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The tangible movable heritage of astronomy: instruments and artefacts

The distinction between fixed property and movable objects is important from the juridical and heritage perspective, but has no real significance for astronomers. For an instrument, what is important is its scientific function and its technical performance. The distinction between a fixed instrument and a movable instrument is only a question of factors such as dimension, technology and materials, precision of observation, stability, and the necessity of moving the instrument for observation.

A more pertinent distinction is that between a ‘collective instrument’, shared by a professional group of astronomers in some context, and an individual instrument. The notion of the personal use of astronomical instruments—for example, not only for scientific research but also for navigation, leisure purposes, etc.; or not only for astronomical observations but also for decoration, collection, etc—could easily be linked with the broader application and/or social use of astronomy, but only more rarely with a decisive improvement in observational techniques and/or theoretical progress that might mark it out as having exceptional universal value.

A collection of rare or unique movable instruments authentically associated with the history of an observatory is obviously a major part of the latter’s heritage value. Thus, assessing an observatory must therefore involve making a detailed study of the functionality and of the construction and use of each instrument, exactly as would be necessary for a movable part of a technological monument or for a ‘machine-tool’ in industrial heritage. For the scientist, this is the real core of the material value of the observatory, perhaps more than walls and architecture; these could in a really poor state while the site remains of major importance in the history of astronomy.

Concerning collections of movable instruments, the UNESCO initiative ‘Movable Heritage and Museums’ may be relevant to some aspects of this type of heritage.

Some issues

Edwin Aldrin about to set foot on the moon. Photog

Edwin Aldrin about to set foot on the moon. Photograph by Neil Armstrong. Credit: NASA (public domain)

Assessing the value of tangible movable heritage can raise a variety of issues. For example, in the case of Palaeolithic mobile art on movable artefacts—objects such as the Ishango Bone from the Democratic Republic of the Congo that may provide some of the earliest insights into human perceptions and uses of the skies:

  • Does their existence strengthen the value of their place of discovery, even if they are now removed from it in museum collections?
  • Should we focus at all on the place of discovery, when what is important from the astronomical heritage point of view is the object itself?
  • Is the authenticity of the object more to do with the reliability of the archaeological context it came from than with its own ‘genuineness’ (e.g. lack of damage/restoration)?

Jumping from one end of the timescale to the other, space heritage throws the issue of ‘fixed’ versus ‘movable’ heritage into sharp focus. A ‘fixed’ location on the moon, such as Neil Armstrong’s landing site or first footprint, is a moving point relative to any location on the earth; while a geostationary satellite which, to some degree of approximation, is stationary relative to any location on the earth, would not seriously be considered a ‘fixed’ object. Clearly, relativity of movement seems a poor criterion for heritage evaluation in these cases (albeit an excellent illustration for a major concept of modern physics). The only reasonable conclusion is that the dichotomy between ‘fixed’ and ‘movable’ makes little sense as a classificatory criterion in astronomical heritage in particular, or in science or technology heritage in general.

The contents of this page are based upon text in the ICOMOS-IAU Thematic Study no. 1 (2010). Original text © Clive Ruggles, Michel Cotte and the contributing authors.