QUESTIONS 75-30
You are advised to spend about 20 minute* on Questions 15-30 which refer to
Reading
Passage 2 below
READING PASSAGE 2
From a gianl antenna set among the
The search's prospects of success are founded
undulating sheep paddocks of rural Australia,
on a formula known as the Drake equation,
one of the great voyages of discovery has
developed by SETI Institute founder Dr Frank
begun — the Search for Extraterrestrial
Drake This says that the number of
Intelligence, or SETI What the international
civilizations in
the Milky Way galaxy whose
Project Phoenix uncovers is likely to be so
radio emissions are detectable depends on
utterly different from our kind, so vastly more
sophisticated, as to defy imagining
• The rate of formation of life-supporting stars
• The proportion of those stars with planets
The SETI institute, a California!! research
• The number of earthlike planets per solar
foundation, managed to raise $A16 million to
system
fund Project Phoenix, which is using the
• The fraction of those on which life develops
Australia Telescope at Parkes in New South
• The fraction of those where intelligence
Wales for its search To make its discovery, the
develops
telescope needs
an extra-special hearing aid, a
• The fraction of those where technology
device which resembles an old-fashioned ear-
develops, and
trumpet Chilled to minus 260°C and crammed
• The lifetimes over which such civilizations
with electronics, this feed-horn is the most
can release detectable signals into space
sensitive built Responsibility for its
construction fell to the Commonwealth
To eliminate the dozens of interference events
Scientific and Industrial Research Organisation
which occur daily,
the new search uses
radio-engineer Dr Kel Wellington, another true
something called a FUDD — a follow-up
believer since childhood in the existence of
detection device There is one at Pnrkes itself
intelligence somewhere in the cosmos
and another on a CS1RO antenna at Mopra, 200
km away If a promising signal is detected by
Project Phoenix is a methodical search Of the
the mam antenna it is cross-checked on the
40,000 million stars in our galaxy of similar age FUDDs If they fail to see it, then it is probably
and character to our sun, 1000 have been
local radio interference — perhaps
a farmer on
selected which lie within 120 light years of
his mobile phone If they all see it, loud and
Earth On a galactic scale, that is a bit like
clear, the excitement begins
searching a one-metre circle of grass on a 100
metre football oval
At that point, says Dr Bobbie Vaile,
astrophysicist at University of Western Sydney,
The Parkes antenna zeroes on each star in turn,
Macarthur, the first step is to check, recheck
checking the 200 visible only from the southern and check again If the signal is still there and
hemisphere The feedhprn listens in on radio
is consistent over time the
next step is to call
channels between 1700"and 3000 megahertz,
up colleagues on radiotelescopes around the
the most
efficient communication frequencies
world and ask them to home in on the same
It is here that the awesome power of modern
star and frequency If they see it too, and the
technology comes into play the computers
signal is narrow and unnatural-looking, it
scan each of 28 million channels in blocks of
could come from another civilization
searching among the clutter for the elusive
pattern of a carrier signal that underlies all
At
this point, she says, the Australian I'nme
complex radio or TV transmissions
Minister and the US President would be
notified and <) public press conference
many years, maybe lifetimes — and we have
convened 'It certainly won't be kept quiet It
been sending radio messages out into the
will be a discovery lor all humanity.'
cosmos for nearly a century. A visit on either
And it will be a decision for humanity whether
side is virtually out of the question- to send a
or not to respond The Project Phoenix team
ship to the closest star. Alpha Centauri, four-
will only listen and learn — they will not
and-a-half
light years distant, would consume
transmit any replies. In any event, Vaile points
energy equal to humanity's total use for 20
out, even to exchange messages would take
years
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