Ultimately scientists estimate that an asteroid would have to be about 96 km (60 miles) wide to completely and utterly wipe out life on our planet.

What If an Asteroid Hit Earth? - Science | HowStuffWorks

07‏/01‏/2022 — For an asteroid to wipe out most everything on Earth it would have to be massive. Scientists estimate it would take an asteroid about 7 to 8 ...

How big would an asteroid or comet have to be to end life on Earth?

How big would an asteroid or comet have to be to end life on Earth?

Asteroid of just THIS size can DESTROY Earth! NASA outs Scary ...

20‏/02‏/2022 — How big should an asteroid be to destroy Earth? According to NASA Earth-killer asteroids do not have to be big.

Impact Earth - Killer Asteroids

But that is a much bigger rock than anything thats hit Earth in a very long ... People tend to think that an extinction level asteroid or comet would ...

What would be the environmental effects if the earth collided with a ...

If the comet is 10 kilometers across or larger (that is if the impact carries an energy of more than about 100 million megatons) the resulting global ...

How big would an asteroid have to be to wipe out all life on Earth? - SFGATE

09‏/10‏/2015 — University of Colorado Boulder geoscientist Brian Toon figures one rock about a half a mile wide can do a lot of damage and cause widespread ...

An asteroid impact could wipe out an entire city. Heres NASAs plan

14‏/03‏/2022 — Astronomers consider a near-Earth object a threat if it will come within 4.6 million miles (7.4 million km) of the planet and is at least 460 ...

WATCH How Big Does an Asteroid Need to Be to Wipe Out Manhattan?

31‏/03‏/2016 — ... prospect of an asteroid hitting Earth in a nutshell it would only take a small near-Earth object (NEO) to generate massive destruction ...