The digital age in which we are living has also revolutionised the
way we do astronomy. The quality and quantity of data that
astronomical telescopes such as the PPARC telescopes on the island
of La Palma are now delivering every night of the year would have
been unbelievable only a decade ago.
The data stream lets astronomers answer fundamental questions (and
formulate new ones) about the evolution of the universe and the
galaxies, stars and planets in it --where we come from, where we
are, and where we are going-- on the widest imaginable scale.
Since the seventies astronomical data taking has progressively
turned digital. Developments in light detection technology over the
last decade have dramatically increased data rates from telescopes.
For example, a single standard digital image from a telescope may
contain a moderate 16 Mbyte. But special cameras are built to image
a wide view of the skies in one shot with image sizes of hundreds of
Mbytes. And with hundred or more images taken every night astronomers
are dealing with many thousands of giga-bytes of data per year coming
out of a single telescope.
To image all of the sky once in only one colour would produce a
stunning 20,000 Gbyte of data, or thousands of times the information
content of the Encyclopedia Britanica. This is required to only take a basic
census of what we see in the sky. To understand the physics of
the objects found astronomers require observations at difference
colours, thus multiplying the amount of information many times.
Such large surveys are currently under way and are fundamental to our
understanding of the universe.
This work never stops as object in the sky may change in brightness,
colour and position. For example, the detection of asteroids that
could threaten our own planet, or finding an exploding star in another
galaxy requires comparison of images from one night to the next.
The large data streams require also special state-of-the-art software
and hardware tools to process and archive data. Only one typical image
of the sky easily reveals thousands of stars and galaxies. With such
wealth of information it is clear that analysis of images can only be
done in an automated fashion. Modern software tools are now capable
of fully automatically producing catalogues of objects in the sky, work
that only a few years ago would have taken many days of hard work.
The large volumes of data collected often have to be reduced to a
one-bit answer to a scientific problem; thousands of giga-bytes
reduced to a simple yes-or-no answer. Therefore extensive tools are
developed to aid scientist to reach their final results as quickly as
possible. The fastest workstations are required for such demanding
tasks. The automatic reduction on one image takes about 10 minutes
of computing time on a modern, fast workstation. This is only just fast
enough to keep up with the incoming datastream from the telescope !
To understand what we see, complex theoretical models are developed
of star formation or galaxy formation, or of the evolution of our
universe. These models require the fastest available super computers
to run and allow accurate comparison with what is observed with
And what holds the future in store for us ?
New detector techniques are being developed in laboratories in
Europe and the US. These detectors will produce data at an even
faster rate and consequently require even faster data storage and
handling equipment in the future. In this way scientific needs help
drive technology developments to improve computing performance.
The further development of fully automatic on-line data reduction
techniques will allow scientists to concentrate more on the
scientific results of the observations and achieve results quickly.
And finally, data archives are growing in importance. Linking the
various astronomical data archives world-wide, involving space-based
and ground-based telescopes, opens a whole new field of data mining
for astronomy by making all data globally available and easily
accessible to all scientists.
In many of these activities the Internet is an important tool which
allows scientists to access and transport data across the world.
The future will see a growing use of the Internet to control and
operate telescopes remotely so that scientists can stay at home
to do their observations. So there will be less reason in the future
for astronomers to travel to remote mountain top observatories such
as the one on La Palma.
Dr. René Rutten