{"id":19442,"date":"2019-10-23T00:43:36","date_gmt":"2019-10-22T16:43:36","guid":{"rendered":"http:\/\/stuif.com\/blog\/?p=19442"},"modified":"2019-10-23T15:24:00","modified_gmt":"2019-10-23T07:24:00","slug":"will-an-asteroid-hit-earth","status":"publish","type":"post","link":"https:\/\/stuif.com\/blog\/?p=19442","title":{"rendered":"Will an asteroid hit Earth?"},"content":{"rendered":"\n

Roughly 66 million years ago the Chicxulub asteroid<\/a> with an estimated diameter of 10 km struck Earth at the Yucatan peninsula in Mexico. It caused an extinction of 75% of all plant and animal species, including the dinosaurs.<\/p>\n\n\n\n

In 1908 the Tunguska meteorite<\/a> exploded above a remote region in Russia, flattening about 2000 km\u00b2 of forest. Ongoing discussion if it was a comet or an asteroid. Estimated size 30-80 m. <\/p>\n\n\n\n

On 15 February 2013 an asteroid, size approximately 20 m, exploded at an altitude of ~ 30 km above the Chelyabinsk<\/a> district in Russia. The shockwave caused substantial damage, many people were injured by broken glass.<\/p>\n\n\n\n

And last few weeks there has been “alarming” news in the media about several “space rocks” threatening to collide with Earth and cause havoc. Foremost in this was the British tabloid Daily Express. Here are a few of its headlines (click on the image to see the corresponding article)<\/p>\n\n\n\n

7 September: <\/p>\n\n\n\n

Asteroid shock: NASA warns of \u2018100 percent\u2019 chance of asteroid impact<\/strong><\/p>\n\n\n\n

\"\"<\/a><\/figure><\/div>\n\n\n\n

27 September: <\/p>\n\n\n\n

Asteroid alert: NASA tracks three space rocks heading past Earth at once \u2013 Will they hit?<\/strong><\/p>\n\n\n\n

\"\"<\/a><\/figure><\/div>\n\n\n\n

2 October:<\/p>\n\n\n\n

Asteroid warning: NASA panic as four killer space rocks avoid horror impact with Earth<\/strong><\/p>\n\n\n\n

\"\"<\/a><\/figure><\/div>\n\n\n\n

NASA panics, warning of a \u2018100 percent\u2019 chance of asteroid impact? Hm, time for a post about asteroids and their danger for Earth \ud83d\ude09<\/p>\n\n\n\n

Asteroids are “small” rocky objects, billions of them, orbiting the Sun, most of them in the (main) Asteroid Belt, between the orbits of Mars and Jupiter. Small is relative, more than 150 million are larger than 100 meter and the largest asteroid, Ceres<\/a>, has a diameter of 945 km! Notice the units, used in the picture below. One AU (Astronomical Unit) equals 150 million km, the average distance between Earth and Sun. This unit is often used for distances in the Solar System. For example, Mars orbits at a distance of ~ 1.5 AU around the Sun and the main Asteroid Belt is located between around 2.2 and 3.2 AU.<\/p>\n\n\n\n