Philips Atlas of the Universe

EXPLORING THE UNIVERSE

are not very good, and the site was selected only because

there are no really favourable locations in the old USSR.

Against this, the mountain observatories are spec-

tacular by any standards. The loftiest of all is the summit

of Mauna Kea, the extinct volcano in Hawaii, at well over

4000 metres (13,800 feet). At this height one’s lungs take

in only 39 per cent of the normal amount of oxygen, and

care is essential; nobody actually sleeps at the summit,

and after a night’s observing the astronomers drive down

to the ‘halfway house’, Hale Pohaku, where the air is

much denser. There are now many telescopes on Mauna

Kea, and others are planned. Almost equally awe-inspir-

ing is the top of the Roque de los Muchachos (the Rock of

the Boys), at La Palma in the Canary Islands. The altitude

is 2332 metres (7648 feet), and it is here that we find

the largest British telescope, the 4.2-metre (165-inch)

William Herschel reflector. The ‘Rock’ is truly interna-

tional; La Palma is a Spanish island, but there are observ-

atories not only from Britain but also from Scandinavia,

Germany, Italy and other countries. Another superb site is

the Atacama Desert of Northern Chile, where there are

four major observatories: La Silla (run by the European

Southern Observatory), Cerro Tololo and Las Campanas

(run by the United States), and the new observatory for

the VLT or Very Large Telescope, at Cerro Paranal in

the northern Atacama. The VLT has four 8.2-metre

(323-inch) mirrors working together; the mirrors are

named Antu, Kueyen, Yepun and Melipal. They can also

be used separately.

A modern observatory has to be almost a city in itself,

with laboratories, engineering and electronic workshops,

living quarters, kitchens and much else. Yet today there

is a new development. Telescopes can be operated by

remote control, so that the astronomer need not be in the

observatory at all – or even in the same continent. For

example, it is quite practicable to sit in a control room

in Cambridge and operate a telescope thousands of kilo-

metres away in Chile or Hawaii.

Observatories are now world-wide. There is even an

observatory at the South Pole, where viewing conditions

are excellent even though the climate is somewhat daunt-

ing. The AST/RO (Antarctic Submillimetre Telescope

and Remote Observatory) is in constant use; AST/RO has

an aperture of 67 inches (1.7 metres).

Kitt Peak, Arizona. Kitt

Peak is the US national

research facility for ground-

based optical astronomy. Its

largest optical telescope,

seen at top right, is the

Mayall reflector, with a

3.81-m (150-inch) mirror;

the altitude is 2064 m

(6770 feet). The triangular

building in the foreground is

the McMath–Pierce Solar

Facility, the world’s largest

solar telescope.

Antarctic Submillimetre

Telescope and Remote

Observatory AST/RO, at the

South Pole, where conditions

for this kind of research are

exceptionally good.

▲Dome of the Palomar

5.08-m (200-inch) reflector.

The Hale reflector was

brought into action in 1948,

and was for many years in

a class of its own. Though

it is no longer the world’s

largest, it maintains its

position in the forefront of

research, and is now used

with electronic equipment,

so that it is actually far more

effective than it was when

first completed.

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