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# Asteroid and atmosphere

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So I am wondering I know most asteroid break up on entry and burn. But an asteroid like this 4.1km going by how much of something like that would burn up and approximately what would the final size be that falls to earth?

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Did you have a specific asteroid in mind, given the exact size you gave?

It probably matters to some extent what it's made of - a rubble pile is going to be more affected than a lump of iron.

But regardless, something that large is probably going to reach the surface largely intact. Given the speed these objects move, they're likely to move from the edge of the atmosphere to the surface in less than 20 seconds (maybe 30 seconds if it comes in at a shallow angle) and that's not going to be enough time to abrade much material.

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4 minutes ago, Peter B said:

Did you have a specific asteroid in mind, given the exact size you gave?

It probably matters to some extent what it's made of - a rubble pile is going to be more affected than a lump of iron.

But regardless, something that large is probably going to reach the surface largely intact. Given the speed these objects move, they're likely to move from the edge of the atmosphere to the surface in less than 20 seconds (maybe 30 seconds if it comes in at a shallow angle) and that's not going to be enough time to abrade much material.

Cool

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There is an impact calculator, link below, just enter relevant parameters.

Starting with -

Observer distance from Impact: 100.00 km ( = 62.10 miles )

Projectile diameter: 4.00 km ( = 2.48 miles )

Projectile Density: 1500 kg/m3

Impact Velocity: 18.00 km per second ( = 11.20 miles per second )

Impact Angle: 45 degrees

Target Density: 2500 kg/m3

Target Type: Sedimentary Rock

Estimated damage -

Final Crater Diameter: 38.8 km ( = 24.1 miles )

Final Crater Depth: 890 meters ( = 2920 feet )

Time for maximum radiation: 2.24 seconds after impact

Visible fireball radius: 39.4 km ( = 24.5 miles )

The fireball appears 89.5 times larger than the sun

Thermal Exposure: 3.77 x 108 Joules/m2

Radiant flux (relative to the sun): 722

Clothing ignites

Much of the body suffers third degree burns

Newspaper ignites

Plywood flames

Deciduous trees ignite

Grass ignites

Seismic Effects:

The major seismic shaking will arrive approximately 20 seconds after impact.

Richter Scale Magnitude: 8.8

Air Blast:

The air blast will arrive approximately 5.05 minutes after impact.

Peak Overpressure: 1.15e+06 Pa = 11.5 bars = 163 psi

Max wind velocity: 822 m/s = 1840 mph

Sound Intensity: 121 dB (Dangerously Loud

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1 hour ago, L.A.T.1961 said:

There is an impact calculator, link below, just enter relevant parameters.

Starting with -

Observer distance from Impact: 100.00 km ( = 62.10 miles )

Projectile diameter: 4.00 km ( = 2.48 miles )

Projectile Density: 1500 kg/m3

Impact Velocity: 18.00 km per second ( = 11.20 miles per second )

Impact Angle: 45 degrees

Target Density: 2500 kg/m3

Target Type: Sedimentary Rock

Estimated damage -

Final Crater Diameter: 38.8 km ( = 24.1 miles )

Final Crater Depth: 890 meters ( = 2920 feet )

Time for maximum radiation: 2.24 seconds after impact

Visible fireball radius: 39.4 km ( = 24.5 miles )

The fireball appears 89.5 times larger than the sun

Thermal Exposure: 3.77 x 108 Joules/m2

Radiant flux (relative to the sun): 722

Clothing ignites

Much of the body suffers third degree burns

Newspaper ignites

Plywood flames

Deciduous trees ignite

Grass ignites

Seismic Effects:

The major seismic shaking will arrive approximately 20 seconds after impact.

Richter Scale Magnitude: 8.8

Air Blast:

The air blast will arrive approximately 5.05 minutes after impact.

Peak Overpressure: 1.15e+06 Pa = 11.5 bars = 163 psi

Max wind velocity: 822 m/s = 1840 mph

Sound Intensity: 121 dB (Dangerously Loud

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2 minutes ago, Damien99 said:

You would not want to be too close when it hit. Although I don't think it is an E.L.E.

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6 minutes ago, L.A.T.1961 said:

You would not want to be too close when it hit. Although I don't think it is an E.L.E.

What’s e.l.e.

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1 minute ago, Damien99 said:

What’s e.l.e.

Extinction level event.

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24 minutes ago, L.A.T.1961 said:

Extinction level event.

So why is it being claimed that this asteroid can potentially be a ELE if it hit earth?

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2 minutes ago, Damien99 said:

So why is it being claimed that this asteroid can potentially be a ELE if it hit earth?

Not sure, if its the one in the news recently its so far away its not a risk.

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1 hour ago, L.A.T.1961 said:

Not sure, if its the one in the news recently its so far away its not a risk.

These questions came from the one in the news. A lot of false media out there

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2 hours ago, Damien99 said:

So why is it being claimed that this asteroid can potentially be a ELE if it hit earth?

Claimed by who? Can you provide links to any reputable source making this claim?

I am assuming that you are talking about 1998 OR2, which will pass the Earth tomorrow. If so then latest information shows that it is only about half the size that you are claiming. At 2km across it would still be a bad day if it hit us, but not an extinction level event.

1998 OR2 is am Amor asteroid. It can approach close to the Earth, but does not actually cross Earth's orbit... in other words it can not impact the Earth.

Despite the fact that it can not hit us it is classified as a potentially hazardous asteroid (PHA). This is because, over long periods of time, small forces can act on asteroids and change their orbits. It is considered a PHA because, in several centuries,  maybe millennia, it's orbit may have changed so that it does cross the Earth (it's equally likely that it's orbit will take it further from the Earth than it does now).

The orbit of 1998 OR2 is very well known, it has been regularly observed since discovery in 1998 and there are prediscovery images of it stretching back to 1986. Because it's orbit is so well know impact with the Earth can be ruled out for several centuries at least.

Tomorrow it will pass by harmlessly at a distance 16x further than the moon. It won't even become visible to the naked eye.

In 2079 it will come closer still, passing at a distance of around 4.6x further than the moon.

1998 OR2 possess no threat to the Earth for the foreseeable future. How much destruction it would cause if it hit is largely irrelevant because it won't hit... not for many hundreds of years at the very least.

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1 hour ago, Waspie_Dwarf said:

Claimed by who? Can you provide links to any reputable source making this claim?

I am assuming that you are talking about 1998 OR2, which will pass the Earth tomorrow. If so then latest information shows that it is only about half the size that you are claiming. At 2km across it would still be a bad day if it hit us, but not an extinction level event.

1998 OR2 is am Amor asteroid. It can approach close to the Earth, but does not actually cross Earth's orbit... in other words it can not impact the Earth.

Despite the fact that it can not hit us it is classified as a potentially hazardous asteroid (PHA). This is because, over long periods of time, small forces can act on asteroids and change their orbits. It is considered a PHA because, in several centuries,  maybe millennia, it's orbit may have changed so that it does cross the Earth (it's equally likely that it's orbit will take it further from the Earth than it does now).

The orbit of 1998 OR2 is very well known, it has been regularly observed since discovery in 1998 and there are prediscovery images of it stretching back to 1986. Because it's orbit is so well know impact with the Earth can be ruled out for several centuries at least.

Tomorrow it will pass by harmlessly at a distance 16x further than the moon. It won't even become visible to the naked eye.

In 2079 it will come closer still, passing at a distance of around 4.6x further than the moon.

1998 OR2 possess no threat to the Earth for the foreseeable future. How much destruction it would cause if it hit is largely irrelevant because it won't hit... not for many hundreds of years at the very least.

Sorry the last article I saw it said something like 4km and 2 miles. Haven’t seen info yet it is only 2km. Does anyone know what it’s made of. Also what does amor mean?

this was the newest article I saw with info

Edited by Damien99

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7 minutes ago, Damien99 said:

Sorry the last article I saw it said something like 4km and 2 miles. Haven’t seen info yet it is only 2km. Does anyone know what it’s made of. Also what does amor mean?

this was the newest article I saw with info

Once again you are only seeing what you want to see and invent stuff. It describes the asteroid as:

Quote

This 1.8 to 4.1km large asteroid will come as close as 6.3 millions of km from us next April 29 – more than 16 times the average lunar distance: it will not hit us – becoming bright enough to be seen with modest optical equipment

Yet you are only seeing the upper limit.

It also describes the asteroid as potentially hazardous. No where does it mention an extinction level event.

So my question still stands:

1 hour ago, Waspie_Dwarf said:

Claimed by who? Can you provide links to any reputable source making this claim?

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6 minutes ago, Waspie_Dwarf said:

Once again you are only seeing what you want to see and invent stuff. It describes the asteroid as:

Yet you are only seeing the upper limit.

It also describes the asteroid as potentially hazardous. No where does it mention an extinction level event.

So my question still stands:

I posted the recent article that said 4km above, also does anyone know of any tracker that we can see it now, the only one I found went offline because of clouds and will resume in 20 hours but it would have passed already then

again as I posted a few minutes again this article says 4km

https://www.google.ca/amp/s/www.express.co.uk/news/science/1267536/Asteroid-news-4km-asteroid-Earth-close-approach-NASA-NEO/amp Article is from today I see the quote you stated 1-4 km which was quoted from weeks ago but the title from today says 4km so I thought that meant it found the final size

Edited by Damien99

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On 4/29/2020 at 7:56 AM, Damien99 said:

Sorry the last article I saw it said something like 4km and 2 miles. Haven’t seen info yet it is only 2km. Does anyone know what it’s made of. Also what does amor mean?

this was the newest article I saw with info

Amor asteroids are asteroids which pass close to the Earth but which don't cross the Earth's orbit. They're named after an asteroid called Amor, which is one such asteroid.

Because their orbits don't cross the Earth's orbit they can't collide with the Earth. But because some move close to planets (whether Earth or Mars) their orbits might be altered in the future, thus potentially turning them into threats.

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The Center for Near Earth Objects Studies, part of NASA, puts the diameter of asteroid 1998  OR2 at between 1.8 and 4.1 kilometers. One approach would be to average the two extremes, hence: 2.95, or rounded to 3 km.  This object passed nearest Earth at 00:16 GMT this morning, without incident.  It was imaged in radio waves from the Arecibo Observatory. The reflected waves  revealed a somewhat irregular object, tumbling through space with a rotation rate of approximately 3 & 1/2 hours.

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20 hours ago, bison said:

The Center for Near Earth Objects Studies, part of NASA, puts the diameter of asteroid 1998  OR2 at between 1.8 and 4.1 kilometers. One approach would be to average the two extremes, hence: 2.95, or rounded to 3 km.  This object passed nearest Earth at 00:16 GMT this morning, without incident.  It was imaged in radio waves from the Arecibo Observatory. The reflected waves  revealed a somewhat irregular object, tumbling through space with a rotation rate of approximately 3 & 1/2 hours.

That cool to know the site that was showing it live was down due to clouds