The Feats
Context and all such exposition
As we learn, upon the moment Moriarty's death or the like was confirmed (though the only one to kick the bucket at the time was Bael the Demon Pillar?), Bennu became the 7th bullet controlled by the devil to be fired to destroy the planet through Moriarty's literal story plot contrivance bullshit plan. As the above exposition explains, Bennu only became the bullet upon this requirement being met and had not been magically influenced before this moment in time.
Apparently Moriarty losing his protagonist plot armor causes the meteor to no longer be a magic bullet, but all that really does itself is remove the Nasu conceptual bullshit that makes otherwise mundane objects difficult to deal with. The speed at which it would have been accelerated to in order to tug it in Earth's general direction would still remain.
Anyway.
We learn they have less than 5 minutes from the time this happens until Bennu impacts Shinjuku. That said, it's more like 2 minutes as Moriarty speeds it up using the Holy Grail to further empower himself (making him about as powerful as a Demon Pillar for context/powerscaling purposes).
So I'll treat this as being of 2 models.
One where this is occurring between on February 1st per them musing its the start of February indirectly here.
The second will be from the date Bennu was discovered on September 11 1999 and when it was closest to the planet on September 22 16:20 1999 on the assumption the reference to February was from Chaldea's frame of reference.
So, to reinforce context again?
Bennu hasn't started towards Shinjuku yet here
Explanation of Phantom Spirit Der Freischutz powers here
Mentions how Bennu was observed in 1999 here, possibly indicating Shinjuku's singularity is around that particular date as opposed to February. This is so as he's talking about it in the context of it having approached Earth that year and many years afterward. This fact is why he reasons Moriarty plans to use it as his bullet.
The demon pillar dies and Bennu starts on its way toward Shinjuku here
Explanation of the 7th bullet of the Phantom Spirit's power and how it was fired upon "Moriarty's death being confirmed" here, 5 minutes initially until bullet arrives to Shinjuku from initial position here, EMIYA Alter bitches about how it being a magic bullet rather than just a meteor makes it near impossible to stop with their swords here, Moriarty implies he can't do anything to harm Ritsuka as he is the person he cares about and what the 7th bullet is aimed to hit in Shinjuku here, Moriarty empowers himself with the Grail and shaves down Bennu's arrival time to a time frame of 2 minutes here, We get confirmation Bennu's been turned back into a normal meteor rather than magic bullet and that EMIYA Alter can now act to try and destroy it here, EMIYA Alter also confirms the only thing turning from magic bullet to meteor did was remove the conceptual bullet as Bennu was still a "meteor hell-bent on destroying Earth" here.
So back to this calculator here.
Now, first model with February.
If the link doesn't already have it entered into "Time Span", edit it as 1999-02-01 for the start time and 1999-09-22 16:20 for the stop time (that's the time Bennu was at it's closest in 1999) respectively.
"Delta" is what we're looking at on the generated output table. Delta = number of AU from the observer on Earth essentially (double check me on that though, I'm half awake).
1 AU = 149,597,870,700 meters (source here)
So, on February 1st?
Bennu was 1.408 AU away or 210,633,801,946 meters
And 120 seconds is the travel time
Bennu Speed (02/01/1999) = 1,755,281,683 m/s or 5.851C
Obviously, I can't do a KE for something FTL, so this model will instead rather just appeal to being some form of extinction level event as this was never a meteor with the raw power to outright nuke the world in the first place, but rather it was going to bore its way to the core and all that kind of fun.
So, guess something like at least the Chixulub Impact. if not the worse given this didn't kill everything or reach to the core *shrugs*
I've seen ~100 teratons cited for the event, but the wikipedia citation lists a range of 1.3 * 10^24 joules to 5.8 * 10^25 joules or otherwise known as 310.707 teratons to 1.386 petatons
Now model 2
On September 11 1999 Bennu was about 0.05 AU or 7,479,893,535 meters away according to this here.
On September 22 at 16:20? Bennu was about 0.0147 AU or 2,199,088,699 meters away according to the chart at the bottom of the page here.
Bennu Speed (09/11/1999) = 62,332,446 m/s or 0.208C
Bennu Speed (09/22/1999) = 18,325,739 m/s or 0.061C
This I can do a KE for (both regular Newtonian and Relativistic respectively)
Bennu's mass is some ~6 * 10^10 kilograms as said here.
Relativistic Calculator for 09/11/1999 here
Bennu Yield (09/11/1999) = 1.205 * 10^26 joules or 28.8 petatons
Energy = 0.5mv^2 for 09/22/1999
Bennu Yield (09/22/1999) = 10,074,981,296,883,630,000,000,000 joules or 2.408 petatons
So... extinction level events as Moriarty wanted. Cool.
Context and all such exposition
As we learn, upon the moment Moriarty's death or the like was confirmed (though the only one to kick the bucket at the time was Bael the Demon Pillar?), Bennu became the 7th bullet controlled by the devil to be fired to destroy the planet through Moriarty's literal story plot contrivance bullshit plan. As the above exposition explains, Bennu only became the bullet upon this requirement being met and had not been magically influenced before this moment in time.
Apparently Moriarty losing his protagonist plot armor causes the meteor to no longer be a magic bullet, but all that really does itself is remove the Nasu conceptual bullshit that makes otherwise mundane objects difficult to deal with. The speed at which it would have been accelerated to in order to tug it in Earth's general direction would still remain.
Anyway.
We learn they have less than 5 minutes from the time this happens until Bennu impacts Shinjuku. That said, it's more like 2 minutes as Moriarty speeds it up using the Holy Grail to further empower himself (making him about as powerful as a Demon Pillar for context/powerscaling purposes).
So I'll treat this as being of 2 models.
One where this is occurring between on February 1st per them musing its the start of February indirectly here.
The second will be from the date Bennu was discovered on September 11 1999 and when it was closest to the planet on September 22 16:20 1999 on the assumption the reference to February was from Chaldea's frame of reference.
So, to reinforce context again?
Bennu hasn't started towards Shinjuku yet here
Explanation of Phantom Spirit Der Freischutz powers here
Mentions how Bennu was observed in 1999 here, possibly indicating Shinjuku's singularity is around that particular date as opposed to February. This is so as he's talking about it in the context of it having approached Earth that year and many years afterward. This fact is why he reasons Moriarty plans to use it as his bullet.
The demon pillar dies and Bennu starts on its way toward Shinjuku here
Explanation of the 7th bullet of the Phantom Spirit's power and how it was fired upon "Moriarty's death being confirmed" here, 5 minutes initially until bullet arrives to Shinjuku from initial position here, EMIYA Alter bitches about how it being a magic bullet rather than just a meteor makes it near impossible to stop with their swords here, Moriarty implies he can't do anything to harm Ritsuka as he is the person he cares about and what the 7th bullet is aimed to hit in Shinjuku here, Moriarty empowers himself with the Grail and shaves down Bennu's arrival time to a time frame of 2 minutes here, We get confirmation Bennu's been turned back into a normal meteor rather than magic bullet and that EMIYA Alter can now act to try and destroy it here, EMIYA Alter also confirms the only thing turning from magic bullet to meteor did was remove the conceptual bullet as Bennu was still a "meteor hell-bent on destroying Earth" here.
So back to this calculator here.
Now, first model with February.
If the link doesn't already have it entered into "Time Span", edit it as 1999-02-01 for the start time and 1999-09-22 16:20 for the stop time (that's the time Bennu was at it's closest in 1999) respectively.
"Delta" is what we're looking at on the generated output table. Delta = number of AU from the observer on Earth essentially (double check me on that though, I'm half awake).
1 AU = 149,597,870,700 meters (source here)
So, on February 1st?
Bennu was 1.408 AU away or 210,633,801,946 meters
And 120 seconds is the travel time
Bennu Speed (02/01/1999) = 1,755,281,683 m/s or 5.851C
Obviously, I can't do a KE for something FTL, so this model will instead rather just appeal to being some form of extinction level event as this was never a meteor with the raw power to outright nuke the world in the first place, but rather it was going to bore its way to the core and all that kind of fun.
So, guess something like at least the Chixulub Impact. if not the worse given this didn't kill everything or reach to the core *shrugs*
I've seen ~100 teratons cited for the event, but the wikipedia citation lists a range of 1.3 * 10^24 joules to 5.8 * 10^25 joules or otherwise known as 310.707 teratons to 1.386 petatons
Now model 2
On September 11 1999 Bennu was about 0.05 AU or 7,479,893,535 meters away according to this here.
On September 22 at 16:20? Bennu was about 0.0147 AU or 2,199,088,699 meters away according to the chart at the bottom of the page here.
Bennu Speed (09/11/1999) = 62,332,446 m/s or 0.208C
Bennu Speed (09/22/1999) = 18,325,739 m/s or 0.061C
This I can do a KE for (both regular Newtonian and Relativistic respectively)
Bennu's mass is some ~6 * 10^10 kilograms as said here.
Relativistic Calculator for 09/11/1999 here
Bennu Yield (09/11/1999) = 1.205 * 10^26 joules or 28.8 petatons
Energy = 0.5mv^2 for 09/22/1999
Bennu Yield (09/22/1999) = 10,074,981,296,883,630,000,000,000 joules or 2.408 petatons
So... extinction level events as Moriarty wanted. Cool.
Final Tally
Model 1
Bennu Yield Range (based on Chixulub Impact something or other) = 310.707 teratons to 1.386 petatons
Bennu Speed (02/01/1999) = 1,755,281,683 m/s
Model 2
Bennu Yield (09/11/1999) = 28.8 petatons
Bennu Yield (09/22/1999) = 2.408 petatons
Bennu Speed (09/11/1999) = 62,332,446 m/s
Bennu Speed (09/22/1999) = 18,325,739 m/s