7 ms·
It missed Earth by 73,000 kilometers; Earth has radius 6,371 kilometers. (79371 * 79371) / (6371 * 6371) = 155.2 This was a game of darts in a galactic pub. T
by Syzygies 7y ago
It missed Earth by 73,000 kilometers; Earth has radius 6,371 kilometers.
(79371 * 79371) / (6371 * 6371) = 155.2
This was a game of darts in a galactic pub. The dart hit the dart board, but not the bullseye (Earth). One in every 155 times we play this game, it ends badly.
- rosser 7y agoAssuming no other conditions change, and that the object crosses Earth's orbit as the planet is passing by, and so on. I'd be willing to bet, however, that this object's orbit permutes a bit with every pass, especially dipping that deeply into the gravity wells of other, much more massive, objects.
- pault 7y agoOn galactic scales that's more like glancing off the ring of the bulls eye.
- Cacti 7y agoOn galactic scales it’s a meaningless analogy.
- eridius 7y agoHow does the math change when you take into account the fact that Earth exerts a gravitational pull on the asteroid?
- Skunkleton 7y agoInteresting question, not sure. As the speed of the astroid is goes up, the relevance of gravity goes down. As the speed goes down, the damage it can do also goes down, and also reduces the probability of an encounter.
- quickthrower2 7y agoAnd does that make it more likely to miss? Ie it gets slung around by gravity instead of hitting?
- lutorm 7y agoThe degree of gravitational focusing depends on the speed of the incoming object, but I seem to recall that for typical interplanetary velocities it's of order 1, ie not huge.
- dmckeon 7y agoIt may not change this encounter much, but it could change the orbit just enough for some future earth-orbit crossing - as could the gravitational effect of any of the other planets, their moons, and all the other asteroids change the orbits of anything out there. Solar systems can be messy places, over geologic time frames. Sometime, sooner or later, we will have a significant impact.
- kryogen1c 7y agoThinking out loud time! My favorite! To matter for a single pass, the object must be small and/or traveling slowly. Otherwise, itll just keep on cruising. Iteratively is a different story. Many objects repeatedly cross earths path. How that orbit changes over time i suppose is a function of the other gravity wells the objects pass when they arent near earth. I expect there are so many confounding gravities that only a certain belt\torus exists in the universe where, inside that torus, space stuff is capable of running into us. Side note: this article is clickbaity because it implies no one knew asteroids almost crash into us without us knowing, but thats not true. People know. There are hard reset buttons floating around in space and we might just press one without warning. https://en.m.wikipedia.org/wiki/Potentially_hazardous_object https://en.m.wikipedia.org/wiki/Potentially_hazardous_object
- probablybroken 7y agoWhy would the size of the object matter in this instance?
- kryogen1c 7y agoMass, not really size. The smaller the object relative to earth, the more its course is changed by earths gravity.
- probablybroken 7y agoYou may want to refer to Galileo's leaning tower of pisa experiment...
- gamedori 7y agoIt probably has no effect: objects that are not in stable orbits around the earth are going to be in hyperbolic orbits relative to the Earth's gravitational field. A dangerous asteroid would need a periapsis lower than the Earth's radius by a certain amount to hit the Earth, so the risk of collision is still roughly proportional to Area. If gravity is a factor I would expect it to be a high order term. Atmospheric effects are probably more significant.
- ls612 7y agoEven if it hit the earth the odds of it landing anywhere near a city are slim. 3/4 of the time it hits the ocean, Siberia, the Canadian north, or the Antarctic.
- StavrosK 7y agoSerendipitously cooling the surface of the earth down by exactly 2.2 C.
- HeWhoLurksLate 7y agoBring it, punk!
- pault 7y agoPerhaps the solution to climate change is dropping a rock the size of a stadium on Canada every few years.
- setr 7y agoMine some ice from an asteroid and drop it into the ocean, with larger blocks every few years as pollution increases :-)
- teamonkey 7y agoMuch of the ice would vaporise on entry. Water vapor is a greenhouse gas.
- quakenul 7y agoYes. But more importantly, that was a Futurama reference: https://www.youtube.com/watch?v=6cjx4gJFME0 https://www.youtube.com/watch?v=6cjx4gJFME0
- imtringued 7y agoIt can either both prevent sunlight from entering or leaving depending on the altitude.
- vkou 7y agoHow often do we play this game? How often would it hit something we care about on the dartboard?
- idlewords 7y agoYour math is off because the bullseye gravitationally attracts the dart
- sideshowb 7y agoOnly significantly so if the dart is going very slow
- deleted 7y ago[deleted]
- jarfil 7y agoHow often do we play this same game, though? If a 1Km size asteroid seems to hit the Earth about once every 500,000 years, it would seem like they would pass this close to the Earth only once every 32,000 years or so. So either the 500Ky figure is wrong, or we've been extremely lucky to witness a once-in-30Ky event, or we're missing something.
- mikeash 7y agoThis was only 100m. Those probably hit semi-regularly and would have usually gone unnoticed or at least unrecorded before modern times.
- gabia 7y agoIncredibly in Australia there are impact events recorded in indigenous oral tradition dating back thousands of years. http://www.aboriginalastronomy.com.au/content/topics/craters/ http://www.aboriginalastronomy.com.au/content/topics/craters...
- whamlastxmas 7y agoIt was described as "astronomically small" that something like this would hit us so I imagine there's factors not being considered here
- mr_toad 7y ago> One in every 155 times we play this game, it ends badly. That assumes only one degree of freedom. If you consider the area of the dart-board vs the area of the bullseye, the odds are much lower.
- Sharlin 7y agoNo, the GP specifically talked about area.