Write NO MORE THAN TWO WORDS for each answer.

UNDERSTAND AN ASTEROID

A source of worry 

• There can be a collision between asteroids and the Earth. 

• Asteroids can contact some 31 [31] and cause devastation with unexpected consequences. 

Sizes and locations 

• Asteroids come in various sizes. 

• Large asteroids closely resemble 32 [32]

• Small asteroids are 33 [33] of the bigger ones. 

• The asteroids that orbit in the space normally remain in the belt between 34 [34] and Mars.

Categorization  

• There are typically 3 types: M-Type, C-Type and the S-Type. 

• The names are given in relation to the richness of 35 [35], stone and the composition of metallic materials. 

Observation  

• Most asteroids can be seen using a 36 [36]

• They can be observed in certain conditions depending on the sky's level of darkness and how good the 37 [37] is. 

The Pioneering Effect 

• 1891: technology started to be used to detect asteroids. 

• 1800s-1900s: people thought discovering asteroids was not worth their time. 

• Since late 1900s-2000s: 

- The number of people who were interested in locating and 38 [38] asteroids grew significantly. 

- The three groups of asteroids near the Earth-Atens, the Apollo's and the Amors are 39  [39] and checked regularly using new technology. 

- A greater 40  [40] is aroused with regard to the possibility of the Earth being struck by the asteroids nearby.