Detail Cantuman Kembali

XML

Planetary Defense : catastrophic health insurance for planet earth


Concern exists among an increasing number of scientists throughout the world regarding the possibility of a catastrophic event caused by an impact of a large Earth-crossing object (ECO) on the Earth-Moon System (EMS), be it an asteroid or comet. Such events, although rare for large objects (greater than 1 km diameter), are not unprecedented. Indeed, the great upheaval and resulting ice age that marked the extinction of the dinosaurs is thought to have been caused by the impact of a 10 km diameter asteroid. Such an event is thought to occur approximately every millennia. In 1908 a stony asteroid of approximately 50 meters diameter exploded in the air above the Tunguska River in Siberia, producing an equivalent yield of 15-30 megatons (mt) of TNT, leveling over 2000 square miles of dense forest. Such an event is thought to occur approximately every century.
John M. Urias - Personal Name
SR 368.012 JOH m
9781249829621
368.012
Text
English
CPSIA
2012
USA
LOADING LIST...
LOADING LIST...