How to Count to One

Generally speaking, if you want to study science, you should study the language of science, which is math. Why is it then, that when astronomers are faced with a kindergarten-level math problem like counting the observatories on Mauna Kea, they can?t agree on the answer? The reason, as it turns out, is that there?s a lot more than math involved.

Let?s start with the most common answer to the question, which is 12. Here is that count:

1.University of Hawaii (UH)
2.NASA Infrared Telescope Facility
3.Canada-France-Hawaii Telescope
4.United Kingdom Infrared Telescope
5.W. M. Keck Observatory
6.Subaru Telescope
7.Gemini Telescope
8.Caltech Submillimeter Array
9.James Clerk Maxwell Telescope
10.Smithsonian Submillimeter Array
11.Very Long Baseline Array (VLBA)
12.Thirty Meter Telescope (TMT)

But wait a minute. That last one, TMT, hasn?t even been built. No worries. You can count the University of Hawaii?s two telescope facilities separately, since they are run from different campuses. You still get 12. Right?

How many observatories are there on Mauna Kea? The honest answer is 12, or 13, eight or even one. Why so many answers? Because there is a lot more than math involved. 

Well, sort of. But now the question has changed so that now we?re trying to count telescopes on Mauna Kea. The answer to that question can range from 13 to as few as 8. Here?s the long count:

1.0.6-meter UH Telescope
2.2.2-meter UH Telescope
3.NASA Infrared Telescope
4.Canada-France-Hawaii Telescope
5.United Kingdom Infrared Telescope
6.Keck I Telescope
7.Keck II Telescope
8.Subaru Telescope
9.Gemini Telescope
10.Caltech Submillimeter Array
11.James Clerk Maxwell Telescope
12.Smithsonian Submillimeter Array
13.Very Long Baseline Array

If you are counting just telescopes near the summit of Mauna Kea, the last on this list (VLBA) can be dropped, bringing the number to 12 again.

But now the very practical matter of how you define a telescope crops up. If a ?telescope? is something that acts as a unit to observe objects in space, then the number of telescopes on Mauna Kea shrinks. For instance, most nights Keck Observatory has two telescopes that work independently from each other. But on some nights they work together as the equivalent of a single telescope 85 meters wide. Subtract one telescope from the total near the summit of Mauna Kea on those nights.

Or take an ongoing project called the ?OHANA (Optical Hawaiian Array for Nano-radian Astronomy). Its aim is to combine five Mauna Kea telescopes with optical fibers to create an 800-meter telescope. ?OHANA has been a collaboration led from Paris involving Canada-France-Hawaii Telescope (CFHT), Gemini, Subaru and Keck.

?We published a 2006 paper in the journal Science for the first demonstration of this technique using fibers between the two Kecks,? said astronomer Julien Woillez of Keck Observatory. ?The next step is a CFHT and Gemini connection.? Combining both Kecks, CFHT and Gemini would make one telescope out of four, dropping 12 to nine. Add Subaru to the mix and it makes one out of five, which brings to total, at those times they work together, to just eight telescopes. How low can this number go?

The number can, in fact, drop to one. The idea was expressed earlier this week in Austin, Texas, by astronomers at the meeting of the American Astronomical Society. In a session on Hawaiian astronomy Scott Fisher and Rose Tseng co-authored a talk entitled, ?The Future of Astronomy Research at the Maunakea [sic] Observatories.? Their abstract contains a line that puts it nicely:

?Above the clouds on the summits of the Big Island of Hawai?i, the Maunakea Observatories (MKO) ?stand as the world?s largest astronomical observatory, with telescopes operated by astronomers from eleven countries?.? (emphasis added)

The idea is already borne out in many ways. There is a lot of collaboration and cross-fertilization among the observatories. There are staff members and directors who work for one observatory, then another. Information is also freely shared among the observatories, as well as with the rest of the world.

?In astronomy, unlike in the corporate world, we are much more open to sharing and cooperation,? said Keck Observatory?s Observing Support Manager, Bob Goodrich. ?Our product is knowledge about the Universe, and when we learn something we tell the rest of the world, including our scientific ?competition?.?

Scientists, for their part, often use Mauna Kea Observatories as if they are one.

?In some cases scientists will use multiple Mauna Kea telescopes to produce a scientific result,? said Peter Wizinowich, Keck Observatory?s Optical Systems Manager. ?This is probably most true of the UH folks since they have access to all of the Mauna Kea telescopes. Also, Gemini, Keck and Subaru swap a limited number of science nights each semester to allow their communities to get access to unique capabilities.

Technological knowledge is also shared.

?If we know something about how to fix someone else?s telescope or other equipment, we are happy to share it,? said Goodrich. ?The observatories demonstrated this after the 2006 earthquake. In spite of the difficulties each individual observatory suffered, they all offered help to each other in recovering as quickly as possible.?

Take as another example Laser Guide Star Adaptive Optics, developed to allow telescopes to cancel out the distortions to starlight caused by Earth?s atmosphere. That breakthrough sparked a lot of cooperative efforts. As Keck, Gemini and Subaru observatories adapted the technology to their telescopes, laser use policies were jointly developed in the late 1990s by a Mauna Kea working group. Laser use issues continue to be addressed by the Mauna Kea Laser Operations Group.

Another collaborative offshoot is the transponder-based aircraft detection project led by Keck engineer Paul Stomski which is aimed at automating the process that shuts off lasers if an airplane flies over the Mauna Kea summit. Gemini, Subaru and Keck are all contributing to the success of this project.

Observatories also help by lending fresh eyes on to check on each other?s work.

?We frequently participate in the design reviews for each others Adaptive Optics systems,? said Wizinowich.

So you can say 13 observatories, or you can debate 12, nine or eight telescopes. But everybody can agree that there is only one Mauna Kea on this planet, and it?s the mountain that makes all the great science possible.