Spotlight

From the Vatican to Outer Space

David Galligan

The field of planetary science has come alive in recent years. Some key developments have served to keep it in the spotlight, none more so perhaps than the evidence in a Martian meteorite of possible past life on Mars. Interest surrounding Comets Hale-Bopp and Hyakutake has also kept the attention of both the general public as well as the scientific community on this exciting area.

My research involves studying meteoroid orbital dynamics using data obtained from the AMOR radar system run by the Physics and Astronomy Department at the University of Canterbury. Meteoroids are dust originating from comets and asteroids. The AMOR system measures the solar system orbits of individual meteoroids. Over several years it has collected a vast dataset --- the number of orbits catalogued from AMOR greatly surpasses the cumulative numbers from all previous radar surveys overseas.

Data obtained from AMOR have already shown significant results. Last year a paper published in Nature by a team, including my supervisor Professor W.J. Baggaley, convincingly settled a debate which had been going on for a number of years concerning the existence of interstellar dust. AMOR observations showed that there existed a plausible population of meteoroids of interstellar origin. Data from the Ulysses spacecraft served to confirm this.

Earlier this year I had the honour of being invited to attend the 6th Vatican Observatory Summer School in Observational Astronomy and Astrophysics. The theme was "Observations and Theoretical Understanding of Comets, Asteroids and Meteorites". This was particularly relevant to me, considering my research interests.

The school is held biennially in Castel Gandolfo, a town about 25 kilometres from Rome, Italy. This ancient town is set in magnificent scenery, atop a volcanic mountain and overlooking Lake Albano. It is particularly famous as the summer residence of the Pope. It was in his Summer Palace that the month-long school took place. Our hosts were the Vatican Observatory (the Specola Vaticana) who brought together 25 upper-level tertiary students from 21 different countries, of which I was the only one from Australia and New Zealand. The Observatory provided many trips to places of historical and astronomical interest and were very generous in their financial support. Their hospitality for the month was magnificent.

The Vatican Observatory has two physical locations: one at the University of Arizona, US, and one in the Summer Palace in Castel Gandolfo itself. A Zeiss visual telescope and a double astrograph sit in domes on the roof of the Papal Palace. In the nearby Papal Gardens (Villa Barberini) domes housing the "Carte du Ciel" astrograph and Schmidt telescope are also located. The Castel Gandolfo sites are rarely used for "serious" scientific research these days due to the adverse light conditions; most observational research is now carried out in Arizona. However their instruments are still of excellent quality and are more easily accessible than others of their calibre.

Each weekday morning invited international experts shared their knowledge and skills with us in topics related to the school's theme. These talks added up to give a summary of the field. This is very useful to my research --- for example a knowledge of cometary dynamics is necessary in order to understand the dynamics of the meteoroids they have released.

Later each day students talked about their research and in the evenings presentations were given by visiting speakers on general astronomical topics. During the afternoons, several projects were available. One in which I participated was a project to survey the densities of some of the meteorites in the large Vatican Observatory meteorite collection. It was an experience to handle so many relics from outer space. While equipment was relatively primitive -- a barometer used appeared to have a museum tag attached -- the majority of the measured densities agreed well with expectations. So much for big budget science!

A highlight of the trip was a private reception with Pope John Paul II. We travelled to the Vatican and were given special entry to the Vatican museums. From there we entered the adjoining Sistine Chapel and then on into a series of two beautifully painted waiting chambers. We then entered the meeting room and when all were seated in the meeting room, the Pope entered. He read a speech praising so many different nationalities for working together as opposed to against one another. He then personally greeted each of the invitees managing a few words in each of the students native tongues. When he met me he showed his obvious recognition of New Zealand's location "...very far, very far...".

David Galligan is a PhD student studying meteoroid stream dynamics in the University of Canterbury's Physics and Astronomy Department.