Editing Talk:3049: Incoming Asteroid

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Asteroids are surprisingly destructive even at small sizes - I remember reading somewhere that the Armageddon movie asteroid was supposed to be "the size of Arlington, Texas", but that it sounded too small so they changed it to "the size of Texas" which is a drastic size increase and also proportionally far more deadly. For scale, Arlington is 250 square km and Texas is 700 000 square km. The Chixulub asteroid that wiped out the dinosaurs was between 10 and 15 km across. If it was a perfect circle, it would have an area of between 79 and 176 sq km. Arlington would be 18 km across, still within "species" range, and Texas would be 944 km across, clearly in "new moon" territory. But it _sounds_ much cooler! [[User:Zakator|Zakator]] ([[User talk:Zakator|talk]]) 22:32, 10 February 2025 (UTC)
:And that's for asteroids with normal speed (for asteroid, which is still kinda fast). The level of danger asteroid means is proportional to kinetic energy, meaning proportional to mass and SQUARE of speed, so if it's faster, it gets to extinction level even when small ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:29, 10 February 2025 (UTC)
:: "for asteroids with normal speed" - which is generally orbital velocity. If much faster, it would have left the solar system by now. If much slower, it has fallen into the Sun already. All objects (even Teslas) at a given distance soon have similar velocities. --[[User:PRR|PRR]] ([[User talk:PRR|talk]]) 00:04, 11 February 2025 (UTC)
::: It could be going at ''a'' speed (similar to Earth, give or take, for the sake of being on an Earth-incident orbit) and yet have such different effects. If basically following the Earth (or leading it), it'll be relatively gentle, at least before you start considering the Earth's (and the asteroid's, in the event it's significantly large) gravity well pulling it. Well, 'gentle' in comparison to one doing the 'same speed' but in the anti-orbit, for a full head-on impact. Course, that's why we need to think of velocities, and in particular the relative ones. [[Special:Contributions/172.71.241.37|172.71.241.37]] 01:31, 11 February 2025 (UTC)
:::Considering just two-body physics... Escape speed for the Sun at the distance of Earth's orbit is 42 km/s, so that's the upper limit anything is likely to be going (otherwise it's just got one shot at us).  That would be something falling towards the Sun from a very large distance.  If the asteroid is moving in the opposite direction as Earth, that gets added to Earth's orbital speed of 30 km/s, for a total of 72 km/s.  On the other hand, Earth has an escape speed of 11 km/s at the surface, so that's the lower bound for an impact.  A 6.5x factor on speed is about a 40x factor on impact energy.  Which, I'm not sure exactly how that would scale devastation, but ... I'll take the low end for anything big, thanks. [[Special:Contributions/172.70.111.22|172.70.111.22]] 14:18, 11 February 2025 (UTC)

The 1m danger makes me think of the meteor impact that was caught on a home security camera last July in Prince Edward Island. But the Sky & Telescope article https://skyandtelescope.org/astronomy-news/hear-the-first-ever-recording-of-a-meteorite-slamming-into-the-ground/ says that it would have been only a 6-7 cm across. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 00:42, 11 February 2025 (UTC)

The sizes in the explanation are out of sync with the image. Has Randall updated it, or may it be location dependent? ~~Guest~~ 07:12, 11 February 2025 (UTC)
:I saw the comic before any explanation was put up and it was the same as it is now, all exactly powers of 10. But the labels aren't exactly at those spots, so people are probably estimating the exact point where the labels are at, though my interpretation would be that Randall meant for the labels to be attached to ranges rather than points. [[User:Tharkon|Tharkon]] ([[User talk:Tharkon|talk]]) 11:45, 11 February 2025 (UTC)
::Same here, all powers of 10.  I don't think it makes any sense at all to guess at where on the axis the labels are meant to be when the labels themselves give an explicit number. The labels should probably be the ranges, eg "1cm to 10cm", "10cm to 1m" and so on.[[User:Mazz0|Mazz0]] ([[User talk:Mazz0|talk]]) 14:00, 11 February 2025 (UTC)
:::There are small markers between the labeled spots, so it's not unreasonable to estimate which marker the ellipsis points to. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 14:41, 11 February 2025 (UTC)

"Good news everyone! We were supposed to make a delivery to the planet Tweenis 12 but it's been completely destroyed!" [[Special:Contributions/162.158.94.203|162.158.94.203]] 11:24, 11 February 2025 (UTC)


It's not the first comic comparing our reaction to different scales of cosmic events, even though the asteroid "happiness level" does not peak like the supernova chart: https://xkcd.com/2878/