Астероид размером 18 метров пролетит вплотную с Землей в понедельник

Даже если и не пролетит мимо, и даже если диаметр 20 метров, – то в основном сотрётся и сгорит в атмосфере.

Дело в том, что «астероидами» по классификации называют объекты диаметром более 50 метров.

А если меньше – то это называется «метеорное тело», которое практически полностью сгорает в атмосфере.

Moreman,
А если не пролетит мимо..
Н-да...Тунгуска, вот,не пролетела...
Узнать бы скорость,массу,плотность-можно было бы (на случай,если ..."не пролетит"), получить "выход" ....  ( юморю..)

А если не пролетит мимо...

Don Yeomans & Paul Chodas 

NASA/JPL Near-Earth Object Program Office

June 23, 2011

Trajectory of 2011 MD projected onto the Earth's orbital plane. Note from this viewing angle, the asteroid passes underneath the Earth.

Trajectory of 2011 MD from the general direction of the Sun.

Near-Earth asteroid 2011 MD will pass only 12,000 kilometers (7,500 miles) above the Earth's surface on Monday June 27 at about 9:30 EDT. The asteroid was discovered by the LINEAR near-Earth object discovery team observing from Socorro, New Mexico. The diagram on the left shows the trajectory of 2011 MD projected onto the Earth's orbital plane over a four-day interval. The diagram on the left gives another view from the general direction of the Sun that indicates that 2011 MD will reach its closest Earth approach point in extreme southern latitudes (in fact over the southern Atlantic Ocean).

This small asteroid, only 5-20 meters in diameter, is in a very Earth-like orbit about the Sun, but an orbital analysis indicates there is no chance it will actually strike Earth on Monday. The incoming trajectory leg passes several thousand kilometers outside the geosynchronous ring of satellites and the outgoing leg passes well inside the ring. One would expect an object of this size to come this close to Earth about every 6 years on average. For a brief time, it will be bright enough to be seen even with a modest-sized telescope.

http://neo.jpl.nasa.gov/news/news172.html