlight it blocked. The exoplanet is around 40 percent bigger than Earth (and 60 percent more massive) making it a so-called “super-Earth.”

Through precision observations of the infrared light coming from the exoplanet during the 1.6 day transits, the astronomers noticed that the planet looked larger at certain wavelengths of light than others. In short, this means that the planet has an atmosphere that blocks certain infrared wavelengths, but allows other wavelengths to pass straight through. Researchers of the University of Cambridge and the Max Planck Institute for Astronomy then used this information to model certain chemical compositions, leading to the conclusion that the atmosphere could be a thick with methane or water vapor.

Judging by the exoplanet’s close proximity to its star, this could mean that the planet is a water world, with an extremely dense and steamy atmosphere. But this is just one of the possibilities.

“The presence of the atmosphere is a reason for cautious optimism,” writes a Max Planck Institute for Astronomy news release. “M dwarfs are the most common types of star, and show high levels of activity; for some set-ups, this activity (in the shape of flares and particle streams) can be expected to blow away nearby planets’ atmospheres. GJ 1132b provides a hopeful counterexample of an atmosphere that has endured for billion of years (that is, long enough for us to detect it). Given the great number of M dwarf stars, such atmospheres could mean that the preconditions for life are quite common in the universe.”

To definitively work out what chemicals are in GJ 1132b’s atmosphere, we may not be waiting that long. New techniques for deriving high-resolution spectra of exoplanetary atmospheres are in the works and this exoplanet will be high on the list of priorities in the hunt for extraterrestrial biosignatures. (For more on this, you can check out a recent article I wrote for HowStuffWorks.)

Although we’ll not be taking a vacation to GJ 1132b any time soon, the discovery of an atmosphere around such a small alien world will boost hopes that similar sized super-Earths will also host atmospheres, despite living close to red dwarf stars that are known for their flaring activity. If atmospheres can persist, particularly on exoplanets orbiting within a star’s so-called habitable zone, then there really should be cause for optimism that there really might be an “Earth 2.0” out there orbiting one of the many red dwarfs in our galaxy.

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!