Plans for the Future
What are our future plans? We want our own
telescope. We are tired of trying to share the telescope with others and
getting only bits and pieces of time.
We have signed a memorandum of agreement with the University of
California at Berkeley and we are trying to design and build our own telescope.
We call it the 1HT (one hectare) telescope. It will have 10 4 square meters of
collecting area. It will not be your average radiotelescope: It will be able
simultaneously to do both SETI and regular radioastronomy observations because
of its unique construction.
The 1HT will be the equivalent of a standard
100-meter telescope. With a set of small dishes it is possible to have a large
field of view. Within that large field of view there are many SETI targets at
any one time. If there is enough computing power, it is possible with such a
telescope to form multiple beams on the sky.
The plan is to start with three beams. With the
ability to cover a frequency range of 1 to 3 gigahertz (and looking at each
target three times), it will take 6.3 years to look at about 100,000 targets.
If we were more ambitious and could get more computing power quickly, we could
go up to 12 beams and extend the frequency range up to 10 gigahertz. At this
frequency the search would take about 8 years to compete the 100,000 targets.
In addition to serving the observational needs of SETI, it is
our intention that the 1HT be a prototype for the SKA (square kilometer array)
with a million square meters of collecting area. This is an observational
instrument that the astronomy community, in general, wants to build. By serving
as a prototype, the 1HT can stimulate the work necessary make the SKA a
reality. Building the SKA is also in
SETI’s interest because such an instrument will have a sensitivity a factor of
100 better than the 1HT. With the SKA, signals can be detected that are a
hundred times fainter or are the same strength but 10 times farther away. With
such an instrument, I can increase my target list.
What would we be able to observe with the sensitivity
of a square-kilometer array? We could begin to be able to detect carriers
emanating from the equivalent of a terrestrial television station in the nearby
stars. But, we would still only be able to observe 100,000 stars over 9 years.
I would really like to observe a million stars.
If I could process 10 gigahertz of the spectrum
all at once for my thousand-second observation, then I could get a million
stars observed in a decade. However,
this is really betting on Moore’s law that computing power will continue to
grow exponentially. I think it is a good bet.
We have other plans. In addition to the radio
searches that use traditional technology, we are trying to figure out how to
build an omni-directional sky survey device that can look for weak transient
signals. Actually, we know how to build it. What we cannot do is afford the
computing for it. It would take about as much
computing as we currently have on the whole planet right now. Access to
such computing power will come. This is another bet on Moore's law.
Contributed by: Dr. Jill Tarter and Jim Miller
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