[meteorite-list] Asteroids and Comets

[E.P. Grondine]

Uhh, Ron, 

I'm nearly too damn worn out to comment on this, but I'm not dead yet, so here goes. That's asteroids and comets, not just asteroids. Comets, like the one that killed about 95% of the people living in North America around 10,900 BCE. 

Comets, like Comet Schwassmann Wachmann 3, due back in our vicinity in 2022.

E.P. Grondine
Man and Impact in the Americas


http://www.congrex.nl/09c04/

1st IAA Planetary Defense Conference:
Protecting Earth from Asteroids

27 - 30 April 2009

Granada, Spain

The International Academy of Astronautics will hold its first conference on protecting our planet from impacts by asteroids and comets the week of 
April 27, 2009 in Granada, Spain. The 1st IAA Planetary Defense Conference: Protecting Earth from Asteroids, co-sponsored by the European Space Agency, is the follow-on to two previous planetary defense conferences held in 2004 in Los Angeles and 2007 in Washington, D.C. Details on the 2004 and 2007 conferences are at www.planetarydefense.info

The 2009 meeting will gather worldwide experts on detecting and tracking 
objects that might be hazardous to our planet together with those who work 
on detailed characterisation of these objects, those working on deflecting 
a threatening object should one be detected and those with an interest in 
the nature of impact disasters as well as covering political, legal and 
policy issues that must be considered as part of an overall mitigation 
strategy.

A particular focus of the conference will be the foreseen encounter with 
Apophis, a 300-meter asteroid that is predicted to pass within 40,000 km 
of Earth in 2029 and has a current probability of impacting our planet 
in 2036 of 1 in 45000.

The conference will also be aimed at promoting multidisciplinary work on 
the subject in the years to come. Special emphasis will be given to 
involving students and young researchers from diffent fields, who could 
find on this topic -a better understanding on NEO and the risk they could 
involve- a point of encounter.

At present, there are about 900 asteroids and comets that are designated 
Potentially Hazardous Objects (PHOs), objects that could eventually 
threaten Earth. Ground-based observations are increasing this number by 
more than 600 per year. Experts believe that there could be as many as 
20,000 PHO objects larger than 140 meters.

The most recent significant impact occurred in Siberia, Russia, in 1908 
when an object estimated to be between 30 and 50 meters in diameter 
entered the atmosphere and exploded. The blast levelled and ignited over 
2000 square kilometres of forest.

Researchers have discovered evidence that a larger object exploded over 
Canada 18,900 years ago and that this event caused massive fires in 
North America that caused a 10-degree drop in the average temperature 
in the Northern Hemisphere for 1000 years.

Asteroids and comets are among our closest neighbours, they form part of 
our nearest environment in the Solar System. However we still have a 
great deal to learn about them. We have now some of the technologies 
that might be needed to prevent these objects from hitting the Earth, 
but what would actually be required to be sure a threatening object 
can be tackled? And will we see it coming? The conference will help 
answer these questions.


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