By Alexei Pace, NEOShield-2 Agent in Malta
A public event was held in Malta in the run up to Asteroid Day on 30 June 2017. The event was held at a recently restored seventeenth-century farmhouse at Buskett Woodlands in Siġġiewi (Malta).
The event was well-attended by members of the Astronomical Society of Malta as well as space enthusiasts as well as several foreigners who attended to learn more about the threat of an impact to the Earth from Near-Earth Asteroids (NEOs).
Some of those attending were skeptical at the thought of an asteroid hitting the Earth, thinking that this was only the subject matter of science fiction films. However they quickly changed their opinion once the opening video showing a collection of actual footage of the Chelyabinsk fireball was shown. This event has raised a lot of awareness since it happened so recently and it was captured and shared widely online on the social media.
My presentation commenced with a brief overview of how the solar system was formed from a large protoplanetary disk/s, explaining the roles of collisions in the early solar system as necessary for the formation of planets (collisional accretion) whilst in the late stages it causes collisional disruption. Asteroids and comets are the small bodies of the solar system, remnants and left over blocks from its formation.
Since these small bodies are the building blocks of the solar system, by studying asteroids one can even obtain a good insight of the constituents of the planets.
The Main Belt of the asteroids was then explained as well as the location of NEOs. Those attending were shown images of asteroids shot by amateur astronomers, appearing as points of light identical to the stars. Blinking of the images and stacking is used to track their motion and identify their nature. Imagery from space probes nowadays helps to reveal the true nature of asteroid surfaces and geology.
The first asteroid, Ceres, was discovered by Giuseppe Piazzi in Palermo on 1 January 1801. Piazzi is of significance in Malta since he taught mathematics there between 1770 and 1773.
A plot of asteroid impacts was shown to contain a lot of large impacts, much more than one could imagine. The 2002 Eastern Mediterranean Event is of significance as it happened so close to Malta. Luckily the object disintegrated over the sea and there was no ground impact. Other events described were the Tunguska one, as well as the one in the Yucatan peninsula (65 million years ago), the Barringer crater in Arizona and Shoemaker-Levy 9 impacting Jupiter – the first collision observed in real time on another planet. Nowadays amateur astronomers have managed to observe impacts on Jupiter in real time through their telescopes whilst imaging the giant planet.
The most important point to be borne out is that NEOs impact the Earth every day so it is not a question “if” a NEO will hit the Earth, but rather “when” it will hit and “how big” the impact will be.
The final part of the talk was on projects like NEOShield-2, pioneering science and technology for NEO impact prevention. A brief description of methods like kinetic impact, blast deflection, gravity traction, combined methods, and civil defence procedures was given.
Finally those attending could listen to another brief talk on astronomy as well as observe the skies using telescopes set up on the roof of the building.
The NEOShield-2 team is very glad to have Alexei on board and very proud of his effort and commitment to the cause. We are looking forward to future events in Malta.