[meteorite-list] View from the Summit: Hunting for KBOs at the Top of the World

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 5 Aug 2011 14:12:57 -0700 (PDT)
Message-ID: <201108052112.p75LCv7P020077_at_zagami.jpl.nasa.gov>

http://pluto.jhuapl.edu/news_center/news/20110805.php

View from the Summit: Hunting for KBOs at the Top of the World
John Spencer
New Horizons
August 5, 2011

John Spencer is a member of the New Horizons mission science team,
and the coordinator and self-described "cat-herder-in-chief" for the
effort to find a Kuiper Belt object flyby target for New Horizons.

I'd like to tell you a bit about our recent Kuiper Belt object search
observing run on the Subaru telescope on Mauna
Kea Observatory in Hawaii, one of a
dozen or so KBO search runs we're doing this year. But first, I want to
thank everyone who's helping out with the crucial task of sorting
through our terabytes of data for those elusive KBOs, using the Ice
Hunters <http://www.icehunters.org/> site! It's amazing the effort
people are putting into this, and I hope we can all reap the rewards
sometime in the coming decade, when we get mankind's first look at one
of the typical members of the Kuiper Belt.

I used to go to the telescope all the time, starting when I was a
postdoc at the University of Hawaii - Mauna Kea was where I learned the
ropes. But these days I spend most of my time working on space
missions - a thrilling business, but one where you do your "observing" at
your desk, or in teleconferences, or at meetings, thrashing out the
details of observations to be made millions of miles away and relayed
back to your computer for analysis after the fact. When I do use
Earth-bound telescopes these days, I usually do it over the Internet,
controlling the telescope from my desktop thousands of miles away.

For the KBO search effort, I've mostly been helping to plan observations
to be made by other teams, at the Subaru or Canada-France-Hawaii
telescopes in Hawaii, or at the Magellan telescopes in
Chile. So I was excited at the prospect of going back to Hawaii in
person for one of our Subaru runs. Even then, I expected to be
operating the telescope from a control room in Hilo at the base of the
mountain, not from the summit - it's logistically easier to observe at
sea level, and astronomers' brains work better at 2 a.m. if they're not
starved of oxygen at 13,500 feet.

But it turned out that Subaru had a staff shortage, and wasn't able to
field two of its own people to be on the summit, at the telescope
itself, for our run. That's a problem, because working alone overnight
in such a remote place, amid such massive equipment, is not only lonely
but dangerous, and observatory rules require at least two people at the
telescope at night. So we astronomers (myself, Dave Tholen from the
University of Hawaii, and Dave Trilling from Northern Arizona
University, plus our assigned Subaru support astronomer Miki Ishii) had
to be at the summit too for our two-night run in early July. This was
good news as far as I was concerned - I didn't mind braving the altitude
and the remoteness if it meant being able to recapture some of the
romance of the old way of connecting with the universe, up there on the
mountaintop.

So, on June 30, after the long flight from Denver to Kona, I left behind
the coconut palms of the Hawaiian coast and drove 9,000 feet up the
mountain to the observer's dormitory. The dormitory, Hale Pohaku
(Hawaiian for "stone house"), is perched near a tree line on the flanks
for Mauna Kea in a scrubby forest of native mamane trees, with a
stunning view of the vast bulk of the volcano Mauna Loa to the south.
Hale Pohaku used to be my home away from home, but I hadn't been there
for eight years, so it was great to be back and slip into the familiar
old routines, and see familiar faces. Joining us at the dormitory was a
film crew from the New Horizons team at the Johns Hopkins Applied
Physics Lab, who were filming a piece about our observing run that I
hope you'll soon be able to watch at this site.

After a night and a day of acclimatization, adjusting our bodies to the
thin air, we climbed into 4WD vehicles and made the half-hour drive to
the summit as sunset approached. It is always an amazing transition
from the relative domesticity of Hale Pohaku and its mamane trees to the
vast, alien, apparently lifeless landscape of the summit and its giant
telescopes. This was the first time at Subaru for some in our group, so
Josh Williams, the telescope operator, gave us a quick tour of the
darkened, cathedral-like space of the dome, almost filled by the huge
bulk of the telescope with its 8-meter diameter mirror. We also made
quick trip around the catwalk outside the dome, to admire the fabulous
view, before returning to the warmth and comfort of the control room,
where we were to spend the night.

After the sightseeing, it was down to business. We made some
calibration observations of the evening sky, and then had about an hour
to wait until the part of the sky where we knew our KBOs were hiding
rose high enough for us to look at it. We had a quick look at a couple
of near-Earth asteroids (NEOs) while we were waiting, to check their
locations in order improve their orbits, and to get a feel for how to
use the telescope and its giant camera. Josh and Miki were amazingly
efficient at getting us pointed in the right direction and properly
focused. The images came in, a sparse scattering of stars against a
black background, and Dave Tholen, copying the images to his laptop, was
able to find one of his favorite NEOs, Apophis, in no time.

Then we finally turned our sights to the KBO search fields, in the heart
of the Milky Way. On the monitors, the blackness of space was suddenly
replaced with a blaze of thousands of stars. We knew there was no way we
were going to pick out our KBOs, Apophis-like, in real time, among all
those Milky Way stars. Our job was just to patiently work through our
pre-determined pattern of telescope pointings (a 3-by-4 mosaic of
adjacent fields), keeping a close eye on the focus to make sure that the
data were of the highest possible quality, and being ready to repeat
fields if the quality was bad due to clouds or poor seeing. We visited
each field three times during the night so we'd be able to use the
motion of the KBOs to separate them from the background stars.

It was a great night - everything went smoothly, the images looked
fabulous, and no fields needed to be repeated. The lack of excitement
made it hard to stay awake as the small hours dragged on. Finally, our
part of the Milky Way began to set in the west, and we had a short time
to pick up a couple more NEOs for Dave Tholen before heading down the
mountain for some sleep.

But then something went wrong. A very peculiar-looking image, with
curved star trails, appeared on the monitor - the camera was obviously
no longer rotating to keep up with the rotation of the heavens. Error
messages that Josh had never seen before started streaming onto the
console, and nothing with the camera was working anymore. Though it was
5a.m., Josh called down to Hilo for backup, and spent an hour on the
phone in fruitless troubleshooting, while the rest of us, unable to
help, dozed fitfully in corners of the control room. Finally he gave
up, the folks in Hilo promised to send a team up to the summit to take a
look, and we all drove down to Hale Pohaku in the morning light for some
much-needed sleep.

But I didn't sleep well that morning, and tried unsuccessfully for
another nap after lunch, worried that I wouldn't be functional for
another long night. Finally I gave up trying and checked my e-mail, only
to learn that I didn't need to worry about working through the coming
night. The problem we'd encountered that morning was serious, serious
enough to eventually make the Hawaii papers
<http://www.staradvertiser.com/news/breaking/125794833.html>. A coolant
hose at the top end of the telescope had broken, and large amounts of
the coolant, a glycol/water mixture, had leaked onto the camera, the
primary mirror and other parts of the telescope. There was no way the
telescope would be back in action that night. (In fact it took three
weeks before Subaru was up and running again.)

Fortunately we'd planned our observations carefully, and had covered the
highest-priority fields, where our KBOs were most likely to be found, on
the first night. So we got maybe 70% of what we came for. While most
telescope and instrument problems aren't this serious, they are an
expected part of the job, an occupational hazard like clouds. So when
we flew back to the mainland, just in time for the July 4 celebrations,
with our laptop hard disks full of fresh data that might just include a
target KBO for New Horizons, we were well satisfied.

Soon, we'll be posting those data on Ice Hunters
<http://www.icehunters.org/>- please join us there if you want to help
us find those KBOs!
Received on Fri 05 Aug 2011 05:12:57 PM PDT