The star stakes

How can Europe retain its ranking for excellence in astronomy? This question – together with the resulting strategies – is posed by the Astronet study group in its recent report ‘A Science Vision for European Astronomy’.

The small telescopes of the ESO Observatory, in La Silla (Chile), beneath the Milky Way. © ESO The small telescopes of the ESO Observatory, in La Silla (Chile), beneath the Milky Way. © ESO

Europe today is a world leader in astronomy. This success is built on the pooling of previously scattered EU resources, including the founding of the European Southern Observatory (ESO) for ground-based astronomy and the European Space Agency (ESA) for space astronomy. Supported by the Commission, the Astronet group is seeking to harness all of Europe’s space exploration strengths in a joint effort across the complete astronomy chain. This ranges from subjects of research in astrophysics – from the solar system to the universe – to the many current or planned “ground/space” observation resources, as well as selecting from the vast range of possible observations (from light to gravitational waves).

Given the technical and financial resources required, realising the desire to push back the frontiers of our knowledge in astronomy can no longer be left to isolated teams. It requires an international mobilisation of scientists, as is already the case in particle physics with Cern for example. “It is now accepted that future major investments in astronomy will only be made in the framework of cooperation between the Union countries. The way in which this trend develops will depend on political and economic events,” stresses Johannes Andersen, chairman of the Astronet Board and director of the Nordic Optical Telescope on the island of La Palma in the Canaries (ES).

The results of pure science

When it is suggested that astronomy can appear to be a particularly costly science that is not very ‘profitable’, Johannes Andersen’s reply is that such a view is too simplistic. “Our research is not costly when compared with fields such as high energy physics. Astronomy also brings practical benefits – in predicting solar eruptions for example – and employs very high tech companies in meeting its equipment needs. When it enables us to realise that just 5% of the universe is made up of ordinary matter, its work can be seen as making a vital contribution to fundamental physics. It is also one of the sciences that, right from the start, has had a unique ability to fascinate.”

Questions for the next 20 years

Astronet has recently identified “the key astronomical questions to which the answers can be provided over the next 20 years by combining observations, simulations, experiments, interpretations and theories”. For example, the extreme universe and the observation of black holes – the monsters with a gravitational pull so strong that not even light can escape them. Or gamma ray bursts, the most luminous event in the universe. Also on the programme is the nature of dark energy or dark matter, two entities that make up more than 95 % of the content of the universe. Yet nobody really knows what they are.

Another subject for exploration is the formation and development of galaxies. How did the first concentrations of matter appear that served as the ‘grains’ of galaxies? How did they then evolve to form, among other things, the Milky Way? The same applies to the formation of the stars and planets. At the heart of stars, the heavy elements (carbon, oxygen, iron, etc.) were formed – and are still being formed – that constitute the basis of planets such as Earth. Although 253 exoplanets have already been discovered over the past decade, encountering a planetary system with conditions favourable to the development of life still seems very much a long shot. Understanding the formation of these objects is also a way of understanding the path that leads to life.

Last but not least is the need to further expand our knowledge of the solar system. As the Earth’s ‘backyard’, its exploration is vital to comprehending how our planet was created and has evolved.

The importance of computing

Mobilising European astronomy in the way proposed to decision-makers – both European and national – requires the resources to match the stakes. The Astronet report stresses that “several needs seem to be common to most themes […] and investments in these fields are therefore priorities for astronomy.”

One of the most important needs is for a computing infrastructure able to respond to such questions. The theories developed by astronomers are increasingly complex, taking into account a growing number of physical phenomena and their mutual interactions. To test these theories and make predictions, extremely complex numerical simulations must be carried out. Marenostrum is a good example of such research, bringing together Spanish, French, German, American and Israeli researchers in simulating the formation of galaxies. Using 800 processors simultaneously, its calculation time would be more than 126 years if only one computer were used.

These simulations generate staggering amounts of data, running into dozens of terabytes (1012). These must then be compared with observations. This again requires major computing muscle as multiplying all these observations for all the wavelengths of the electromagnetic spectrum means a second proliferation of data. One could imagine that it would be sufficient to store them, but how to use such a vast library without any classification system? How to find a way around such a labyrinth? Vast computing capacities are therefore necessary for the storage, analysis and comparison of data from many sources and in many formats.

Reinventing chemistry

A first step in this direction was accomplished with the creation of the European Virtual Observatory. Its mission is to permit electronic – thus virtual – access to all available observational data and to make available to scientists the best possible tools for analysing them.

Finally, Astronet stresses the need for an efficient astrophysics laboratory. As instruments become more sensitive, so more chemicals in solid or gaseous states are being detected, including in the interstellar environment. When synthesised in the laboratory for the purposes of detailed study, these assume particular importance if, for example, we want to understand the processes at work in forming certain amino acids, the building blocks of life that are found in space.

What will be next? “We are going to describe the tools needed to realise the projects featured in the Science Vision report and see how they can be developed within a reasonable timeframe,” explains Johannes Andersen. “In cooperation with funding agencies to ensure that everything will be financially realistic, the scientific community will project the budgetary aspects and necessary human resources. We are also drawing up a review of all the programmes and procedures for granting funds by the various European countries, with the idea of proposing better coordination and cooperation between their observatories.”

Stéphane Fay


To find out more

  • Astronet
    21 partners – 13 countries (FR - DE - IT - ES - NL - UKLT - SE - GR - HU - EE - AT - SK),
    two non-EU countries (Switzerland, Israel)
  • A Science Vision for European Astronomy