On this page, we are showing the interactive 3D models which reproduce a few objects kept in the Museum of INAF Astronomical Observatory of Palermo. The technique used to reproduce these objects is photogrammetry: an image-capturing method that, starting from simple pictures taken by a digital camera allows you to create a tridimensional model.

This simple process fits the logic of image-based modelling, namely 3D modelling based upon images and rendering methods starting from 2D pictures. First of all, place the object at the centre of a room (if it is large), or in a small photo shoot, and take at least two shots of the objects from different points of view. We should also take into account the lights, which should be placed around the object without creating shadows.

Once we have taken as many shots as possible of the object from various angles, we can upload the photos on 3DF Zephyr Lite, a widely used software for photogrammetry. The tool puts together all the shots realized and produces the 3D model.

The Errico Melendez’ Folding Camera

Realized in London between the end of the 19th century and the start of the 20th century, it is made of brass, mahogany, glass and leather. It was realized for photographers and travellers and is ideal for scientific expeditions.  It was probably used by the astronomer Temistocle Zona (1848-1910) during his expedition to Sfax, in Tunisia, in order to observe the total solar eclipse of 1905.

Mars Globe dated late 19th century

This model was acquired by the Observatory around 1878, as Giovanni Schiaparelli presented to the scientific community his findings on the observation of the alleged channels of Mars. In the model, we can see these channels well represented.

 

Pendulum Clock (Cumming & Grant), 1790

This clock was bought in London by Giuseppe Piazzi, the first director of the Observatory. In Palermo, it was placed in the circular room which hosted the Ramsden Circle, i.e. the instrument with which Ceres was discovered, and regulated on sidereal time.  At the start of 1903, it was cleaned up and placed in the central room of the Museum.

 

Bust of Giuseppe Piazzi (1746 – 1826)

The first director of the Observatory of Palermo, Piazzi is known for having compiled two important stellar catalogues and for commissioning the Ramsden Circle, an azimuth instrument he needed to discover Ceres in 1801, the first asteroid ever observed, reclassified as a dwarf planet starting from 2006.

 

Terrestrial Globe by Rigobert Bonne, 18th century

It is quite rare and was bought by Jérôme Lalande on behalf of Giuseppe Piazzi and sent to Palermo.
The globe is made of paper-mâché covered with plaster, on which the printed paper is applied. This is a special kind of paper called “papier du nom de Jésus”, divided into twelve sections from -70° and +70° degrees of latitude, and two polar caps. The meridian is made of brass and the support is in walnut wood.

 

Bust of Angelo Secchi (1818-1878)

Angelo Secchi, a Jesuit astronomer, is considered the founder of astronomical spectroscopy. He was the director of the Observatory of the Collegio Romano in Rome and was the first to classify the stars in spectral classes.

 

Delamarche’s Armillary Sphere

This object represents a small globe with two small metal arms, which support the small disks of the Sun and of the Moon. Ti goes back to the half of the 19th century. The materials used are brass, cardboard and iron.

 

Porcasi’s Planetarium

From the archive sources, we know that it was built by Giuseppe Porcasi, a mechanic at the Royal Observatory of Palermo, around 1810-1820, on a drawing by Giuseppe Piazzi. The central golden sphere represents the Sun, whereas the cardboard disks represent the planets which were known at the time, such as Mercury and Venus. We may notice an open circle, made of wood and paper, which stands for the Earth’s orbit, to which a second, the smaller open circle is linked, which stands for the Moon’s orbit. There follows Mars and four small planets: Vesta, Ceres, Pallas and Juno, as well as Jupiter, Saturn (depicted on the disk with the ring) and finally Uranus (which appears with the name of Herschel, who discovered it, according to the French usage at the time). Two vertical external circles represent equinoxes and solstices, and a horizontal circle represents the celestial Equator.

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The 3D models were realized by Salvatore Speziale (INAF Astronomical Observatory of Palermo).