Asteroid (Page 16)

Asteroids have hit the earth many times, causing major extinctions and leaving tell-tale craters?and it turns out there are gigantic craters on Mars as well. Perhaps they wiped out life there as well?

A huge gash that has been discovered on Mars has long proven is the largest known crater in our solar system?so big, that it reshaped the planet by blasting away much of the planet?s crust in the area where it hit over 4 billion years ago.

In New Scientist, David Shiga reports that this conclusion goes along with “other evidence that numerous large projectiles were careening through the inner solar system at this time, such as the Mars-sized planet that walloped the primordial Earth and formed our Moon, yet left no trace on Earth.”
read more

A century ago, an event in far-off Siberia gave us a wake-up call. That explosive event over remote Tunguska is generally viewed by scientists as a large space rock that pierced through the atmosphere of Siberia, then detonated to flatten some 2,000 square kilometers of trees. Could modern technology stop such an event from happening today?perhaps in a crowded city?
read more

The evidence is on the ocean floor – Asteroid impacts, like the one that did in the dinosaurs, are not as rare as we’d like to think they are. 70% of the earth is covered in water, so most asteroids land in the ocean. A researcher who searched for underwater impact craters and found an ominous number of them?several of them very recent, in geologic terms. And a huge meteorite found in Australia 40 years ago has been reanalyzed and now scientists think it may have brought life, in the form of bacteria, to this planet (Australia DOES have some of the world’s oldest?and most unique?life forms).
read more

Is NASA keeping the danger of a potential impact secret? – A 13-year-old German boy working on a science project recently corrected NASA’s estimates on the chances of an asteroid hitting the earth. He figured out that there is a 1 in 450 chance that the Apophis asteroid will hit us, while NASA claims that the odds are only 1 in 45,000.
read more