Antarctica's Massive Neutrino Observatory Gets an Upgrade

There's already 5,000 sensors embedded in Antarctica's ice to look for evidence of neutrinos, reports the Washington Post. But in November scientists drilled six new holes at least a mile and a half deep and installed cables with hundreds more light detectors — an upgrade to the massive 15-year-old IceCube Neutrino Observatory to detect the charged particles produced by lower-energy neutrinos interacting with matter: When they do, the neutrinos produce charged particles that travel through the ice at nearly the speed of light, creating a blue glow called Cherenkov radiation... "Within the first couple years, we should be making much better measurements," [said Erin O'Sullivan, an associate professor of physics at Uppsala University in Sweden and a spokesperson for the project.] "There's hope to expand the detector, by an order of magnitude in volume, so the important thing there is we're not just seeing a few neutrino point sources, but we're starting to be a true telescope. ... That's really the dream."
The scientists spent seven years planning the upgrade, according to the article. "To drill holes a mile and a half deep takes about 30 hours, and 18 more hours to return to the surface," the article points out. "Then, the race begins because almost immediately, the hole starts to shrink as the water refreezes." ("If it takes too much time, the principal investigator says, "the instruments don't fit in anymore!")

The really cool possibility remains

[JoshuaZ]

The really cool possibility is that we may be able to use this to detect a supernova's neutrinos before the light arrives. This happened once before in 1987 https://en.wikipedia.org/wiki/SN_1987A [wikipedia.org] but in that case the supernova was very close and the tech was poor enough that we didn't realize the supernova neutrinos had arrived before hand until days after. If we could have this happen again we could know to point conventional optical telescopes at a supernova before the light arrived and get to see the first light from a supernova in detail which would be potentially highly informative. However, it is important to note that this doesn't work via neutrinos going faster than light in a vacuum. The OPERA experiment which seemed to show that a few years ago was in error. These neutrinos get there faster than light because they get a head start of a few hours, starting at the very beginning of the supernova from the star's core, while it takes light a few hours going out from the core bouncing off of the dense plasma. The neutrinos barely interact with any matter, so they don't get blocked the same way. Upgrading IceCube increases the chance that we'll get to see this with a somewhat far away supernova.

Re:

[BranMan]

So basically the explosion at the heart of a supernova produces light and neutrinos together. But the light itself is retarded while within the star, giving the neutrinos a several hour head start. "really cool" indeed [I see what you did there].

One thing to keep in mind is that once light escapes the star, both the light wavefront and the neutrino wavefront propagate at lightspeed. So the head start will be independent of the distance to the exploding supernova.

I hope the guys in Antarctica are on the "