If you ever clean the gutters of your roof, note the following: The dirt you throw may be from outer space.
The new book "Cosmic Impact: Understanding the Threat to the Earth of Asteroids and Comets" by Andrew May (Icon Books) provides an overview of the potential dangers we may one day encounter with near-Earth objects ( Near Earth Objects, NEOs), and on a smaller scale finds that objects fall from space to the earth is a daily occurrence.
"On an average day, about 100 tons of meteorite dust fall on the planet," writes May. "One of the best places to find it is on non-porous surfaces such as city rooftops and gutters. , , The mud in your gutter will almost certainly contain some particles that come from outer space. "
Dust particles from space do not expose the planet and its inhabitants to deadly danger. Asteroids like the ones that made the dinosaurs die out are the most worrisome.
The 124-mile Chicxulub Crater near the Mexican Yucatan Peninsula was forged 66 million years ago when an object 69 miles in diameter entered space from space. The resulting fire and dust, the latter covering the Earth's atmosphere and shielding the sun, eventually killed the dinosaurs.
If we met a similar object today, the result would be similar.
"The devastation would be so much greater than anything that occurs in human experience that it is hard to imagine," writes May. "If the impact were in the ocean, the water would boil. If it were on land, large areas would be devastated by firestorms. The dust, whirled up by a Chicxulub-sized impact, would prevent sunlight from reaching the Earth's surface for months – maybe even years. "
The good news, however, is that the likelihood is great that such an object in our lives on Earth will hit near zero.
The Torino scale takes into account the size of the NEOs and the likelihood that they will hit Earth over the next hundred years to estimate the potential danger on a scale of 1 to 10.
At present the coming century looks so safe.
"There is currently no known object with a Torino rating of up to 1," writes May. "Everything we know is either too small to do any harm, or it's unlikely to be in the next collided with the earth for a hundred years. "
However, this was not always the case. Only in 2004, an object was discovered that had a worrying Torino number of 4, indicating a decent contact opportunity, which would lead to an innumerable destruction.