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insufficientmind t1_jdnsk2e wrote

NASA also says this:

"Newly-discovered asteroid 2023 DZ2 will sail safely past Earth today. Asteroids pass our planet safely all the time, but a close approach by one of this size (140–310 ft, or 43–95 m) happens only about once per decade. (There is no known threat for at least the next 100 years.)"

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sithelephant t1_jdnv7hw wrote

A fun number to remember is that a circle with the diameter of the lunar orbit is very close to 1/64th the radius of earth. This means the earth covers about 1/4000th of the area which an asteroid has to pass through if it gets within the lunar distance.

So, if it goes past at 1 lunar distance, you have a 1/4000 chance of a hit (if it was random). 1/4 lunar distance, 16/4000 (1/250).

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za419 t1_jdo52fp wrote

We'd have to do some orbital mechanics on this one. Most things in the solar system are roughly coplanar on the ecliptic, so the real shape is probably a section of the sphere a few degrees wide.

Or we could probably just guess and multiply the space available by a substantial number, because even that section is going to be pretty tall compared to the Earth. Space is big.

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reedef t1_jdo52pd wrote

You also have to account for the fact that the earth itself attracts asteroids even if they're not heading 100% towards the earth, though I'm not sure how large of an effect that is at interplanetary speeds

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Throwawaycuzawkward t1_jdo82my wrote

Space: We live in it. Some stuff happens.

It's cool enough to spend your whole life studying it, and if you're lucky it won't kill you.

Also time and dinosaurs. SCIENCE.

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kimilil t1_jdo88fq wrote

I like how on Reddit only 1/6th of the globe mattered.

And how just 4 americans can censor me from reaching the rest 5/6th of the world.

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Nowbob t1_jdo9nhq wrote

>a circle with the diameter of the lunar orbit is very close to 1/64th the radius of earth

???

What am I missing here? The lunar orbit is MUUUUUCH larger than the radius of the earth isn't it?

Wouldn't the lunar orbit being 1/64 the radius of the earth mean that the moon is whizzing past just barely overhead?

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Zeconation t1_jdoa3nu wrote

Suddenly I feel concerned.

Just kidding.

Lets die already.

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aurumae t1_jdoahwd wrote

“Half the distance to the moon” makes it seem like this is a very close approach, and in relative terms it is.

But the distance between Earth and the moon is still mind-bogglingly huge. So big, that you could fit all the other planets in the solar system end-to-end between Earth and the moon and still have space to spare

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dreamchains t1_jdoav8e wrote

Not quite, it depends on the orientation of the planets (pole to pole/side to side) and the position of the moon. But that makes it even more interesting to me how close those numbers happen to be.

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dreamchains t1_jdob9a5 wrote

Appreciate not being misleading with the title and calling it a "near miss" or whatever

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loosebolts t1_jdocf0f wrote

How long have we got? 3:51pm EDT is 7:31pm GMT so was this 3 hours ago so obviously it passed by already, or have I got my time conversions incorrect?

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Rhaedas t1_jdochbw wrote

We'll never find them all if you include ones that are perturbed from the outer parts of the system to fall inward. And we'll definitely not find ones in time without a better search and detection program. Relying on amateur astronomers and rare free time at the major telescopes, both only done at night, it pretty limited and why so many near passes are discovered after they do pass and not before.

I do wonder if there's any validity in Asimov's prologue for Rama, where Spaceguard uses a nuclear blast (neutron?) to generate a radar image of the system to map just about everything. Of course Rama was conveniently not in this scan.

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censored_username t1_jdocx9y wrote

>This asteroid is about 100X smaller than the one that killed the dinosaurs

Additional note, it is 100x smaller in linear size, which puts it around the order of a million times lighter than the chicxulub asteroid.

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Monnok t1_jdodiq3 wrote

Your Earth-volume : lunar-orbit-volume ratio works for the likelihood of finding the asteroid inside or outside of the Earth at any given moment.

But we can assume the object has an entire path of moments passing straight through on [basically] a line. An asteroid “looking ahead” directly at the round perimeter of the Earth might briefly occupy some point “in front” of the Earth before collision… but that’s still a collision path. And it’s never gonna get to any points on the other side. What it “sees” just is a flat disc in a flat disc. It’s either heading through the empty part or not.

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nighthawke75 t1_jdoeqzb wrote

Just within range of Dr Nesbitt's defense array.

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n21lv t1_jdog2rl wrote

Funny how OP decided to be helpful and provide an alternative timestamp (the one in parenthesis), but as a true American, chose another US/Canada-specific time zone instead of something like UTC :)

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MinniMemes t1_jdolves wrote

The operative word is could, as in, given the correct positioning, you COULD make this occur. It’s not saying “you will make this occur, given any possible positioning/rotation.”

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jeffinbville t1_jdonahs wrote

"(There is no known threat for at least the next 100 years.)"

Good to know!

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Guses t1_jdonewp wrote

You guys know about Tunguska? It was thought to be only 56-foot-wide (50 m) asteroid. It flattened trees over 830 square miles when it burst in the air. That's flattening an entire area 28 miles by 28 miles. And that's on the lower end of the range for DZ2.

Could easily kill millions of people in an instant.

Kinda scary that there are objects like this that are floating around and that we only notice at the last minute.

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Guses t1_jdonwwo wrote

>There is still no known threat

Known being the key word. We didn't know about this thing until it was on top of us.

Risks are low but the outcome could be really really bad.

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DoctorProfessorTaco t1_jdornit wrote

I think you mean 64x the radius of the Earth, not 1/64 the radius.

The radius of the Earth is 6,378km, I don’t think you mean that a circle with the diameter of the lunar orbit is 1/64 of that, or about 100km.

Additionally, even if you mean 64x larger, it’s still not quite correct. The average diameter of the lunar orbit is 768,000km. 1/64 of that is 12,000km.

What you probably meant to say was the average radius of the lunar orbit is approximately equal to 64x the radius of Earth, or that the radius of Earth is about 1/64 the average radius of the lunar orbit.

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DasbootTX t1_jdos8m5 wrote

Well message from the future. Nothing happened

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dreamchains t1_jdovhv9 wrote

Notice how you had to clarify that you COULD do it, but only given the correct positioning? That was literally the exact point of my comment lmao. I was just trying to add to a cool fact, not argue semantics.

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razgoull t1_jdoyqep wrote

We had an earthquake in my town exactly at the same time it passed close to earth. Strange huh 🤔

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reedef t1_jdp1shr wrote

So I started researching and Wikipedia actually has a calculation on this and for an asteroid with hyperbolic excess velocity of 12.5 km/s the effective increase of the cross sectional impact area is 80%. Not x10 or anything but not insignificant either.

The impact is going to be larger than that for objects that approach the earth from nearby orbits.

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d_barbz t1_jdp286p wrote

He didn't need to clarify it until you misunderstood it.

If you wanted to add to a cool fact your sentence would have been better off starting with something along the lines of "And", "Also" or even "However" rather than something that's attempting to be contradictory like "Not quite".

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r0ckH0pper t1_jdp8dq8 wrote

Propaganda and lies! This is BS. That DZ2 was discovered less than a month ago o Feb 27, 2023. To believe NASA reassurance is folly. They can't have ANY certainty of the next 100 (Earth) years when they can't see the flying bricks even a month before they could collide. There may be a similar one just 5 weeks away from destroying a city that is yet to be seen by humans. Sure, the odds are low and I'm not worried. But, don't believe if a word of that bull crap from NASA ...

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dreamchains t1_jdpbeoa wrote

You clearly don't understand what "not quite" means, so not sure why you're being so pedantic. It's not contradicting anything. It's saying his comment was "not completely or entirely" (definition straight from google) true. Really don't understand why you guys feel the need to get so defensive on behalf of someone I wasn't even attacking.

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portmantuwed t1_jdpig9p wrote

250k miles seems pretty accessible to me and not "mind-bogglingly huge". this sub regularly posts about jwst newest galaxy thats 13 billion light years away. a day or two ago had a long running joke about the distance between castor and pollux being like some quadrillion tennis courts or whatever

most americans will drive over 250k miles in their lifetime. if you've driven coast to coast you can imagine doing it 99 more times and how far that is. its so much more imaginable than a light year

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jojomott t1_jdpm7p4 wrote

^(i am not a math guy, but I think NASA just said there is a 1 in 10 chance that this asteroid is going to hit earth.)

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aurumae t1_jdppk9t wrote

My point was to illustrate that even though the moon is the closest thing to us in space the distances are still vast compared to the sizes of the planets themselves. The Earth and moon are often depicted as being practically on top of each other, but the distance between them is two orders of magnitude greater than the size of either body. Like I said the distance is so big that you could fit all the planets in the solar system between the Earth and the moon (though as someone pointed out, only at apogee). Of course, since the moon is the closest thing to us, other distances are going to be much more impressive, but the fact that you could drop a great big giant thing like Jupiter in between the Earth and the moon and for it not even to be a tight fit I found really helped me to get a sense of the distance.

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danielravennest t1_jdres22 wrote

Unknown. This asteroid was only discovered a month ago. To make long-term predictions you need to know the current orbit precisely. It hasn't been watched long enough to do that yet. The close pass will help. They can use radar to get some very good measurements

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Rhaedas t1_jdrlzvf wrote

Both impressive and the results of Atlas since operation shows it's doing a great job. A space-based telescope system would be able to do so much more, especially since it wouldn't have the limitations of only scanning the night sky that a ground one does. A key point - any impactor that is in a orbit similar to Earth's is that the last years of its path will be from the Sun side of the planet. The sooner we see anything and can calculate mass and vectors the sooner we can do any action that we might be able to do. Another key point - to be able to do anything like deflection we have to get to the object first long before its arrival, so knowing years in advance is crucial.

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MinniMemes t1_jdsmtcj wrote

The pedantry started with your comment. “Not quite” starts with a negation. There’s no need to negate something that was already true. You can clarify without negating. In fact, it’s much more fun that way. Share first, rather than using language that is ‘gatekeep-y’.

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