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Dark matter remains one of the greatest mysteries in science.  Despite decades of astronomical evidence for its existence, no one has yet been able to find any sign of it closer to home.  There have been dozens of efforts to do so, and one of the most prominent just hit a milestone – the release and analysis of 8 years of data.  The IceCube Neutrino Observatory will soon be releasing results from those 8 years, but for now let’s dive in to what exactly they are looking for.

Theories abound about what dark matter actually is, and several of them focus on the idea of Dark Matter as a type of particle.  The most prominent of those is the Weakly Interacting Massive Particle (WIMP).  The physics behind WIMP are one of the primary drivers of the IceCube Experiment.

Video describing how IceCube works.
Credit – IceCube Neutrino Observatory YouTube Channel

A neutrino detector might seem like an odd way to look for WIMPs, but the physics behind it is well understood.  When traveling through large clumps of “standard model” matter (i.e. what we think of as “normal” particles), WIMPS could lose energy and eventually become gravitationally bound to the body they are traveling through.  This would be the case with planets, or with the Sun.  So the center of the Earth could harbor a large, unseen mass of weakly interacting particles.

It would be impossible to directly detect any such grouping of WIMPS.  However, scientists could see tell-tale signs by measuring a proxy particle – neutrinos.  Neutrinos, which themselves are notorious for being difficult to detect, result from some theories where WIMPs self-destruct by interacting with a standard particle.  Since they are so difficult to pin down, the neutrinos that would result from this process in any mass of WIMPs in the center of the Earth would almost certainly be able to make it through the mass of the Earth and out into space. 

Isaac Arthur video discussing the (known) properties of Dark Matter.
Credit – Isaac Arthur YouTube Channel

But along the way, they might get picked up by a neutrino detector, like IceCube. Based at the geographic South Pole, IceCube consists of 86 strings of digital optical modules containing 5160 individual optical sensors that will detect a type of light created by Cherenkov radiation when any neutrino interacts with another particle.  By triangulating the brightness and longevity of the light pulse, scientists can then backtrack the speed and direction that the neutrino was traveling.

Given the finicky nature of the equipment and its particle of interest, noise reduction is a key component of IceCube.  Part of that strategy is done via isolation – not only is the detection array based at one of the most isolated spots on Earth, it also is buried under 1450m of ice and spans almost a vertical kilometer in depth.  

Looking down one of IceCube's detector bore holes.
Looking down one of IceCube’s detector bore holes.
Credit: IceCube Collaboration/NSF

The other part of that strategy is based on simulations, particularly to estimate and eliminate background noise. The IceCube research team, which consists of scientists from all over the world, use simulations of background noise in an effort to eliminate false detections.  In addition, they are able to eliminate some source of neutrinos not associated with WIMPs, such as when the system detects a neutrino that is traveling towards Earth’s core rather than away from it. Most likely these types of neutrinos are caused by “atmospheric neutrinos” which are formed when cosmic rays hit Earth’s atmosphere.

All of this effort is toward one relatively simple task – trying to figure out what exactly WIMPs are.  In particle physics language, this means trying to put constraints on their “mass”.  As with many things in particle physics, it is measured slightly differently than by simply putting something on a scale.  Measured in “electron volts”, the researchers looked at potential masses between 10GeV (giga electron volts) to 10 TeV (tera electron volts).  These ranges include masses that are orders of magnitude “heavier” than other well known subatomic particles, such as the Higgs Boson (125 GeV) or electron (.511 MeV). 

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Does Betelgeuse Even Rotate? Maybe Not

Betelgeuse pulsating UV HST jpeg

Betelgeuse is the well known red giant star in the corner of Orion the hunter. The name translated in some languages means ‘armpit of the giant’ which I think of all the star names, is simply the best! Betelgeuse has been fascinating observers of late not only because it unexpectedly faded a few years ago but more recently a study shows it’s super fast rotational speed which is, when compared to other supergiants, is like nothing seen before. 

One of the brightest stars in the northern hemisphere sky, in fact the tenth brightest, Betelgeuse has a stunning red colour. It is a semi regular variable star which means there is some regularity to its varied light output but there are occasions, perhaps lasting between 20 and 2000 days where the variation is interrupted. If Betelgeuse were placed in the Sun’s position then its visible surface would more than likely extend beyond the orbit of Mars and swallow up everything in between. 

Image showing the variability of Betelgeuse
1998/9 UV HST images of Betelgeuse showing asymmetrical pulsations with corresponding spectral line profiles (Credit :  STScI, NASA, ESA)

Like all stars, Betelgeuse rotates but a recent study using the Atacama Large Milimeter Array (ALMA) has showed that Betelgeuse is rotating faster than expected. Cool stars like Betelgeuse expand as they evolve and to conserve momentum the rotation must slow.  It is possible that mass loss due to stellar winds decreases rotation speeds further. The current theory predicts that red giants rotate at around 1km per second while red supergiants a little less than 0.1km per second. 

Image showing two of the receivers of the ALMA array in the Atacama Desert.
Two of the Atacama Large Millimeter/submillimeter Array (ALMA) 12-metre antennas (Credit : Iztok Bon?ina/ESO)

Current theory aside it seems there have been a number of observations of at least a few hundred giant stars rotating faster. Betelgeuse in particular has shown faster than expected rotation. Somewhat usefully, it’s proximity to Earth has meant its surface can be resolved and accurate measurements taken. Measurements showed that half of the visible hemisphere was blue shifted and the the other half red shifted. We can use this information to accurately calculate a rotational velocity.

When it comes to Betelgeuse, the radial velocity with ALMA was measured to be around 5.47 km per second. This value was compared against previous observations using Hubble Space Telescope and thankfully this agreed. One leading theory takes binary star evolution as a possible cause and in particular a merger with a low mass companion star. This is not an unusual process with an expected one-third of red supergiants experience stellar merger before their core collapses marking the end of their life. When it comes to red giants the team considered the impact of merging with planetary systems on the rotational velocity.

There are complications however in attaining sufficient data but the team modelled 3D radiation hydrodynamic simulations of red supergiants with properties similar to Betelgeuse. Throwing a proverbial spanner in the works, the team suggest that it is possible that the observations could be wrong and false signals have been picked up from churning convective plasma at the surface rather than the rotation of the star itself!

In an attempt to ascertain if it is possible to accurately measure the rotational speed of red giants and supergiants they had to develop new processing techniques to establish predictions that they could compare with observations of Betelgeuse. The team finally conclude that to be able to establish without doubt that Betelgeuse and other red supergiants are rotating
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5 Reasons You Must Backpack the Teton Crest Trail

Wind4 016 jpg

By Michael Lanza

On my first backpacking trip on the Teton Crest Trail in Grand Teton National Park, camped on Death Canyon Shelf, a broad, boulder-strewn and wildflower-carpeted bench at 9,500 feet, I awoke to the sound of heavy clomping outside my tent. I unzipped the tent door to investigate—and saw a huge bull elk standing just outside my nylon walls.

As I’ve come to learn over more than 20 trips to the Tetons since that first one over three decades ago, that elk encounter symbolized just one of several compelling reasons why every backpacker should move the Teton Crest Trail to the top of their to-do list: the wildlife. Where it occurred illustrates another reason: After years of backpacking all over the United States—including the 10 years I spent as a field editor for Backpacker magazine and even longer running this blog—Death Canyon Shelf is still one of my all-time favorite backcountry campsites.

Wind4 016 1 jpg
Hi, I’m Michael Lanza, creator of The Big Outside, which has made several top outdoors blog lists. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here to learn how I can help you plan your next trip.

Watching the sunset from a campsite in the North Fork Cascade Canyon, Grand Teton National Park.
” data-image-caption=”Watching the sunset from a campsite in the North Fork Cascade Canyon on the Teton Crest Trail in Grand Teton National Park.
” data-medium-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?fit=200%2C300&ssl=1″ data-large-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?fit=683%2C1024&ssl=1″ src=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?resize=432%2C648&ssl=1″ alt=”Watching the sunset from a campsite in the North Fork Cascade Canyon, Grand Teton National Park.” class=”wp-image-36411″ style=”width:432px;height:648px” width=”432″ height=”648″ srcset=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?w=800&ssl=1 800w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?resize=200%2C300&ssl=1 200w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?resize=768%2C1152&ssl=1 768w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-090-A-campsite-on-the-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P.jpg?resize=683%2C1024&ssl=1 683w” sizes=”(max-width: 432px) 100vw, 432px” data-recalc-dims=”1″ />Watching the sunset from a campsite in the North Fork Cascade Canyon, Grand Teton National Park.

And I certainly consider the Teton Crest Trail one of the 10 best backpacking trips in America. It’s the one I keep going back to again and again. (Read about my most recent trip.)

I think the five reasons I lay out below will give you insights into questions you might have about this classic hike—and inspire you to go do it.

But know this important planning detail: The

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How to Get a Permit to Backpack the Teton Crest Trail

Tet19 047 Me on Teton Crest Trail copy cropped jpg

By
Michael Lanza

For
backpackers, the Teton Crest Trail really delivers it all: beautiful lakes,
creeks, and waterfalls, high passes with sweeping vistas, endless meadows of
vibrant wildflowers, a good chance of seeing wildlife like elk and moose, some
of the best campsites you will ever pitch a tent in, and mind-boggling scenery
just about every step of the way. And it’s a relatively beginner-friendly trip
of 40 miles or less, which most people can hike in four to five days.

No wonder it’s so enormously popular—and there’s so much competition for backcountry permits.

In this story, I will offer tips on how to maximize your chances of getting a permit to backpack the Teton Crest Trail, sharing expertise I’ve acquired from more than 20 trips in the Tetons and several on the Teton Crest Trail over more than three decades, including the 10 years I spent as Northwest Editor of Backpacker magazine and even longer running this blog.

Tet19 047 Me on Teton Crest Trail copy cropped 1 jpg
Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-guides to classic backpacking trips. Click here to learn how I can help you plan your next trip.

Lake Solitude, North Fork Cascade Canyon, Grand Teton National Park.
” data-image-caption=”Lake Solitude in the North Fork of Cascade Canyon, Grand Teton National Park. Click photo for my e-guide “The Complete Guide to Backpacking the Teton Crest Trail.”
” data-medium-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?fit=900%2C600&ssl=1″ src=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?resize=900%2C600&ssl=1″ alt=”Lake Solitude, North Fork Cascade Canyon, Grand Teton National Park.” class=”wp-image-36414″ srcset=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?resize=1024%2C683&ssl=1 1024w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?resize=300%2C200&ssl=1 300w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?resize=768%2C512&ssl=1 768w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?resize=1080%2C720&ssl=1 1080w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2019/11/Tet19-095-Lake-Solitude-Teton-Crest-Trail-North-Fork-Cascade-Canyon-Grand-Teton-N.P..jpg?w=1200&ssl=1 1200w” sizes=”(max-width: 900px) 100vw, 900px” data-recalc-dims=”1″ />Lake Solitude in the North Fork of Cascade Canyon, Grand Teton National Park. Click photo for my e-guide “The Complete Guide to Backpacking the Teton Crest Trail.”

See my story from my most-recent trip on it, “A Wonderful Obsession: Backpacking the Teton Crest Trail,” which requires a paid subscription to The Big Outside to read in full, including basic information on planning a TCT backpacking trip. For much more information and expert tips on planning this trip, get my top-selling e-guide “The Complete Guide to Backpacking the Teton Crest Trail in Grand Teton National Park.”

I’ve also helped many readers plan a backpacking trip in the Tetons and elsewhere, answering all of their questions and customizing an itinerary ideal for them. See my Custom Trip Planning page to learn how
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