34 replies to this topic

[Sky Scanner]

freetoroam, on 17 February 2013 - 09:21 PM, said:

A meteorite is simply an object that has entered another bodies atmosphere (in this case planet Earth) and survived travelling through the atmosphere to impact the ground. An asteroid never impacts another bodies atmosphere, and has no atmosphere itself. An asteroid can range in size from small to very large, and even have their own moon/s.

Edit - to simplify the difference, they are both basically the same thing, both originating from space, they are separated only by location, an asteroid stays in space, a meteorite is what hits the ground.

Edited by Sky Scanner, 17 February 2013 - 09:31 PM.

[DieChecker]

william joseph, on 16 February 2013 - 07:42 PM, said:

http://news.yahoo.co...-215440387.html

Novel idea

Hasn't this idea been around for years? Aim a laser of some kind and the vaporized materials push the asteroid out of the critical path.

What scares me is the 1.4 Megatons of energy being tossed around. Whoever controls this De-Star4 thing could just as easily turn it on the Earth and fry cities with zero chance of defence.

Myself, I favor sending an ion drive robot satellite to individual asteroids and using those to push the asteroids away.

shrooma, on 17 February 2013 - 12:55 PM, said:

strange, how the meteorite went from being 'a couple of metres' across, to 50ft across. in my book, a couple of metres is six feet, not fifty!
who did the maths on this thing, forrest gump??
a 50ft meteorite would've done more than break a few windows I reckon, and I wonder what kind of TARDIS effect allowed a 50ft object to fit inside a 16ft crater.....?

It likely created a smaller hole because... most of it vaporized 15 miles up.

It also blew out just windows because.... most of it vaporized 15 miles up. 15 miles......

So.... You want every report to be the same, starting immediately after the event and not being changed later to reflect incoming data? No one had any idea how big it was at first, but after people analyzed the energy output and area affected and reviewed how high it was and at what angle it came in at.... All that leads to a better guess on the size... 50 feet in diameter.

[DieChecker]

Sky Scanner, on 17 February 2013 - 09:27 PM, said:

A meteorite is simply an object that has entered another bodies atmosphere (in this case planet Earth) and survived travelling through the atmosphere to impact the ground. An asteroid never impacts another bodies atmosphere, and has no atmosphere itself. An asteroid can range in size from small to very large, and even have their own moon/s.

Edit - to simplify the difference, they are both basically the same thing, both originating from space, they are separated only by location, an asteroid stays in space, a meteorite is what hits the ground.

I thought the difference between an asteroid and a meteoroid is only size. They can be made of the same materials and both can impact other bodies in space. From what I've read, generally an asteroid has to be larger then 10 meters in diameter. Smaller then that and it is a meteoroid. It is a meteor when it hits the atmosphere, and a meteorite if it reaches the ground.

Quote

In 1961, the International Astronomical Union defined a meteoroid as "a solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom". In 1995, Beech and Steel, writing in Quarterly Journal of the Royal Astronomical Society, proposed a new definition where a meteoroid would be between 100 µm and 10 meters across. Following the discovery of asteroids below 10 m in size, Rubin and Grossman refined the Beech and Steel definition of meteoroid to objects between 10 µm and 1 m in diameter. The smallest asteroid (based on absolute magnitude) is 2008 TS₂₆ with an absolute magnitude of 33.2, and an estimated size of 1-meter. Objects smaller than meteoroids are classified as micrometeoroids and cosmic dust. The Minor Planet Center does not use the term "meteoroid".

http://en.wikipedia.org/wiki/Meteoroid
http://en.wikipedia.org/wiki/Asteroid

So, going off Wiki, this 50 foot, 15 meter, rock could be considered a mereoroid, or an  asteroid. Or, perhaps even both.

[Sky Scanner]

DieChecker, on 17 February 2013 - 09:46 PM, said:

I thought the difference between an asteroid and a meteoroid is only size. They can be made of the same materials and both can impact other bodies in space. From what I've read, generally an asteroid has to be larger then 10 meters in diameter. Smaller then that and it is a meteoroid. It is a meteor when it hits the atmosphere, and a meteorite if it reaches the ground.


http://en.wikipedia.org/wiki/Meteoroid
http://en.wikipedia.org/wiki/Asteroid

So, going off Wiki, this 50 foot, 15 meter, rock could be considered a mereoroid, or an  asteroid. Or, perhaps even both.

Well yes and no, really, lol. Size becomes less relevant when compared to composition, yet they are both more or less the same material too....it depends how indepth you want to get about it really, hence just giving a simplified version. This explains it pretty well:

http://www.universet...and-meteorites/

[freetoroam]

Sky Scanner, on 17 February 2013 - 09:27 PM, said:

A meteorite is simply an object that has entered another bodies atmosphere (in this case planet Earth) and survived travelling through the atmosphere to impact the ground. An asteroid never impacts another bodies atmosphere, and has no atmosphere itself. An asteroid can range in size from small to very large, and even have their own moon/s.

Edit - to simplify the difference, they are both basically the same thing, both originating from space, they are separated only by location, an asteroid stays in space, a meteorite is what hits the ground.

Getting this now. So the name changes when it enters Earths orbit. Like a foreigner is only a foreigner once they enter someone elses country.
So if the meteorite never hits the ground and stays in space, it is still an asteroid?

If a piece of rock broke off from an asteroid, is it still classed as an asteroid or is it now a piece of space rock until it hits earths orbit then it becomes a meteorite?

My initial "confusion" was that the meteorite came from an asteroid, i was asking where is that asteroid?  I can understand if it is too far out to even think about, but when the others hit in other parts of the Earth I just thought this too much of a coincidence if they were not related to each other.

Only one asteroid has been spotted and none of these meteorites which have hit Earth come from it....are you seeing my confusion?

[freetoroam]

DieChecker, on 17 February 2013 - 09:46 PM, said:

I thought the difference between an asteroid and a meteoroid is only size. They can be made of the same materials and both can impact other bodies in space. From what I've read, generally an asteroid has to be larger then 10 meters in diameter. Smaller then that and it is a meteoroid. It is a meteor when it hits the atmosphere, and a meteorite if it reaches the ground.


http://en.wikipedia.org/wiki/Meteoroid
http://en.wikipedia.org/wiki/Asteroid

So, going off Wiki, this 50 foot, 15 meter, rock could be considered a mereoroid, or an  asteroid. Or, perhaps even both.

Edited by freetoroam, 17 February 2013 - 09:59 PM.

[shrooma]

freetoroam, on 17 February 2013 - 09:21 PM, said:

when they hit our atmosphere, they're meteors, but when they hit the ground they're meteorites, and the one in russia left a 16ft hole in the ground, so it's DEFINITELY a meteorite!
:-)

[Sky Scanner]

freetoroam, on 17 February 2013 - 09:54 PM, said:

Getting this now. So the name changes when it enters Earths orbit. Like a foreigner is only a foreigner once they enter someone elses country.
So if the meteorite never hits the ground and stays in space, it is still an asteroid?

If a piece of rock broke off from an asteroid, is it still classed as an asteroid or is it now a piece of space rock until it hits earths orbit then it becomes a meteorite?

My initial "confusion" was that the meteorite came from an asteroid, i was asking where is that asteroid?  I can understand if it is too far out to even think about, but when the others hit in other parts of the Earth I just thought this too much of a coincidence if they were not related to each other.

Only one asteroid has been spotted and none of these meteorites which have hit Earth come from it....are you seeing my confusion?

It's not the case that it just has to enter earths atmosphere, on it's travel through the atmosphere it is a meteoroid, and not all meteoroids hit the ground, some skim the atmosphere and shoot off into space again, it's only when it hits the ground that it's a meteorite.

So if a piece of asteroid breaks off in space, it's still an asteroid, unless it enters the atmosphere of another body, then it changes again.

[freetoroam]

"Do you mean asteroid. An object is only a meteorite if it has actually hit the ground."

Thankyou Sky scanner, I understand it now. its the above bit from another thread which originally confused me.

Either way, it still stands that they are not all detectable...at this moment in time.

[equus hemionus]

I suspect our arrogance will doom us before any phisical threat of nature. We seem to keep "all eggs in one basket" rather than putting more effort into survival of our speices. Nature seems to roll dice.

[highdesert50]

Like all sentient beings we wish to live comfortably in as little pain as possible with the understanding that we will not live forever. The looming issue is whether we as a civilization expect to perpetuate. If so, then we certainly need to focus altruistically on a plan to promote the survival of our civilization whether it be from falling debris or other peril. That is an evolutionary step forward. Can we frame our individual lives as selfless rather than selfish entities?

[MedicTJ]

freetoroam, on 17 February 2013 - 06:48 PM, said:

i really would much rather someone spend the money on getting rid of the nuclear weapons which are popping up all over the joint.
Thats where the real danger lies.

Funny really, they were all watching the DA14 and on the other side of the world we were getting bombarded with "small rocks" no one knew they were coming or where they came from.


ps: my school where one them bestest in Sauf London.  

(in regards to bold print) That almost sounds like a message, doesn't it?  The translation would be, "Yes, good job on tracking near-earth-objects.  But guess what?  I can hit you whenever I want to hit you and you can't do anything to stop it."

I am convinced that there's no coincidence here.  If there were, the Russian object would have been a piece of DA14.  But we were made VERY aware that that wasn't even a remote possibility.

[DieChecker]

Rocks like the one that blew up over Russia could be tracked... But to what point?? They clearly are not going to do much more then damage a building or two. No one was reported killed that I know of. I'd much rather the scientists keep looking for the "game ending", Boss Monster asteroids, and let the little ones just take care of themselves.

[WoIverine]

There isn't a shark that's big enough...

[Frank Merton]

This idea of people turning meteors into weapons seems ironic -- back to the age when we throw rocks at each other.

I have no doubt that an early-warning system for stray rocks heading our way will happen.  The technology is there just begging to be used.  Risk management involves multiplying the chance of an occurrence times the severity.  In this case the chance is small but the consequence (things on the order of the obliteration of a city or worse) severe enough that the equations show the need.  (We already have such a system for planet-obliterating type objects -- it doesn't seem any present any near danger).