Barringer crater, Arizona 49,000 yr old Iron meteorite of size 50 m, mass 300,000 ton Impact velocity 11 km/sec Our Earth is a target, too!
150 known impact sites on Earth Diameters from 50-70 m to 200 km
65 million years ago a huge meteorite of 10 km size hit the Earth
<ul><li>World-wide fires </li></ul><ul><li>1-km-hign tsunamis </li></ul><ul><li>Acid rains and atmospheric pollution </li></ul><ul><li>Darkness and severe winter for many decades </li></ul>¾ of all living species have been killed
Our Moon could have been formed in a giant collision 4.5 billion years ago
The Peekskill meteorite October 9, 1992 12 kg stony meteorite hit the Earth
Atmosphere lets the visible sunlight in, but traps infrared radiation and prevents rapid cooling of the surface at nights
"It will be possible to see cities on Mars, to detect navies in [its] harbors, and the smoke of great manufacturing cities and towns... Is Mars inhabited? There can be little doubt of it ... conditions are all favorable for life, and life, too, of a high order. Is it possible to know this of a certainty? Certainly." Samuel Leland 1895 Seasons on Mars? Channels for irrigation ???
Sorry, no channels – just dry canyons, lava flows and dusty deserts …
The Kuiper Belt – home for short-period comets?? Starting in 1992, astronomers have become aware of a vast population of small bodies orbiting the sun beyond Neptune. There are at least 70,000 "trans-Neptunians" with diameters larger than 100 km in the radial zone extending outwards from the orbit of Neptune (at 30 AU) to 50 AU.