While man has expressed interest in the question
of extraterrestrial life for a very long time, the beginning of the modern SETI age can be
attributed to 2 Cornell physicists in the year 1959. Physicists Giuseppi Cocconi and
Philip Morrison recognized that radio waves can be used to communicate between stars.
Radio waves are special because like any other
type of electromagnetic radiation, they travel at the speed of light. But unlike other
types of electromagnetic radiation, radio waves are not as easily absorbed or scattered,
making it ideal for communicating over long distances.
Meanwhile, a young astronomer, Frank Drake, had
found the same conclusion by himself. In early 1960, he set up an experiment, codenamed
Project Ozma, to listen with a radio antenna for radio waves that might be of
extraterrestrial origin. He aimed his antenna at stars that are similar to our sun, since
those kind of stars are the most likely to have planets and thus, most likely to have
life.
Even though Project Ozma didn't detect any sign
of extraterrestrial intelligence, it piqued the curiosity of others, mostly the Russians.
In the 60's, the Soviet Union took over SETI, using new, daring ways to search the sky.
Instead of aiming at a certain star or cluster of stars, they used antennas with a very
large field of view, scanning vast portions of the sky at a time. The problem with this
strategy is that antennas that have big fields of view are less sensitive than the
directional antennas. Therefore, any extraterrestrial civilizations the Soviets hoped to
detect would have to be extremely technologically advanced in terms of radio
communications.
Eventually, the Americans realized the potential
for SETI research, so they recommenced observations. During the 1970's, many radio
astronomers performed SETI researches of their own, some of which are still being carried
out, to this day. In the late 1970's, NASA's Ames Research Center and the Jet Propulsion
Laboratory (JPL) started planning on a large series of SETI projects. Ames would use a
directional antenna to target sun-like stars, while JPL would scan the whole sky for
signals using a large-field antenna. In 1988, NASA Headquarters finally approved the
strategy after several years of preliminary design. The program finally started in 1992,
but after a year, Congress cut funding.
Without government support, it seemed unlikely
that any SETI projects will be carried out, to the dismay of researchers and interested
members of the public. However, a group of determined scientists have founded the SETI
institute, to continue projects where NASA left off, operating on private funding.
The latest project the SETI institute is
planning is the part of the NASA SETI program called the Targeted Search. This will target
the regions around 1000 sun-like stars, using the worlds largest antennas. This project
will be called Project Phoenix.
Recently, a new way of conducting SETI research
has been recognized. It is called OSETI, or Optical SETI. This involves lasers rather than
radio waves. Learn about it more at the Columbus Optical
SETI Observatory.
Arecibo
observatory, Puerto Rico. These words may not mean much to the general public, but to the
radio astronomer, it is an awesome source of information and a great contribution to SETI
research. This is because the Arecibo radio telescope is the biggest and most sensitive
radio antenna on earth. It has a main reflector dish of 305 meters.
 In 1974, the Arecibo Observatory was also to be the originator
of the most powerful broadcast deliberately transmitted from earth. We were no longer just
listening, because we had made ourselves visible to alien SETI programs. Actually, we
still won't be visible for a while, since the message was sent to the star cluster M13,
21,000 light years away.
The message was a
graphic consisting of the Arecibo telescope, DNA, the Solar System, a stick figure of a
human, and some biochemicals of life as we know it. Although the chances of a reply to
this message are very slim, it did get us thinking about the difficulties of
communicating across such a long distance.
The newest SETI effort, Project Phoenix, is
actually a continuation of a segment of an earlier NASA project that was discontinued due
to inadequate funding. The segment is known as the targeted search.
For the targeted search, astronomers will
inspect the regions around 1000 nearby sun-like stars. Observations commenced in 1995,
using the Parkes 210 ft radio telescope in Australia. This is the largest antenna in the
southern hemisphere. Many interesting signals showed up, but they all proved to be false
alarms.
In September 1996, the project shifted to the
northern skies, using the National Radio Astronomy Observatory's 140 ft telescope in West
Virginia. For 19 months the crew checked the skies, but also with similar results.
With still-high spirits, the team started to
observe in the Arecibo observatory in Puerto Rico, and they still are to this day.
So far, there has been no alien signals
detected, but who knows, maybe that signal will show up tomorrow. |
HISTORY & PROJECT PHOENIX