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Author Topic: What A Crowded Solar System We Live In  (Read 4215 times)

app103

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What A Crowded Solar System We Live In
« on: August 15, 2006, 11:54 AM »
The image below is an up to date map of the solar system displaying the orbits of the terrestrial planets and the estimated position of thousands of known asteroids. This diagram is missing comets, space probes and, of course, the undiscovered asteroids. Even conservative estimates would suggest that for every asteroid on a dangerous Earth-Approaching orbit there are hundreds more which have yet to be discovered. There are over 300 known objects on Earth-crossing orbits, the majority of which are potentially capable of causing death and destruction on a scale unheard of in human history.

The terrestrial planets (Mercury, Venus, Earth and Mars) are shown on the diagram by Cyan or White squares, and their orbits are represented by the blue ellipses around the Sun (the yellow dot at the centre). The Earth is highlighted because of its special importance to us. Small green points mark the location of asteroids which do not approach close to the Earth right now. This does not exclude the possibility that they will do so in the future but generally we can consider the Earth to be safe from these for the near future. Yellow objects (with the exception of the one in the middle which we astronomers call the Sun ;-) are Earth approaching asteroids which are called Amors after the first one discovered. Amors have orbits which come close to the Earth but they don't cross the Earth's orbit. However, their orbits are close enough to the Earth that they could potentially be perturbed by the influence of the planets and begin to cross the Earth's orbit in a short time. There are over 300 known objects on such orbits.

Small section of the full map:


lanux128

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Re: What A Crowded Solar System We Live In
« Reply #1 on: August 15, 2006, 11:48 PM »
i've also read about how plentiful these terrestrial bodies are and what would happen if one of them struck the Earth, in Bill Bryson's superbly written A Short History of Nearly Everything.

bbryson.jpgWhat A Crowded Solar System We Live In

Dell[a]

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Re: What A Crowded Solar System We Live In
« Reply #2 on: August 16, 2006, 11:40 AM »
Im not so worried about anything from space destroying the Earth. It's the people who inhabit the Earth that Im worried about...

 :(

Dell[a]

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Re: What A Crowded Solar System We Live In
« Reply #3 on: August 16, 2006, 11:41 AM »
meaning the people... will destroy it...

Carol Haynes

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Re: What A Crowded Solar System We Live In
« Reply #4 on: August 16, 2006, 12:41 PM »
Apparently they have now made a decision that Pluto is indeed a planet (the definition used in the end was a body which generates sufficient gravity to evolve into a round shape - sounds like me after a good curry night).

The upshot is that there are likely to between 100 and 200 'planets' listed in the Solar System over the next few years. So we definitely live in a crowded place.

See http://news.bbc.co.u...sci/tech/4798205.stm