In this age of persistent surveillance and awareness (I’m not talking about people, but of weather, seismic events, astronomy and the like), an age where we are examining both subatomic particles and planets orbiting distant stars, it’s easy to forget there’s a heck of a lot we don’t know.
In many cases, we know what we don’t know, and we pour lots of time and energy into exploration, testing theories that either fall flat, or result in groundbreaking discoveries such as the measurable existence of gravitational waves. In other cases, mysteries are lurking right under our proverbial noses, ignored because we assume we know more than we do.
For example, I’m fascinated by the recent “discovery” of STEVE, the long (600-miles or so) narrow, straight band of purplish light that occurs in polar climes. I put “discovery” in quotes because the existence of STEVE is well known, and has been observed for a long time – but collectively we all assumed it was a type of aurora (aka Northern Lights, Southern Lights, etc). For years, STEVE was just a slightly off-color, strangely shaped example of something we knew very well. Then, scientists at the University of Calgary (Canada) and University of California (United States) decided to take a closer look. The result, as documented in and August, 2018 paper in the journal Geophysical Research Letters, is that STEVE is something completely unknown to science.
In a statement by the American Geophysical Union (AGU), lead author Bea Gallardo-Lacourt says, “Our main conclusion is that STEVE is not an aurora. So right now, we know very little about it. And that’s the cool thing, because this has been known by photographers for decades. But for the scientists, it’s completely unknown.”
Aurora chasers have been calling the phenomenon “Steve”, in a reference to the 2006 film Over the Hedge, in which the character Hammy suggests calling the hedge Steve, because “Steve is a nice name.” Though this isn’t a very scientific term, the scientists studying the phenomenon kept it, while turning it into an official acronym – “Strong Thermal Emission Velocity Enhancement”. This by itself is pretty cool, and shows that scientists have a pretty good sense of humor!
Auroras occur when streams of high-energy charged plasma particles from solar Coronal Mass Ejections (CME) strike the Earth’s upper atmosphere and energize high-altitude oxygen and nitrogen gas molecules, which emit light in predominately red and green wavelengths. Because these particles are charged (ionized) to begin with, they interact with Earth’s magnetic field and get funneled into the magnetic poles, and thus are concentrated in the higher latitudes.
However, the study found that STEVE does not contain the telltale charged particles that auroras do. It’s completely different, marked instead by a narrow band of high-velocity, extremely hot (though still diffuse, at about 200 miles above the surface) gas. This jet is about 5,500 degrees F (3,000 degrees C) hotter and 500 times faster than the surrounding air – and we still don’t know where it comes from, or why it glows the way it does.
So, we have an unexplored, unknown phenomenon right here close to home, in our own atmosphere, that people have openly discussing for decades, and doubtless watching for millennia. This makes me oddly happy, reminding me that there is ALWAYS something new to learn, even about things we thought we understood.
I’m looking forward to learning more about STEVE, and the additional mysteries that it leads us to. As Einstein was purported to say, “The more I learn, the more I realize how much I don’t know.”
Get Out There