Page 62 - BBC History The Story of Science & Technology - 2017 UK

Heaven & Earth / Astronomy

A BRIEF HISTORY

Heather Couper explains how our understanding

1 Time and place Even more impressive is the

Midsummer sunrise at Stonehenge
is so iconic that the place swarms 300 BC monument at Chankillo,
with New Agers and latter-day Peru, where a line of 13 towers
Druids watching the Sun climb marks points at which the Sun
Druids above the Heel Stone. However, rises throughout the year. Yet
celebrate the latest research suggests the preliterate civilisations didn’t just
the Druids’ ancient predecessors keep time by the heavens: the
summer
solstice at watched the Sun set from the Polynesians used the stars to
Stone- Heel Stone on midwinter’s day. navigate from Hawaii to
henge, Either way, Stonehenge marks the New Zealand – a distance of over
1983 extremes of the calendar. 7,000km – out of sight of land!

astronomer 5
An engraving A matter of some gravity Andreas
showing French While Cambridge University was closed due to Cellarius’s
c17th-
Cassini III observing the plague in 1665, Isaac Newton returned home century
Halley’s Comet in to Woolsthorpe Manor, Lincolnshire, where he illustration
Paris in 1759 formulated the law of gravity – which stipulates of the
how every body in the universe attracts every Copernican
other. But he didn’t publish it until persuaded to by system,
Edmond Halley, who used Newton’s law to calculate placing the
that comets seen in 1531, 1607 and 1682 were the Sun at the
same visitor. And it was this law that led Halley centre of
to predict the return in 1758 of the comet that the universe
bears his name.

6 New worlds

On 13 March 1781, a German amateur
astronomer living in Bath doubled King George III, but the name Uranus
was internationally accepted. Over the
the size of the solar system. decades, astronomers found that
William Herschel (pictured) Uranus was being pulled by the
discovered a “curious gravity of a more distant planet,
either nebulous star or leading to the discovery of
comet” – which turned out Neptune in 1846. Pluto,
to be a planet twice as far discovered in 1930, was at first
from the Sun as Saturn. called a planet but, uniquely in
Herschel wanted to name history, its status as a planet
it Georgium Sidus, after was revoked in 2006.
REX FEATURES/BRIDGEMAN/GETTY/SCIENCE PHOTO LIBRARY 10 There’s only one place in the universe where we exist include the ice-covered oceans on Jupiter’s

The quest for life

moon, Europa, and Saturn’s satellites Enceladus
know life certainly exists, and that is, of course,
and cloud-wreathed Titan.
Earth. However, the next shattering discovery in
astronomy is likely to be life on another world.
There’s plenty of scope for life out there –
Mars is probably home to
after all, as of today, there are more than 4,000
planets circling other stars. And in 2007,
micro-organisms, according to
Heather Couper is a
the Labelled Release experiment
scientists of the SETI programme (the Search for
broadcaster and the author,
Extraterrestrial Intelligence) began operating a vast
on the Viking landers that Nasa
with Nigel Henbest, of
that may detect radio broadcasts from aliens that
Other possible habitats in the
(Philips, 2017)
solar system where life could
have evolved from bacteria to intelligence.
62 Philips Stargazing 2018 sent to the Red Planet in 1976. new receiver in California, the Allen Telescope Array,
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