Asteroid ZTm0038 with a >3% impact probability • Hacker News Board

Re: Asteroid ZTm0038 with a >3% impact probability

#21

Post by FredPret » Tue, Aug 15, 2023, 8:08 PM UTC

I plugged this into neal.fun/asteroid-launcher.

I'm not sure if I did it right (I used the 15.84 km/s as impact speed, picked 45 deg impact, and an iron asteroid). It's certainly serious - millions dead - especially if it hits Manhattan as neal.fun seems to invite you doing, but not world-ending.

Re: Asteroid ZTm0038 with a >3% impact probability

#22

Post by AbrahamParangi » Tue, Aug 15, 2023, 8:10 PM UTC

xwdv wrote: post #3

Not threatening, mostly harmless.

At 400m diameter we should expect an impact energy of ~3Gt, which would be one of the most energetic events in human history, if not the most.

For a comparison, the Lake Toba eruption (which is suspected of causing homo sapiens to almost go extinct 76kya) is estimated to have been in the 1-2Gt range.

Re: Asteroid ZTm0038 with a >3% impact probability

#23

Post by hoten » Tue, Aug 15, 2023, 8:11 PM UTC

deepakg wrote: post #17

brink wrote: post #11

Earlier quoted context omitted.

How much of that would burn up in the atmosphere if it did hit?

This video has comparisons of devastation that would be caused by different sizes (around 7:50 mark) of asteroids: https://www.youtube.com/watch?v=4Wrc4fHSCpw

So a 500m is roughly a couple thousand or ten thousand times more than a Hiroshima nuke?

Re: Asteroid ZTm0038 with a >3% impact probability

#24

Post by post_break » Tue, Aug 15, 2023, 8:11 PM UTC

How long ago was it spotted. That's what I'm curious about, did we have any lead time?

Re: Asteroid ZTm0038 with a >3% impact probability

#25

Post by AbrahamParangi » Tue, Aug 15, 2023, 8:12 PM UTC

babelfish wrote: post #16

xwdv wrote: post #3

Not threatening, mostly harmless.

[flagged]

This seems like it's off by ~6 orders of magnitude

(see https://en.wikipedia.org/wiki/Impact_event)

Re: Asteroid ZTm0038 with a >3% impact probability

#26

Post by nocoiner » Tue, Aug 15, 2023, 8:13 PM UTC

hughes wrote: post #9

Impact time is in the past. Mission accomplished, everyone!

I must have put a decimal point in the wrong place or something. I always do that. I always mess up some mundane detail.

Re: Asteroid ZTm0038 with a >3% impact probability

#27

Post by arcticpeanuts » Tue, Aug 15, 2023, 8:14 PM UTC

I'm aware that it already passed its closest approach, but what does >3% even mean? 100% is >3%, but 3.000001% is >3% too. Was an impact certain at some point and the probability degraded to a bit above 3% over the course of the asteroid's trajectory? If so, I think I'd like to have a heads up when the probability is still closer to 100%, before it drops?

Re: Asteroid ZTm0038 with a >3% impact probability

#28

Post by blurbleblurble » Tue, Aug 15, 2023, 8:14 PM UTC

Looks pretty bad in this asteroid impact simulator: https://neal.fun/asteroid-launcher/

Re: Asteroid ZTm0038 with a >3% impact probability

#29

Post by throwaway5729 » Tue, Aug 15, 2023, 8:15 PM UTC

thatcherc wrote: post #6

I don't really know how to read this page, but it looks like the time of closest approach has already passed - > Closest approach time of impactors: t_min = 2023/08/14 04:48 TDB and t_max = 2023/08/15 12:22 TDB If so then we're all good. Can the poster or anyone else chime in with background on this?

I saw this tweet: https://twitter.com/ByronDrury/status/1691487518590402560?s=...

linking to https://cneos.jpl.nasa.gov/scout/#/object/ZTm0038

It has some cool graphs that seem to show a lot of uncertainty in closest approach time

[edited to fix second link]

Re: Asteroid ZTm0038 with a >3% impact probability

#30

Post by gs17 » Tue, Aug 15, 2023, 8:15 PM UTC

babelfish wrote: post #16

xwdv wrote: post #3

Not threatening, mostly harmless.

[flagged]

I would recommend using a calculator designed by experts, like https://impact.ese.ic.ac.uk/ImpactEarth/ImpactEffectsMap/ instead of ChatGPT. I get a low-end estimate of tens of megatons.