Tumbling Stone (english)

About the Sirente lake: the first italian impact crater?

About one year ago, TS announced an important scientific hypothesis: a small circular lake in the Prati del Sirente plain, in the heart of the Abruzzo mountains, was proposed to be the first impact crater ever discovered in Italy. In an interesting article (see TS issue n.18, "The discovery of the Sirente crater field"), Jens Ormö, Angelo Pio Rossi, and Goro Komatsu described the years of research that followed the discovery and the scientific proofs they found. This year, a second article by a different group of researchers appeared on Meteoritics & Planetary Science, announcing that the lake should not be the result of a meteoritic impact. TS asked to the authors of this new research to explain how they came to this new conclusion.
One thing is for sure: we will keep on hearing about the Sirente lake.

An anthropogenic origin for the Sirente crater
by Fabio Speranza - Istituto Nazionale di Geofisica e Vulcanologia

In our paper ["An anthropogenic origin of the 'Sirente crater', Abruzzi, Italy", by F. Speranza, L. Sagnotti and P. Rochette] published on Meteoritics & Planetary Science, we report the results and the conclusion of a specific study on the morphological and geological characters of the Sirente plain (...). We conclude that the lake from the Sirente plain is not the result of a meteoritic impact, but rather is the well preserved relict of an efficient hydraulic work created by man, taking advantage of a natural setting favourable to the accumulation and retain of water...read the full article.

The history of NEOs' science TS presents the third and last part of a series of articles about the history of science by Andrea Carusi. You can read here the previous parts: part I "Astronomy at the time of Copernicus", published in issue n.21, and part II, "The Solution of the Planetary Problem", published in issue n. 22. Part 3 : The solution of the Problem of Motion by Andrea Carusi - President of SGF Galileo Galilei (1564-1642) is unanimously considered the most important physical scientist of the XVIIth century, and indeed the founder of modern science. His role in the controversy on the Copernican hypothesis and in its final victory was decisive, but his major contribution was not of an astronomical nature. Galileo revolutionised the way of understanding nature and its phenomena, as well as the methods of investigation and analysis... (read the full article)
	2004 FH: don't panic! by Ettore Perozzi - Telespazio When going through one of the many astronomical calendars available on the internet, side by side with classical celestial phenomena such as eclipses and occultations, an ever increasing number of close encounters of NEOs with the Earth is found. But - don't panic! - this does not mean that an increasing number of NEOs are actually passing close to our planet: that would surely be a source of deep concern... read the full article The mysteries of the Asteroid rotation day by Alessandro Rossi - ISTI Why there are no asteroids with diameter larger than about 100 m rotating faster than about 11 revolutions per day (corresponding to a period of about 2.2 hours)? Why do we observe so many binaries among Near Earth Asteroids? How is a binary asteroid created? (...) These are some of the questions we tried to answer during the 'Asteroid Rotation Day' held at the ISTI-CNR in Pisa, on April 26, 2004... read the full article

Editor: Nanni Riccobono
Assistant Editor, web master and graphics: Livia Giacomini (lagia@tiscalinet.it)

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