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4.5 BILLION years ago
A Solar Nebula condences to form everything but the Sun, including comets, asteroids, planets and moons. -
3.8 BILLION years ago
The inner planets (Mercury, Venus, Earth Mars) and their moons get bombarded by comets left over from planet building. These impacts are great enough to keep the planets molten. -
65 MILLION years ago
The dinosaurs and other creatures die out because a comet 300kms long hits Earth creating the crater called Chixculub, which is now known as Mexico's Yucatan Peninsula. -
50,000 years ago
A fifty meter wide comet hits Arozona and creats the most well preserved crater, which is 4kms long. -
613BC
The earliest record of any comet was thought to be the first sighting of the Halley's Comet -
350BC
Aristotle says that comets are in the upper atmosphere. This view lasts two-thousand years. -
312AD
Roman Emperor Costantine thought he saw a cross in the sky, so he converted his faith to christian. Some believe this was a comet, while others believe it was a meteroite impact. -
1066
A wicked appearence of Halley's Comet is seen and then recorded on the Bayeux Tapestry before the Norman conquest of england. a piece of cloth that recorded the events before the conquest -
1577
Tycho Brahe measures where a great comet was and compared it with other sightings, and proved it was about four times further away then the moon. -
1705
Edmond Halley proves that comets orbit the sun by being the first to accuratly predict when a comet would reappear. -
1908
An airburst over Siberia is heard thousands of miles away. This ear-ringing phenomena was later thought to be a comet that exploded in the outer layers of our atmosphere. -
1950
Fred Lawrence Whipple creates a model of cometary nuclei, which still prevails. Jan Van Oort proposes that comets come from a shell of billions thousands of times further from the sun than Earth. It's now known as the Oort region. -
1960
Geologist Eugene Shoemaker proves that aArozona was made by an impact. -
1979
Luis Alverez and mates are the first to publish a paper linking the extintion of the dinosaurs to an impact. -
1980
The spacewatch survey led by Tom Gehrels begins at Arizona. This is the first systematic search for any large object that might impact Earth. -
1990
The Chixculub crater is now proven to be the cause of the extinction of the Dinosaurs. -
1992
A US panel proposes a spaceguard program which will keep an eye on comets or metorites that are larger than one kilometer long. -
1993
Comet Shoemaker-levy 9 discovered. Resembling a line of pearls it was most likely to be the first known comet shattered by Jupiters intence gravitational pull. In 1994 the pieces crash into Jupiter for a couple of hours. -
1995
The Near -Earth Asteroid Tracking (NEAT) program begins at Hawaii. The rate of near asteroids increases over ten times the previous amount. -
1996
The first asteroid that's orbit that could possibly strike Earth. -
1999
The Tornio Scale is published by astronomer Rick Binzel. 0 = no chance 10 = almost certain global devastation. -
2001
1950 DA is the most likely to hit Earth. It may hit Earth in 2880. -
2004
NASA's space craft flies by a comet, collecting comet dust and taking up-close photographs. The asteroid called Apophis is rated 4 on the Torino scale - the highest ever recorded. The threat has been reduced due to improved orbital caculations. The first ever object purposly sent to impact a comet was sent on the 4th of july, and was NASA's deep impact space craft called Tempel 1. A method is proposed to move comets by using gravity. -
2005
The US congress tells NASA to look for comets 150m wide or more, instead of over one kilometer. -
2006
NASA's stardust spacecraft landed with examples of comet dust.
