Would this asteroid hit be different than a meteor hit? Is this going to be like the one that hit Jupiter years ago?

Asteroid could hit Mars in January

LOS ANGELES, California (AP) -- Mars could be in for an asteroid hit. If the asteroid strikes Mars, it will probably hit near the equator close to where the rover Opportunity is exploring.

A newly discovered hunk of space rock has a 1 in 75 chance of slamming into the red planet on January 30, scientists said Thursday.

"These odds are extremely unusual. We frequently work with really long odds when we track ... threatening asteroids," said Steve Chesley, an astronomer with the Near Earth Object Program at NASA's Jet Propulsion Laboratory.

The asteroid, known as 2007 WD5, was discovered in late November and is similar in size to an object that hit remote central Siberia in 1908, unleashing energy equivalent to a 15-megaton nuclear bomb and wiping out 60 million trees.

Scientists tracking the asteroid, currently halfway between Earth and Mars, initially put the odds of impact at 1 in 350 but increased the chances this week. Scientists expect the odds to diminish again early next month after getting new observations of the asteroid's orbit, Chesley said.

"We know that it's going to fly by Mars and most likely going to miss, but there's a possibility of an impact," he said.

If the asteroid does smash into Mars, it will probably hit near the equator close to where the rover Opportunity has been exploring the Martian plains since 2004. The robot is not in danger because it lies outside the impact zone. Speeding at 8 miles a second, a collision would carve a hole the size of the famed Meteor Crater in Arizona.

In 1994, fragments of the comet Shoemaker-Levy 9 smacked into Jupiter, creating a series of overlapping fireballs in space. Astronomers have yet to witness an asteroid impact with another planet.

"Unlike an Earth impact, we're not afraid, but we're excited," Chesley said.

I think that this would be somthing cool to watch but how do we watch it?

[QUOTE=SW fan;1682221]I think that this would be somthing cool to watch but how do we watch it ?

You might get lucky if an impact happens while mars is above the celestial horizon and you have access to a suitable telescope.

cool and what are the chances that this will happen?
Because if thier decent then i think that ill give it a try.

There are a few orbiters already in orbit around Mars, so it would be possible to image the asteroid approach, and perhaps image the crater if it hit.

Is this going to be like the one that hit Jupiter years ago?


Not at all like the COMET that hit Jupiter. This is an ASTEROID to begin with

and they aren't sure it will hit Mars at all. The difference is that asteroids

are solid objects where comets are made of ice.

If it doesn't hit Mars there is a chance it`ll hit The Earth in the 23rd October, 2011.
But it is not too big so hopefully it isn't going to make to much of a impact (if it hits).

Well F*** mars then.

[QUOTE=SW fan;1682238]cool and what are the chances that this will happen?
Because if thier decent then i think that ill give it a try.

I can't give you the odds but an astronomer might be able to do so.
Some of the conditions are:

Mars must be visible from your geographical position.The impact must create a cloud of dust and other particles that will be visible in the telescope you are using You must know the expected time of impact and its predicted position.Your telescope must be large enough to provide sufficient magnification,. A rule of thumb is that magnification must not exceed about 50 times the diameter of the object lens measured in inches. So a 6" telescope cannot provide a useful magnification greater than 300X under good seeing conditions.
Your telescope will need some form as drive because you'll be looking at a moving object

You will probably be able to get more information in an Astronomy magazine or on the internet.
If you can't see it happening in real time, you will certainly find images after the event on the internet.
I am assuming there will be an impact.
I hope this helps

[QUOTE=SW fan;1682221]I think that this would be somthing cool to watch but how do we watch it ?

You might get lucky if an impact happens while mars is above the celestial horizon and you have access to a suitable telescope.

It's always above the horizon from either the Northern or Southern hemisphere of Earth and we have plenty on observatories in both. You can be sure that someone will be watching - perhaps even Hubble or one/more of the current Mars orbiters. It WILL be recorded. News at ten, film at a eleven! :)

...I can't give you the odds but an astronomer might be able to do so....

I think the article said 75:1
How are those odds? Good?

Not at all like the COMET that hit Jupiter. This is an ASTEROID to begin with and they aren't sure it will hit Mars at all. The difference is that asteroids are solid objects where comets are made of ice.

how would it compare to a meteor?

Wow, an asteroid hitting mars, now that would be interesting, better turn on the rovers, they will certainly record the event.

can you imagine if it hit a rover? lol

[QUOTE=Read-Only;1682375][QUOTE=Myles;1682228]

It's always above the horizon from either the Northern or Southern hemisphere of Earth and we have plenty on observatories in both. You can be sure that someone will be watching - perhaps even Hubble or one/more of the current Mars orbiters. It WILL be recorded. News at ten, film at a eleven! :)

You are quite right. Thanks for pointing out my error.

[QUOTE=Orleander;1682378]I think the article said 75:1
How are those odds? Good?

Pretty long. It means that if you wanted to make a bet with me for $1, I would pay you $75 if an impact occurred. Does that help ?

[QUOTE=Orleander;1682378]I think the article said 75:1
How are those odds? Good?

Pretty long. It means that if you wanted to make a bet with me for $1, I would pay you $75 if an impact occurred.Does that help ?

how would it compare to a meteor?


From the size of it, which isn't that large to begin with, it will be like a 15 to

20 kiloton a bomb explosion. A meteor is an asteroid that enters the

atmosphere.

Wow, an asteroid hitting mars, now that would be interesting, better turn on the rovers, they will certainly record the event.

No, the rovers aren't designed to look skyward and it would be pure luck if they happened to be looking at the proper part of the horizon AND not be be blocked by some mountain or other surface feature. Remember - they sit VERY low on the surface! However, there are currently some orbiters that might very well see the impact.

So it would be MUCH more correct to say that there's likely NO chance the rovers would record it.

"If the asteroid hits Mars we'll get a great look at the crater within a few days of impact" - HiRISE principal investigator Alfred S. McEwen of the UA's Lunar and Planetary Laboratory.

Read more (http://uanews.org/node/17415)

The TV told me that the crater will be as big as the one in AZ. And my TV doesn't lie to me.
LOL

It sounds more like a meteor than an asteroid suince I would expect the latter to make a far larger crater, particularly on a planet with only a third of the gravity of Earth.

It sounds more like a meteor than an asteroid suince I would expect the latter to make a far larger crater, particularly on a planet with only a third of the gravity of Earth.

What are you talking about?!?! An asteroid BECOMES a meteor when it enters the atmosphere of a planet! :bugeye:

I refreshed the Astronomy page and noted that a certain point scoring idiot had answered after me on this thread and wondered how you had managed to display your ignorance in a desperate effort to score a point against me. For your (badly needed) education :

http://dictionary.reference.com/browse/meteor

http://dictionary.reference.com/browse/asteroid


It's all down to size. So according to you, let's see, if 560 mile diameter Ceres came too close to the Earth and entered our atmosphere, it would suddenly shrink down to a tiny meteor so we'd have no problem? :D

I refreshed the Astronomy page and noted that a certain point scoring idiot had answered after me on this thread and wondered how you had managed to display your ignorance in a desperate effort to score a point against me. For your (badly needed) education :

http://dictionary.reference.com/browse/meteor

http://dictionary.reference.com/browse/asteroid


It's all down to size. So according to you, let's see, if 560 mile diameter Ceres came too close to the Earth and entered our atmosphere, it would suddenly shrink down to a tiny meteor so we'd have no problem? :D

As usual with the derogatory name-calling AND a lack of basic understanding. I thought you didn't believe in references??? But since you gave those, here's an even better one from a NASA website:

"The size of meteorites varies greatly. Most of them are relatively small. The largest meteorite ever found weighs about 66 short tons (60 metric tons). It fell at Hoba West, a farm near Grootfontein, Namibia. However, much larger bodies, such as asteroids and comets, can also strike the earth and become meteorites.

Meteorites reach the earth's surface because they are the right size to travel through the atmosphere. If they are too small, they will disintegrate in the atmosphere. If they are too large, they may explode before reaching the earth's surface. One such object exploded about 6 miles (10 kilometers) above the Tunguska River in Siberia in 1908, leaving a 20-mile (32-kilometer) area of felled and scorched trees. "

Found at this URL: http://209.85.165.104/search?q=cache:XHmYNDbsT60J:www.nasa.gov/worldbook/meteor_worldbook.html+meteor+%2Bsize&hl=en&ct=clnk&cd=2&gl=us

No, the rovers aren't designed to look skyward and it would be pure luck if they happened to be looking at the proper part of the horizon AND not be be blocked by some mountain or other surface feature. Remember - they sit VERY low on the surface! However, there are currently some orbiters that might very well see the impact.

So it would be MUCH more correct to say that there's likely NO chance the rovers would record it.

you read what I am saying, yet you take no time to interpret it. All I am saying is that the rover could see what conditions are created when a meteor of a large size hits a planet. I said absolutely nothing about the rover's design in looking skyward. You always seem to jump to conclusions about people's thoughts.

you read what I am saying, yet you take no time to interpret it. All I am saying is that the rover could see what conditions are created when a meteor of a large size hits a planet. I said absolutely nothing about the rover's design in looking skyward. You always seem to jump to conclusions about people's thoughts.

No, you are the one who's jumped to conclusions here. I simply mentioned the fact in passing that the rovers aren't designed to look skyward, meaning that they can't see it approaching. But the main thrust of my post still remains as accurate as when I posted it.

Imagine lying on you stomach and propping up on your arms and hands - that's about as high (or a little more) as the rovers can see. And while in that position, how much do you think you could see with mountains and other obstacles in your line of sight? Answer: not very much at all. Perhaps a very distant dust cloud at the most - but even that is debatable.

If the asteroid is on a course for the rover's location? All I am saying is that NASA could see the effects IF the asteroid hits extremely close to the rover. It will likely be destroyed but some data could be analyzed, but my idea remains very unlikely.

If the asteroid is on a course for the rover's location? All I am saying is that NASA could see the effects IF the asteroid hits extremely close to the rover. It will likely be destroyed but some data could be analyzed, but my idea remains very unlikely.

Yes, I would say it HIGHLY unlikely - since we're only talking about two VERY tiny pinpoints on something as big as the entire planet Mars. ;)

Consider this bit of fact. Of all the people on the Earth, there's only been ONE single instance of anyone anywhere having been struck by meteorite. It was a woman in Sylacauga, Al and happened sometime in the late 1950's (or very early 1960's - but I believe the first time period is the correct one.) Think of just how many people there have been here in the last 100 years alone - and she's been the only one. Anyway, that should give you a good idea of the real odds involved.

It sounds more like a meteor than an asteroid suince I would expect the latter to make a far larger crater, particularly on a planet with only a third of the gravity of Earth.


Where do you get your ideas from ? It will be a question of the natue of the terrain, the mass of the meteor and its velocity on impact. The mass of mars will have a small influence on that velocity.You have it the wrong way round. The fact is that the greater the gravitational attraction of a body, the greater the velocity on impact and the greater the size of the crater, given terrain of the same composition and a meteor of the same size and composition.

As you sem interested in these things, why not get an introduictory book on physics and work through it. The concepts and associated equations are quite simple insofar as your present post is concerned. You should know enough in a week or two to understand what I have told you.

It sounds more like a meteor than an asteroid suince I would expect the latter to make a far larger crater, particularly on a planet with only a third of the gravity of Earth.


Where do you get your ideas from ? It will be a question of the natue of the terrain, the mass of the meteor and its velocity on impact. The mass of mars will have a small influence on that velocity.You have it the wrong way round. The fact is that the greater the gravitational of a body, the greater the velocity at impact and the greater the size of the crater, given terrain of the same composition and a meteor of the same size and composition.

As you sem interested in these things, why not get an introduictory book on physics and work through it. The concepts and associated equations are quite simple insofar as your present post is concerned. You should know enough in a week or two to understand what I have told you.

Where do you get your ideas from ? It will be a question of the natue of the terrain, the mass of the meteor and its velocity on impact. The mass of mars will have a small influence on that velocity.You have it the wrong way round. The fact is that the greater the gravitational attraction of a body, the greater the velocity on impact and the greater the size of the crater, given terrain of the same composition and a meteor of the same size and composition.

As you sem interested in these things, why not get an introduictory book on physics and work through it. The concepts and associated equations are quite simple insofar as your present post is concerned. You should know enough in a week or two to understand what I have told you.

Sadly, he will never buy a book. He thinks that they (and all professional scientists) are out to quash new innovative thinking and hold back the real progress of science. :shrug: I dare you to challenge his belief that the Doppler effect isn't correct. ;)

No, you are the one who's jumped to conclusions here. I simply mentioned the fact in passing that the rovers aren't designed to look skyward, meaning that they can't see it approaching. But the main thrust of my post still remains as accurate as when I posted it.

Imagine lying on you stomach and propping up on your arms and hands - that's about as high (or a little more) as the rovers can see. And while in that position, how much do you think you could see with mountains and other obstacles in your line of sight? Answer: not very much at all. Perhaps a very distant dust cloud at the most - but even that is debatable.
Read-Only, the rover's cameras can image the Martian sky. The twin panoramic cameras and twin navigation cameras are mounted on a mast that gives 360 degree rotational motion and 90 degree up and down motion. They often image the sky to assess atmospheric clearity and to look for clouds. Whether either of the rovers would be in a good location to image a meteor trail in the atmosphere or not is not known as of yet, but the rovers are on opposite sides of Mars.

Read-Only, the rover's cameras can image the Martian sky. The twin panoramic cameras and twin navigation cameras are mounted on a mast that gives 360 degree rotational motion and 90 degree up and down motion. They often image the sky to assess atmospheric clearity and to look for clouds. Whether either of the rovers would be in a good location to image a meteor trail in the atmosphere or not is not known as of yet, but the rovers are on opposite sides of Mars.

Thanks for that - I wasn't aware they could be aimed skyward. Learned something new today. :)

Read-Only. NASA let the tea boys fill in such sites as you quoted which is why I don't use them and you do. Try :

Chicxulub, located on Mexico's Yucatan peninsula, eluded detection for decades because it was hidden (and at the same time preserved) beneath a kilometer of younger rocks and sediments. Size isn't the only thing that makes Chicxulub special. Most scientists now agree it's the "smoking gun" -- evidence that a huge asteroid or comet indeed crashed into Earth's surface 65 million years ago causing the extinction of more than 70 percent of the living species on the planet, including the dinosaurs. This idea was first proposed by the father and son team of Luis and Walter Alvarez in 1980.

http://www.jpl.nasa.gov/news/features.cfm?feature=8


Yet the site you used calls that a meteor.

"If a small asteroid or large meteoroid survives its fiery passage through the Earth's atmosphere and lands upon the Earth's surface, it is then called a meteorite."

http://neo.jpl.nasa.gov/faq/#diff

Where do you get your ideas from ? It will be a question of the natue of the terrain, the mass of the meteor and its velocity on impact. The mass of mars will have a small influence on that velocity.You have it the wrong way round. The fact is that the greater the gravitational attraction of a body, the greater the velocity on impact and the greater the size of the crater, given terrain of the same composition and a meteor of the same size and composition.

As you sem interested in these things, why not get an introduictory book on physics and work through it. The concepts and associated equations are quite simple insofar as your present post is concerned. You should know enough in a week or two to understand what I have told you.


No need to get hysterical and jabber wildly. You just have to ask me to explain further. Mars has a third Earth's gravity. That means that it is not so densely packed in the first place with only a third of Earth's gravity pushing down on it so any impact will throw much more material into the air which will drift muchg further with only 1/3 gravity trying to pull it down again. So a much bigger impact site as compared to Earth.

"If a small asteroid or large meteoroid survives its fiery passage through the Earth's atmosphere and lands upon the Earth's surface, it is then called a meteorite."

http://neo.jpl.nasa.gov/faq/#diff


Meteor : The light phenomena which results when a meteoroid enters the Earth's atmosphere and vaporizes; a shooting star.

Meteoroid : A small particle from a comet or asteroid orbiting the Sun.

Meteorite : A meteoroid that survives its passage through the Earth's atmosphere and lands upon the Earth's surface.

An ambiguous site which doesn't even agree with itself. Why do they let teaboys write such things?

It's fucking simple.

Meteoroid and asteroid are names for objects in space. Asteroids are big. Meteoroids are small.
Meteor is the name of the light phenomenon as they enter the atmosphere.
Meteorite is what they're called after they've hit the ground.

Stop being an ass.

@invert_nexus
i just watched the story of "Ignorance" and "Want" from `A Christmas Carol (http://www.cedmagic.com/featured/christmas-carol/1951-xmas-ignorance-want.html)`.

... and what would be the change the object get's captured as a new moon, the changes must be slim but Mars pretty much has proven that the conditions are ideaal for this

@invert_nexus
i just watched the story of "Ignorance" and "Want" from `A Christmas Carol (http://www.cedmagic.com/featured/christmas-carol/1951-xmas-ignorance-want.html)`.

You are confused. I know that story and it never mention meteors, asteroid, meteorites or anything of the kind.

well!
it's about time!
been like waiting forever!

Jesus H Christ!!!
SOMETHING is gonna hit mars. I swear, you guys can find anything to fight about. Instead of talking about the impact it will have on the planet, you want to quibble about what to call the hunk of rock.

I hope when it hits, we get to see evidence of some underground water.

[QUOTE=kaneda;1685209]No need to get hysterical and jabber wildly. You just have to ask me to explain further. Mars has a third Earth's gravity. That means that it is not so densely packed in the first place with only a third of Earth's gravity pushing down on it so any impact will throw much more material into the air which will drift muchg further with only 1/3 gravity trying to pull it down again. So a much bigger impact site as compared to Earth.[/QU

Why do you find it necessary to be so offensive when all I'm trying to do is help you ? What do you mean by " jabber wildly " ?

Now to business:

When one talks about the density of earth or mars, one is talking about mean density. You seem to be unaware of this. The mean density of mars is 3.94gms/cm^3. This compares to a mean density of 5.52 gms/cm^3 for earth

Your mistake is to assume that mars and earth have uniform densities.

So the size of the crater will depend on the nature of the terrain where the impact occurs, as I have already explained.

Finally, may I suggest that if you wish to be taken seriously, you should not use expressione like " gravity pushing down "

I know that story and it never mention meteors, asteroid, meteorites or anything of the kind.

LOL,
Spirit was mentioned.

(It was just my observation that it is a simple case of giving information to those wanting to learn, but it is simpler, according to the second of the Three Spirits, to ignore `ignorance`, as the only way that the `ignorant` can learn is by their own self-will. )
BTW, I believe there is a `ignore feature` on this site for just those occasions. Just click on the offenders avatar and choose the appropriate option...

LOL,
Spirit was mentioned.

(It was just my observation that it is a simple case of giving information to those wanting to learn, but it is simpler, according to the second of the Three Spirits, to ignore `ignorance`, as the only way that the `ignorant` can learn is by their own self-will. )
BTW, I believe there is a `ignore feature` on this site for just those occasions. Just click on the offenders avatar and choose the appropriate option...

I don't know the story; I was pulling your leg. What it says about the ignorant chimes with my own experience. And that brings to mind Alexander Pope:

" A little learning is a dangerous thing "


Merry Christmas

Where do you get your ideas from ? It will be a question of the natue of the terrain, the mass of the meteor and its velocity on impact. The mass of mars will have a small influence on that velocity.You have it the wrong way round. The fact is that the greater the gravitational of a body, the greater the velocity at impact and the greater the size of the crater, given terrain of the same composition and a meteor of the same size and composition.

As you sem interested in these things, why not get an introduictory book on physics and work through it. The concepts and associated equations are quite simple insofar as your present post is concerned. You should know enough in a week or two to understand what I have told you.


Of course, Myles. This is not offensive and I can't think why I thought you were jabbering.

Where did I assume they have the same overall densities? The overall density of a planet has no effect in this sense on an impact on it's surface. It is the density of the material at the impact area which counts. Like for like at the impact area on Mars and Earth, an impact crater on Mars will be far bigger than an impact crater from the same incoming rock at the same speed in both cases.

Obviously I meant the gravity pulling down. A busy cybercafe is not the best place to concentrate, especially when you have kids playing "shoot-em-ups" at full volume.

"A little learning is a dangerous thing "


Everyone starts off with a little learning. It's all in the application of the learning.

Jesus H Christ!!!
SOMETHING is gonna hit mars. I swear, you guys can find anything to fight about. Instead of talking about the impact it will have on the planet, you want to quibble about what to call the hunk of rock.

I hope when it hits, we get to see evidence of some underground water.

A good sized impact on the Earth facing side of Mars in our night time would be more valuable to us than any Mars rover.

invert nexus. I'd call someone an ass when they don't trust the link they give and deliberately misquote from it to back up a wrong statement.

Well gents, as far as impact craters go, the energy of impact is of far more significance than slightly different regional densities or even the difference in the gravitational field of the planet, especially given the relatively comparable nature of the earth and mars.

A given impactor size at a given impact energy will leave about the same sized hole on earth or mars. What will be different is the altitude that the ejecta will reach. Obviously it will go quite a bit higher on mars.

A good sized impact on the Earth facing side of Mars in our night time would be more valuable to us than any Mars rover.
Or, maybe right under the ground-path of the MRO.

I'd call someone an ass when they don't trust the link they give and deliberately misquote from it to back up a wrong statement.

Yeah.
Now if you could just find someone who did that.
The link and quote I provided, however, are right on.

Asteroid=big ass rock in space.
Meteroid=little ass rock in space.
Meteor=light show from either of the above burning through the atmosphere.
Meteorite=the remains of a meteoroid or asteroid after it has hit ground.

Badda bing.

This is simple definition type stuff. I really don't get why you've got this stick up your ass about it.

Probably the reason it was called an asteroid in the first place was to differentiate it from a comet, the other big dramatic thing that often smacks into planets.

This thing is big enough to do very serious damage to human arrangements on Earth. If it hits Mars, that will be the second major strike on a planet in just a few years. I'm beginning to wonder about the the ordinary calculations of odds for these things hitting a planet - one every so many millions of years hitting earth, etc.

I know Jupiter and even Mars are much more in the target range, but still - -

Yeah.
Now if you could just find someone who did that.
The link and quote I provided, however, are right on.

Asteroid=big ass rock in space.
Meteroid=little ass rock in space.
Meteor=light show from either of the above burning through the atmosphere.
Meteorite=the remains of a meteoroid or asteroid after it has hit ground.

Badda bing.

This is simple definition type stuff. I really don't get why you've got this stick up your ass about it.

It's because you, or I or someone else said something that he disagrees with. That automatically makes the person wrong because they READ it some where and he maintains that if it in a book it's WRONG!!!!

Badda-ding, badda bing. Simple as that.

Does anyone now when this smurf will crash into mars?

Well gents, as far as impact craters go, the energy of impact is of far more significance than slightly different regional densities or even the difference in the gravitational field of the planet, especially given the relatively comparable nature of the earth and mars.

A given impactor size at a given impact energy will leave about the same sized hole on earth or mars. What will be different is the altitude that the ejecta will reach. Obviously it will go quite a bit higher on mars.

I don't want to quibble but I'd have thought that, everything else being equal, the size of the crater on earth woild be larger because of the acelaration due to gravity, giving a bigger value for the kinetic energy.I shall use round numbers for the sake of simplicity. Acceleration due to gravity on earth = 30' per sec^2 and 10' per sec^2 on mars. If we square these numbers we get a value of 900 for earth and 100 for mars, a ratio of 9:1. Surely that would make some difference.

In practice, the much greater density of earth's atmosphere would burn up a proportion of the asteroid as well as deccelerating it.

Apologies for not using metric measure but I'm going on what I learned some sixty years ago

Merry Christmas all

It is about as large as the one that hit in New Mexico, Meteor crater. It only has a one in seventyfive percent chance of hitting Mars and IF it hits , it will hit the very southermost area. :)

I don't want to quibble but I'd have thought that, everything else being equal, the size of the crater on earth woild be larger because of the acelaration due to gravity, giving a bigger value for the kinetic energy.I shall use round numbers for the sake of simplicity. Acceleration due to gravity on earth = 30' per sec^2 and 10' per sec^2 on mars. If we square these numbers we get a value of 900 for earth and 100 for mars, a ratio of 9:1. Surely that would make some difference.

In practice, the much greater density of earth's atmosphere would burn up a proportion of the asteroid as well as deccelerating it.

Apologies for not using metric measure but I'm going on what I learned some sixty years ago

Merry Christmas all
Well, I was going to anticipate that point, but I was too lazy to at the time.

If two equivalent asteroids were held above earth and mars and dropped form the same height, it would be as you said.

But the asteroid and the planet already have some very high relative speed. Their orbits are (we can assume) not common. So, while the gravity of the planet will have some definite effect, I would estimate it to minimally alter the existing speed difference as the two bodies come together. I suppose some fairly simple calculations could settle how much additional delta V the gravity of earth vs mars gives the asteroid (assuming all other trajectory parameters are the same) that is already closing at some tens of km/sec.

This is my physical intuition talking here. No doubt the respective gravities of earth and mars will "suck" the asteroid in and add additional speed. It's just the magnitude of the additional delta V vs the already existing speed that I suspect is not that significant.

I'd love to be proven wrong here if someone was willing to do the calculations?

I also suspect that the earths atmosphere, for a good sized asteroid moving at 17 to 20 km/sec would not be "noticed" much by the asteroid in the 1 to 2 seconds it took to pass through the dense portion of the atmosphere.

Well, I was going to anticipate that point, but I was too lazy to at the time.

If two equivalent asteroids were held above earth and mars and dropped form the same height, it would be as you said.

But the asteroid and the planet already have some very high relative speed. Their orbits are (we can assume) not common. So, while the gravity of the planet will have some definite effect, I would estimate it to minimally alter the existing speed difference as the two bodies come together. I suppose some fairly simple calculations could settle how much additional delta V the gravity of earth vs mars gives the asteroid (assuming all other trajectory parameters are the same) that is already closing at some tens of km/sec.

This is my physical intuition talking here. No doubt the respective gravities of earth and mars will "suck" the asteroid in and add additional speed. It's just the magnitude of the additional delta V vs the already existing speed that I suspect is not that significant.

I'd love to be proven wrong here if someone was willing to do the calculations?

I also suspect that the earths atmosphere, for a good sized asteroid moving at 17 to 20 km/sec would not be "noticed" much by the asteroid in the 1 to 2 seconds it took to pass through the dense portion of the atmosphere.

Thanks for pointing out my SMALL oversight. I did a rough calculation which suggests that from a distance of 1 mile above earth and mars respectively the addition velocities would be about 392 mph and 218 mph. As you say small beer compared to the original velocity of the asteroid . I estimate , using 1/2 m V^2 that the kinetic energy in both cases would be increased byabout 8K M and 2.4K M respectively.

For the sake of comparison with your figures, I have translated the velocities into metric measure on the basis of 1m=3'. They work out as 191m/sec and 106m/sec respectively. Obviously. these value will be larger if we were to calculate them from the time the asteroid enters earth's atmosphere as opposed to my values based on a height of 1 mile. They would, however, still be insignificant , in relation to 17-20km/sec.

This asteoid is most probably going to miss the opportunity rover But what are the changes that it would feel the resulting earthquake and could it possible see the ejecta in the high atmosphere?

The region is known to had water in the past resent theories predict that there would be large sulpher deposits could it's impact be measured in the atmosphere composition and could this have a effect on the temprature?

MRO to track possible asteroid impact

"New Mexico Tech's Magdalena Ridge Observatory (http://observatories.hodar.com/mro/index.html) is already making its mark in the annals of astronomy research after being recently tasked by NASA to make detailed observations of an asteroid that is now given a 1 in 75 chance of hitting Mars on January 30.
On Dec. 18, observatory researchers began tracking the asteroid, designated 2007 WD5, with the research facility's 2.4-meter telescope."

Read more (http://www.dchieftain.com/news/76739-12-26-07.html)

Latitude 33 58 36 S, Longitude –107 11 05

Is it possible to deflect it ? With nukes or something ?

Hum,
unfortunatly, not this time.

But there is ample time, if it misses, to get better knowledge of its orbit and launch a constellation of nuclear warheads so that we can finally destroy that face, once and for all.

Hum,
unfortunatly, not this time.

But there is ample time, if it misses, to get better knowledge of its orbit and launch a constellation of nuclear warheads so that we can finally destroy that face, once and for all.

I was thinking more along the lines of deflecting it towards us..
Wouldn't it be great to study the impact and the consequences ?
It would also mean a serious increase in the funding of research that deals with this kind of thing.

Hum,
yeah, i would be fascinating.
But it smacks of you being on the side of the Arachnids.

But it smacks of you being on the side of the Arachnids.

So ?

I was thinking more along the lines of deflecting it towards us.. ....

you would kill my children because it would be interesting to see how they would die??

you would kill my children because it would be interesting to see how they would die??

Sure.. ;)

I was kidding of course.. lol

Woo-Hoo!!!:yay:

The odds were increased to 1-in-25 (http://news.yahoo.com/s/ap/20071228/ap_on_sc/mars_asteroid;_ylt=AtskgwfyAFX3g0QUvm83eXoPLBIF) this week after a Ph.D. student pored through the archives and plotted the asteroid's motions before its official discovery. The new information allowed scientists to improve their calculations of the asteroid's orbit and flight path.

"Pre-discovery observations of asteroid 2007 WD5, taken on November 8, 2007 have allowed its orbit to be refined and the uncertainties for the late January Mars encounter have been improved. The impact probability resulting from the recent orbit refinement has increased to a surprising 3.9% (about 1 in 25 odds)...In the unlikely event of an impact, the time would be 2008 January 30 at 10:56 UT (2:56 a.m. PST) with an uncertainty of a few minutes."

Source (http://neo.jpl.nasa.gov/news/news153.html)

Woo-Hoo!!!:yay:

The odds were increased to 1-in-25 (http://news.yahoo.com/s/ap/20071228/ap_on_sc/mars_asteroid;_ylt=AtskgwfyAFX3g0QUvm83eXoPLBIF) this week after a Ph.D. student pored through the archives and plotted the asteroid's motions before its official discovery. The new information allowed scientists to improve their calculations of the asteroid's orbit and flight path.
'Course, that probably also increases the likelyhood of a "deflection shot" which ends up comin' right at us.

You got a catcher's mitt ?

:D

Everyone starts off with a little learning. It's all in the application of the learning.

The problem comes in when someone applies " a little learning" to something that requires a lot more.

The entire poem:

A little learning is a dangerous thing ;
Drink deep, or taste not the Pierian spring :
There shallow draughts intoxicate the brain,
And drinking largely sobers us again.
Fired at first sight with what the Muse imparts,
In fearless youth we tempt the heights of Arts ;
While from the bounded level of our mind
Short views we take, nor see the lengths behind,
But, more advanced, behold with strange surprise
New distant scenes of endless science rise !
So pleased at first the towering Alps we try,
Mount o’er the vales, and seem to tread the sky ;
The eternal snows appear already past,
And the first clouds and mountains seem the last ;
But those attained, we tremble to survey
The growing labours of the lengthened way ;
The increasing prospect tires our wandering eyes,
Hill peep o’er hills, and Alps on Alps arise !

Alexander Pope

Hum,
unfortunatly, not this time.

But there is ample time, if it misses, to get better knowledge of its orbit and launch a constellation of nuclear warheads so that we can finally destroy that face, once and for all.

All that need be done is to explode a 10 megaton warhead approxamatly a half of a mile away from the asteroid and the shock wave will deflect it enough for it not to create any problems.

Well, I was going to anticipate that point, but I was too lazy to at the time.

If two equivalent asteroids were held above earth and mars and dropped form the same height, it would be as you said.

But the asteroid and the planet already have some very high relative speed. Their orbits are (we can assume) not common. So, while the gravity of the planet will have some definite effect, I would estimate it to minimally alter the existing speed difference as the two bodies come together. I suppose some fairly simple calculations could settle how much additional delta V the gravity of earth vs mars gives the asteroid (assuming all other trajectory parameters are the same) that is already closing at some tens of km/sec.

This is my physical intuition talking here. No doubt the respective gravities of earth and mars will "suck" the asteroid in and add additional speed. It's just the magnitude of the additional delta V vs the already existing speed that I suspect is not that significant.

I'd love to be proven wrong here if someone was willing to do the calculations?



For an asteroid with an initial relative speed of 20 km/sec, the impact speed difference between Earth and Mars works out to about 2.29 Km/sec. In terms of kinetic energy, the Earth impact would be about 23% more energetic.

For an asteroid with an initial relative speed of 20 km/sec, the impact speed difference between Earth and Mars works out to about 2.29 Km/sec. In terms of kinetic energy, the Earth impact would be about 23% more energetic.
Excellent! Thank you very much. That's significant.

Excellent! Thank you very much. That's significant.

With what I could find out with a quick search, 2007 WD5 should have a initial relative velocity to Mars of around 12.5 km/sec. With this initial speed, the Earth/Mar's impact velocity difference comes out to a about 24.5% and the Energy of Impact difference to over 50%.

With what I could find out with a quick search, 2007 WD5 should have a initial relative velocity to Mars of around 12.5 km/sec. With this initial speed, the Earth/Mar's impact velocity difference comes out to a about 24.5% and the Energy of Impact difference to over 50%.

Heh! So much for Kaneda's statements about forming a larger crater on Mars! :bugeye:

Thank you very much. :)

Heh! So much for Kaneda's statements about forming a larger crater on Mars! :bugeye:

You should ask your teacher to help you with your reading skills as they still need work. I said Mars would have a larger crater than Earth from a similar impact and that a large impact on Mars would be good for astronomers on Earth. I never said there would be a large crater.

For an asteroid with an initial relative speed of 20 km/sec, the impact speed difference between Earth and Mars works out to about 2.29 Km/sec. In terms of kinetic energy, the Earth impact would be about 23% more energetic.

The gravitational pull on such and object would only differ between Mars and Earth very close up and for an object moving at 20k/s, that is not many seconds to accelerate it. There is also the point that Earth has a very dense atmosphere which would actually tend to slow down such a body (as well as heating it up) while Mars has a very thin atmosphere. Also as I have pointed out before, with just a third of the gravity, material ejected into the air will go far higher and stay in the air far longer. Mars has a density of 3.9 compared to Earth's 5.5 (that of water), allowing that Mars is also believed to have an iron core. The 23% difference will be cancelled by the softer surface of Mars, allowing for more damage by an impact.

Janus58. I never cared a lot for poetry. Often just a difficult way of telling us what we already know. Pope made a number of generalisations which are quite idiotic when read on their own :

Amusement is the happiness of those who cannot think.

Fools admire, but men of sense approve.

Man: the glory, jest, and riddle of the world.

Our passions are like convulsion fits, which, though they make us stronger for a time, leave us the weaker ever after.

The gravitational pull on such and object would only differ between Mars and Earth very close up and for an object moving at 20k/s, that is not many seconds to accelerate it. There is also the point that Earth has a very dense atmosphere which would actually tend to slow down such a body (as well as heating it up) while Mars has a very thin atmosphere. Also as I have pointed out before, with just a third of the gravity, material ejected into the air will go far higher and stay in the air far longer. Mars has a density of 3.9 compared to Earth's 5.5 (that of water), allowing that Mars is also believed to have an iron core. The 23% difference will be cancelled by the softer surface of Mars, allowing for more damage by an impact.

Two points: Can you explain why you believe/ know that the density of water is 5.5 and what units you are using.

How "more damage" would not meam a larger crater. You have just claimed that you never said the crater on mars would be larger than that on earth

The gravitational pull on such and object would only differ between Mars and Earth very close up and for an object moving at 20k/s, that is not many seconds to accelerate it.

Either planet will start effecting the asteroid once it enters the planet's Gravitational Sphere of Influence( that region where the planet's gravitational effect exceeds that of the Sun's.)

For the Earth, the radius of this sphere is 927,000 km and for Mars, (on average) 577,000 km. (even though Mars has only 1/10 the mass of the Earth, it is (on average)50% further from the Sun, which drops the Sun's gravitational pull to 43% of that at the Earth's orbital distance.

Traveling at the estimated initial 12.5 km/sec that the astreroid will have relative to Mars, it will spend a little under 13 hrs being accelerated by Mars' gravity, and would spend a little under 21 hrs being accelerated by Earth's gravity before impact.

Just for the fun of it, I figured out how accurate they have to be in predicting the asteroid's trajectory in order to get that 4% chance of impact.

As I mentioned in the last post, once the asteroid enters Mars' GSI, Mars will begin to effect its trajectory. This give the asteroid a little larger target to hit. If the asteroid's initial trajectory when entering the GSI would cause the asteroid to miss Mars by a small enough margin, Mars' gravity will dflect the trajectory into an impact.

In this particular instance, the asteroid could "miss" Mars by 400 km and still impact it.

This means that the asteriod has to "hit" a cross section with an area of 4467483 km² to result in an impact. If there is a 4% chance of the asteroid hitting this cross section, then the the range of error in the asteriod's position when it reaches Mars is +/-18,800 km.

Two points: Can you explain why you believe/ know that the density of water is 5.5 and what units you are using.

How "more damage" would not meam a larger crater. You have just claimed that you never said the crater on mars would be larger than that on earth


5.5 (that of water), as in 5.5 times that of water. You can't leave some people any opening here.

I have given reasons a number of times why I thought the an impact on Mars would produce a larger crater than the same impact on Earth.

Janus58. At those extreme distances, I think we are talking about if the asteroid is floating around that area for a few months or so we would see the effect of this gravity pull. If something is moving at 20 kms/sec, Earth is moving at 18 km/sec and Mars about 16 km/sec, I think the object is going to have to be close in before we notice any effect on it. The atmosphere itself could do serious damage to such an object as it gas pockets inside reacting with explosive force, even blowing some small objects up into smaller objects.

A asteroid would have to move through a 100 times more atmosphere in earths case, I think that's the most mayor reason why craters on mars would be larger.

Just for the fun of it, I figured out how accurate they have to be in predicting the asteroid's trajectory in order to get that 4% chance of impact.

As I mentioned in the last post, once the asteroid enters Mars' GSI, Mars will begin to effect its trajectory. This give the asteroid a little larger target to hit. If the asteroid's initial trajectory when entering the GSI would cause the asteroid to miss Mars by a small enough margin, Mars' gravity will dflect the trajectory into an impact.

In this particular instance, the asteroid could "miss" Mars by 400 km and still impact it.

This means that the asteriod has to "hit" a cross section with an area of 4467483 km² to result in an impact. If there is a 4% chance of the asteroid hitting this cross section, then the the range of error in the asteriod's position when it reaches Mars is +/-18,800 km.
a nice explenation on how mars got's his 2 moons I asume our moon would prevent such objects to ever reach a (million/billion years) stable orbit, and closer to the sun it would be the sun preventing it.

A asteroid would have to move through a 100 times more atmosphere in earths case, I think that's the most mayor reason why craters on mars would be larger.
Also parasitic drag on any debris lofted by the impact is less in the Martian atmosphere. This doesn't affect displacement but it does affect the propagation of impact debris, mainly how far it is dispersed from ground zero and how much falls back into the resultant crater.

5.5 (that of water), as in 5.5 times that of water. You can't leave some people any opening here.

I have given reasons a number of times why I thought the an impact on Mars would produce a larger crater than the same impact on Earth.

Sorry, got you wrong on the crater. But you must accept that 5.5( that of water) suggests that water has a specific gravity 5.5. Also it is unnecessary to mention water at all because, unless stated otherswise , it is implicit in the definition of density/specific gravity.

Janus58. At those extreme distances, I think we are talking about if the asteroid is floating around that area for a few months or so we would see the effect of this gravity pull. If something is moving at 20 kms/sec, Earth is moving at 18 km/sec and Mars about 16 km/sec, I think the object is going to have to be close in before we notice any effect on it.
I've crunched the numbers. For an asteroid with an inital relative speed of 12.5 km/sec (the estimated relative speed of this particular asteroid upon reaching the region of Mars) Mars' gravity would add 1km/sec additional velocity and Earth's gravity would add an additional 4km/sec. The additional velocity is due to the accumulated effect of each planet's gravity, from the time the asteroid enters the GSI until impact.

BTW, the Earth's orbital speed is 30 km/sec and for Mars 24 km/sec. The relative velocity of the asteroid WRT to Mars is due to the difference between its oribital velocity and Mars'. Since the asteriod is "coming up from behind" Mars, so to speak, the relative veloicty is less than either of the two's orbital velocities.

Also as I have pointed out before, with just a third of the gravity, material ejected into the air will go far higher and stay in the air far longer.This has nothing to do with the actual size of the crater, only how far the material ejected from the crater will travel.

Mars has a density of 3.9 compared to Earth's 5.5 (that of water), allowing that Mars is also believed to have an iron core. The 23% difference will be cancelled by the softer surface of Mars, allowing for more damage by an impact.

You can't make that generalization. "Less dense" does not equal "softer". (For example, of the two, diamond is much less dense than lead and is also much harder than lead.) The hardness of the Martian surface would have more to do with its chemcial make-up than its density.

Janus58. I'm old enough to still think in miles but kilometres are used in many cases. I forgot to convert the miles into km for orbital speeds.

Mars is said to have an iron core too but has a far lower overall density than Earth. This despite lots of metal oxides on it's surface.

I doubt that much diamond would form on the surface of Mars. Diamond is hard as it is because of pressure on it, so forms lower down, so not relevant here.

Janus58. I'm old enough to still think in miles but kilometres are used in many cases. I forgot to convert the miles into km for orbital speeds.
your not working for NASA are you (http://www.cnn.com/TECH/space/9909/30/mars.metric.02/)? :bugeye:

your not working for NASA are you (http://www.cnn.com/TECH/space/9909/30/mars.metric.02/)? :bugeye:
Heh.. :cool:

Janus58. I'm old enough to still think in miles but kilometres are used in many cases. I forgot to convert the miles into km for orbital speeds.

Mars is said to have an iron core too but has a far lower overall density than Earth. This despite lots of metal oxides on it's surface.

I doubt that much diamond would form on the surface of Mars. Diamond is hard as it is because of pressure on it, so forms lower down, so not relevant here.

Whoever said anything about diamonds existing on Mars? It was simply an example that density and hardness do not go hand in hand.

Neither did I dispute that Mar's crust is less dense than the Earth's. Estimates place it around 70-75% of that of the Earth's. But it is also estimated that Mars' crust is more rigid than the Earth's.

The point being that you can not use density as a reliable gauge of how the surface will react to an impact.

Whoever said anything about diamonds existing on Mars? It was simply an example that density and hardness do not go hand in hand.

Neither did I dispute that Mar's crust is less dense than the Earth's. Estimates place it around 70-75% of that of the Earth's. But it is also estimated that Mars' crust is more rigid than the Earth's.

The point being that you can not use density as a reliable gauge of how the surface will react to an impact.

Kind of like Lead vs Aluminum.

how acurate would this be
http://janus.astro.umd.edu/astro/impact/

Hi, Asteroid Watchers, I heard yesterday thst the chances of a hit have been reduced to 20:1
Keep tuned in

your not working for NASA are you (http://www.cnn.com/TECH/space/9909/30/mars.metric.02/)? :bugeye:

Did you ever read Punch magazine? They had some great covers. A favourite of mine were a group of skydivers holding hands in a circle on the sea bottom and one is saying to another; "I'll never get used to these metric altimeters".

Another favourite has a UFO landed in America and a number of top people are there, including the top brass. The ramp of the UFO is open and down it are walking (alien) humans dressed in red Indian clothing. One Government man is saying to another; "God, this is going to be embarrassing."

The unusual strength of light materials usually comes about through great pressure forming the molecular structure into certain shapes, as in diamonds. That is not going to occur on the surface of a planet but only deep down.

Did you ever read Punch magazine?
never even heard of sorry
The unusual strength of light materials usually comes about through great pressure forming the molecular structure into certain shapes, as in diamonds. That is not going to occur on the surface of a planet but only deep down.
planets are dynamic what was down a thousand years ago when it was formed can now by quit up, it all depends where it would strike I gues, is there a lot of ice in the soil, is there a lot of comprsionable materials in the soil at witch angle does the impact happen, etc

It's not gonna hit!!!

It's not gonna hit!!!

:bawl:

Not only is it not going to hit Mars, its not even likely now that Mars will deflect it enough to create a risk of a future Earth impact.

The asteroid's present orbit has a perihelion that is outside that of the Earth's orbit by about 5 million km. In order for a possible future Earth mpact to be possible, Mar's would have had to deflect the asteroid into a new orbit with a lower perhelion.

By my calculations this means that the asteroid would have to miss Mars by a maximum of 4130 km.

Present estimates place the asteroid on a path that will miss Mars by over 25,000 kilometers, with a small chance that it could pass within 3970 km. While this lower figure is within my calculated window, it is on the outside limb of the asteroid's possible path, which puts the probability as pretty low.

From a paper on the non impact, the asteroid has been calculated to pass near planet Mars at the minimum distance of 8.4 ±1.1 Mars Radius

(The average radius of Mars is 3390 km.)