Astronomy Chapter 8 - 8.5

The Moon is heavily cratered, but the Earth which "lives next door" is NOT. Why?

the active geology and weather on Earth destroy traces of impacts over millions of years

Which of the following is NOT evidence that objects from space collide with the Earth?

the crater at the top of the Mount St. Helens volcano

In 1980, scientists suggested that the great mass extinction of 65 million years ago (which ended the reign of dinosaurs) may have been caused by a large impact from space. What discovery gives a big boost to this idea?

the discovery of a buried crater (about 200 km across) near Chicxulub, Mexico

What relatively recent event shows that impacts continue to happen in our solar system even today?

a comet (which broke into more than 20 pieces) hit the planet Jupiter in 1994

Which of these did the June 1908 impact event in Siberia and the 2013 event in the Russian city of Chelyabinsk have in common?

they both exploded high in the atmosphere and produced a shock wave that reached the ground