ARTICLES
The European Space Agency (ESA) and GAIA
By George Pinniger
Since the Soviet Union launched Sputnik#1 into space in 1956
there have been numerous rockets launched carrying their
precious cargo into space. Astronomers and astronomy-aware
teachers of physics will recognise names such as the Hubble
Space Telescope (HST), Kepler, COBE, Chandra, possibly the
ESA’s Hipparcos, Rosetta, Herschel, and even the James Webb
Telescope (which has not yet been launched) since it is anticipated
to be able to ‘see’ right across the known Universe. However, in
2013 the ESA launched one special astronomical observatory of
its own named ‘Gaia’ in 2013. Its resolution is extraordinary; while
Hipparcos mapped 120 000 stars over 4 years, and its auxiliary
telescope, Tycho, mapped one million more with less accuracy,
Gaia has already mapped 1.7 billion with far greater precision.
That was mere practice – now to business! Gaia’s present task
is to plot a 3-D map of our Milky Way Galaxy, in the process
revealing its composition, formation and evolution. Its resolution
is so accurate, and the time it takes to capture images so short
that Gaia will provide unprecedented positional and radial
velocity measurements with the accuracies needed to produce a
stereoscopic and kinematic census of about a billion stars in our
galaxy and throughout the Local Group! In 2017 the Solar System was visited very briefly by ‘Oumuamua’,
a long, narrow interstellar object, thought by some to be proof of
intelligent life elsewhere in the galaxy. On 25th September, 2018,
using data from ESA’s Gaia stellar surveyor, astronomers have
identified four possible stars from which it originated.
The ESA's Gaia space laboratory The interstellar visitor named 'Oumuamua'
2nd October, 2018, a team of astronomers using the latest set
of data from the Gaia mission seeking high-velocity stars leaving
the Milky Way were surprised to discover other stars speeding
inwards instead – perhaps from other galaxies!
Much more will be heard about Gaia because of what it is now
achieving. However, my advice to those who are interested to
know more about astronomy and cosmology based on Gaia’s
discoveries so far, there is a really superb 28-minute presentation
(in English) by Dr Jackie Faherty, explaining so much, including
showing the proper motion of stars in our galaxy with stunning
videos!
See https://youtu.be/LOJ1XmbSKhM
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SCIENCE EDUCATIONAL NEWS VOL 67 NO 4