Please helpWhat additional info does the sidebar provide?

The sidebar tells us what Earth scientists are actually doing about the risk of an asteroid impact.

Explanation:

The main part of the page discusses how frequently the moon is hit by rocks;  how most rocks are too small to make it past Earth's atmosphere; how the rocks that do make it all the way to Earth's surface are usually pretty small and don't hit anything important; how screwed we would be if a massive rock – like an asteroid – made it to Earth's surface.

The sidebar says that scientists are understandably worried enough about these asteroids – they "feel the danger is to great to ignore" – so they're keeping a lookout for asteroids that might be on a collision course with Earth.

what novel are you talking about?

no : /