Way Down South, the Sixth

I’ve just arrived at the South Pole for the sixth time (as in 4 hours ago, so I’m pretty oxygen deprived. Please excuse any hypoxia-induced typos). The set of things in my life that have just become normal (I have a favorite breakfast on a continent I don’t even live on) is strange.

Anyhow, not much to say right now, but I wanted to document my trip down from Christchurch. We fly from Christchurch to McMurdo Station, just off the coast of Antarctica, and then onward to the South Pole. The flights are all on military aircraft. At the beginning and the end of the summer season, the runways in McMurdo are hard enough to land wheeled aircraft, so we get to fly in C-17s. The C-17 is a large, jet-engined cargo plane. It makes the flight in about 5 hours. At this time of the year, we have to use LC-130s, since they have skis. The LC-130 is a smaller, propeller driven plane. Similar to the small commuter planes that hop between nearby airports in the US. They take 8 hours of noise and discomfort to get to McMurdo. You may be able to guess which plane I prefer to fly.

It’s not unusual for flights to be delayed, or outright canceled. Predicting the weather is extremely difficult, and the planes are old. This time down was fairly smooth, as opposed to last year when I was “stuck” for 5 days in Christchurch. We were only an hour late departing for McMurdo, and the flight was reasonably smooth. Upon our arrival, we were informed that we’d be heading out for the flight to Pole at 15:45 the next day. However, we discovered at 9:15 that our departure time had been bumped up to 9:55. Of course, we all scrambled to leave, and track down anyone else who was supposed to go (not an easy feat without cell phones). Some time between 9:20 and 9:35, the departure was pushed back to 10:45. About an hour later, it was back to 15:45, so I went on a hike. 15:30 rolls around, and I check to make sure we’re still going, then go to pack up a few last minute items. 3 minutes later, we find out there’s a 2 hour delay. In my mind, this isn’t the worst thing in the world, since it means we’ll get dinner in McMurdo, rather than whatever we can shove in our pockets to eat on the plane. Finally, 17:37 rolls around, so I head out to meet the bus that will take us to the plane. In the 4 minutes it takes me to walk from my room to the check-in, the flight has been canceled entirely.

The next day, we did go out to the plane on time, get in and take off, but we had to turn around about 10 minutes later (the navigation system had failed). Fortunately, there was another plane on the ground, and the mechanics were fairly certain they’d fixed the landing gear problem, so we got on that one. As luck would have it, it made it all the way to Pole.

I would say that trip is about average for delays and turnarounds (“boomerangs” as we call them). I’ve had worse, and I’ve had better. This time around, I at least have a C-17 flight to look forward to on the Northbound side.

I’ll try to post some pictures later.

I’m Back!

Way Down South, Again

So, I’m back at the South Pole again. It’s been just under two years since
my last trip, and a lot has changed. First of all, I’m no longer a
freelancing scientist-for-hire. In the Fall of 2015 I started a
PhD. program at UC Berkeley. As such, I’ve had less time to run around and
do fun stuff (hence the two year gap between visits to Pole). However, I
think I spent the time pretty well. I’ve been helping to build parts of the
SPT-3G receiver that we are currently deploying.

SPT-3G (for 3rd generation) is a brand new camera we are currently preparing
to mount on the telescope. The instrument capabilities and science goals
are largely similar to the SPTpol instrument I worked on for 4 years.
However, SPT-3G has 10 times as many detectors (about 16,000, in total). By
the end of the survey, the increased detector count should allow us to do
some very interesting science. I don’t have time to go into all of it now,
but I want to mention one topic I’m very excited about.

One of the primary goals for SPT has always been to find massive clusters of
galaxies. The superheated gas in these clusters is hot enough to interact
with the CMB photons. This leaves a distinct imprint at the location of
each cluster when we look at the sky. Massive galaxy clusters are of
particular interest, because they can tell us quite a lot about how
structure formed in the universe. However, to get to that point, we need
the mass of the galaxy clusters.

Current methods (based on a X-ray observations) lead to a 10-20% error in
the mass estimate, which is pretty limiting to our ability to make
definitive statements about the growth of structure. However, SPT-3G has the
potential to improve those measurements. Galaxy clusters are so heavy that
they bend light (much like a black hole), including the CMB. By looking for
these small shifts of the background radiation, it is possible to tell how
much a foreground object weighs. This measurement is very hard to do, since
the bending is very subtle, and we don’t know exactly what the background
should look like before it is distorted. But, by looking at hundreds or
thousands of galaxy clusters, we can determine the average mass, and use
additional observables to back out the mass of each cluster. In the next 10
years this technique should give us 2-3% errors on cluster mass.

So, there you have it, a quick introduction to SPT-3G. This has been a huge
project for the entire group, and everyone has been working way too many
hours. But, things are getting close. If we’re lucky, we’ll be seeing
first light in the next 36 hours.

Stories from the Southbound Voyage

I’m running out of satellite and brain power now, so I’m just going to dump
a couple pictures with brief stories here.

Nathan and a Tree
Nathan with a tree

We took a very pleasant walk through the botanical gardens on our first day in Christchurch. Nathan thought that the Ponderosa Pines didn’t smell right.

The top of Ob Hill
The top of Ob Hill, outside McMurdo
MucMurdo from the top of Ob Hill
McMurdo from the top of Ob Hill, featuring Sasha

On the way through McMurdo, I climbed the small hill right outside of town
for the first time. It is called Observation Hill (shortened to Ob Hill),
as it gives you a really good vantage point over the surrounding area. The
top has a small memorial to the Scott expedition that failed to return from
the South Pole in 1912.

Oh, Look!

As I was finishing up this post, we got some data coming live from the
camera. Check it out!

Each little blob is a
set of 6 detectors. The orange ones are currently under test, and the plots
in the bottom right show the real time data coming from one of the
detectors. The wiggly bit is the result of the particular test we are
doing.

Sunrise Pictures

This is just a quick post to show off some of my recent pictures. The sun is almost up (the official sunrise is in 5 days). So far, most of the colors have been obscured by clouds. We’ve only had a few days of clear weather, and even those had clouds on the horizon.

The first occurence of real color on the horizon.
One of the first truly bright days. I used my camera’s flash to illuminate the telescope. Unfortunately, this caused some of the snow in the air to reflect back to my lens, leading to the vague bright spots all over.
This picture was taken a few days later. The light from the sun is much brighter, which means my flash was not as effective.
This is almost the same picture as the last one. However, for this version I did not use the flash. In post processing, I changed the exposure and black point to make the telescope appear as a silhouette.