A Small Asteroid Buzzed Earth Wednesday, But Everything's Cool

An anonymous reader writes: If the Earth were a person, it might have felt a sudden wind rustling its hair when a small asteroid whizzed past the planet on Wednesday. The asteroid, saddled with the name 2016 RB1, is a new discovery. Astronomers just noticed it on September 5 thanks to the keen eye of a telescope from the Catalina Sky Survey in Tucson, Arizona. What makes 2016 RB1 so sneaky is its small size. It's only about 25 to 50 feet (7 to 16 meters) in diameter. It passed within just 25,000 miles (40,000 kilometers) of Earth, which NASA helpfully translates into 1/10th the distance from Earth to the moon. In terms of the massive size of the galaxy, that qualifies as a relatively close shave. An animated GIF of the flyby shows a tiny white dot moving against a grainy space background. The asteroid's trajectory kept it well out of the way of any satellites, and the planet was never in any danger.

Wooshdot

[Ann O'Nymous-Coward]

subject says it all

Re:

[coolmoe2]

Well this one was only slightly larger at 20 Meters.
https://en.wikipedia.org/wiki/... [wikipedia.org]
So yeah it might have done some significant damage to a city but not a planet killer.
Your welcome

Re:

[BoogieChile]

I found the relative velocity [nasa.gov] through the JPL small body database - a very slow 8 km/sec. Looking at the orbital diagram, it was more like the Earth passing the asteroid rather than the other way around!

Purdue's impact calculator has it at a 51 kiloton explosion, versus 541 kilotons [ic.ac.uk] for a projectile the size of the Chelyabinsk meteorite

Now who's welcome?

Re:

[As_I_Please]

This asteroid is about half the diameter of the Chelyabinsk meteor [wikipedia.org] that landed in Russia, so it would probably have similar, if smaller, effects depending on its elevation and proximity to cities when it exploded/impacted Earth.

Re:

[dreamchaser]

There are other variables to take into account such as the objects composition/density, it's velocity, and the angle that it hits at.

Re:

[Falos]

A doubled diameter is probably significant. I'm no physicist, but I think if volume's the key value it's a cubed effect, squared if it's mass. Though framing it like that (if valid) is probably oversimplified.

Sister post suggests some likely relevant factors, but I think we're overlooking proximity to civilization, a fluke of Chelyabinsk is my understanding. Earth won't notice a 20-meter in the ocean.

Re:

[Falos]

Are you going to contradict "significant"? If not you've quibbled the inconsequential, by definition.

In fact, your emphasis is supporting my claim. After downvoting it. I guess you managed to contradict something.

Re:

[Anonymous Cow Ward]

The AC was saying that both mass and volume would be a cubed effect, not cubed for volume and squared for mass.

Re:

[Applehu Akbar]

50 feet is a Chelyabink-sized asteroid. Had it been a direct hit on the city, it could have killed a million people.

That's close, in space terms

[argStyopa]

25000 miles sounds like a lot, but all the geo-stationary satellites (50+) are just about that high at about 22000 mi.

Re:

[bill_mcgonigle]

25000 miles sounds like a lot, but all the geo-stationary satellites (50+) are just about that high at about 22000 mi.

So a missed opportunity to put a big rock into a parking orbit for mining. I wonder what the delta-V is on those bad boys.

Re:

[ShanghaiBill]

So a missed opportunity to put a big rock into a parking orbit for mining. I wonder what the delta-V is on those bad boys.

Here's how to do it: Put some ion thrusters on the asteroid a few month ahead of time, and then alter the trajectory just enough so that it skims through the upper atmosphere. The friction will slow it down enough to convert the trajectory from a hyperbola to an eccentric elliptical orbit. Then use thrusters to slowly nudge it into a stable circular orbit.

In addition to mining, it can be used as a counterweight for a space elevator.

Re:

[RockDoctor]

In addition to mining, it can be used as a counterweight for a space elevator.

But we need to mine Great A'tuin to make the unobtanium for the space elevator.

Re:

[lucien86]

If they had a couple of years warning it would make a perfect target for mining - relatively small mas, close proximity, nice low delta V..

Re:

[cwsumner]

If they had a couple of years warning it would make a perfect target for mining - relatively small mas, close proximity, nice low delta V..

Don't worry, if it was passing that slow it will be back later, we can get it then.
If it doesn't hit us then...

Re:

[RockDoctor]

20-odd metres across is hardly "big".

Useful, but not a dinosaur killer. It's comparable in size to the Chelyabinsk window-shattering meteorite of a couple of years ago.

Re:

[martinfb]

25 to 50 ft diameter is not a worthy candidate for the millions it'd take to just get to it, let alone mine it!

And, what about the possibility of introducing unwanted organisms to our biosphere?

Re:

[pr0fessor]

so it missed them by about 3000 miles a little more than the width of the United States... if you drove about 8 hours a day approximately 500 miles it would take almost 6 days to cross. Sounds like a fun trip.

Re:

[glenebob]

That sounds like a horrible trip. There aren't any gas stations out there.

Re:

[David_Hart]

That sounds like a horrible trip. There aren't any gas stations out there.

Who needs gas, after all, a Tesla will make it... right.... a quick stop to solar charge it for a week (250W panel) and you are on your way again...

Re: That's close, in space terms

[cthulhu11]

Thank you for beating me to that. I cringe when someone uses the plural as singular. cf alga and algae

Re:

[I4ko]

That's not close. It is about the Earth circumference at the equator. Anything farther out and the earth's diameter is too far out.

A more useful measurement

[Alain Williams]

Is that it passed at 6.3 earth radii. If earth was a standard football (radius 4.5 inches/11.5 cm) it passed 28 inches (72 cm) away. Comfortably safe.

Re:

[Alain Williams]

I am a Brit, so yes: I mean what you call soccer, there are standard sizes [football-bible.com]. I have no idea how big an American football is.

Re:

[LynnwoodRooster]

If you could put it into Libraries of Congress we'd be able to follow along...

Re:

[Anonymous Coward]

He meant football field, not american handegg field.

Re:

[Coren22]

You do realize that all modern sports that aren't done on horseback could be named football, right? Foot referred to the sport being played on foot.

Re:

[Coren22]

Thank you for giving examples that aren't called football since they aren't played on foot, or don't involve balls...

I am unsure how any of those are counter examples of sports that could be called football as they are played on foot.

Re:

[Coren22]

Yeah, it looks like there is an idiot here, but that isn't the person behind my keyboard.

Intentionally misunderstanding what I am saying doesn't make me an idiot, but thank you for playing.

Just a little bit lower, please

[Tablizer]

a sudden wind rustling its hair when a small asteroid whizzed past the planet on Wednesday

Explains Trumps' hair.

Re:

[Tablizer]

It's a statement on grooming, not politics.

Re:

[sjames]

That was no asteroid. It was probably a shoe.

Trajectory

[QuietLagoon]

...The asteroid's trajectory kept it well out of the way of any satellites...

Fortunately, the trajectory took the rock to the south of Earth where there are very few satellites. If the rock had passed by at that same distance on the equatorial plane (where the geosynchronous satellites reside at 25,000 miles), many, many people would have lost a lot of sleep.

Re:

[QuietLagoon]

Speaking of trajectory, wouldn't passing so close to earth have altered it?

Yes. http://www.spaceweather.com/ar... [spaceweather.com] "...After it buzzed Earth, the space rock turned and headed for the Moon, executing a wider flyby of 179,000 miles on Sept. 8th. Researchers say 2016 RB1 is ~50 ft in diameter, about the size of a grey whale. ..."

Re:

[balbeir]

Well that's much bigger than a bowl of petunias. And we missed a chance to become good friends.

Re:

[suutar]

geosync is 22,300 miles, not 25k... do they put satellites at 25 and just have them thrust to stay in position?

Re:

[QuietLagoon]

...geosync is 22,300 miles, not 25k..

thx for the correction.

Thanks for telling me AFTER the fact

[mi]

... but everything's cool

I for one am grateful for learning about this after it was all over.

Astronomers just noticed it on September 5

Heavens, my pretty little head would've been worried for three days, had it been publicized then...

Nothing to see here, move along

[TheRealHocusLocus]

When a near-miss asteroid of any size is spotted with only three day's notice, it's probably not a good idea for them to say that "The planet was never in any danger."

Unless they want everyone to just shrug it off and go about our normal business while we wait to die in a sudden 'KT' fiery maelstrom.

Do they?

Re:

[michelcolman]

Yeah, they probably would have spotted it at least two weeks ago in that case.

Re:

[HiThere]

Sorry, but that's NOT certain. They estimate that they've cataloged MOST dangerous asteroids, but dangerous asteroids have previously only been detected on approach, and not because they were small.

IIRC, the last time I checked the list the estimated that they had cataloged over 99% of all earth-crossing asteroids. But they didn't provided even an estimated level of certainty. And collisions can, at any time, cause an asteroid to alter it's orbit. And they aren't checked that frequently.

So certainty is

Re:

[HiThere]

I think you misunderstand things. IIUC, *an* asteroid will almost never collide with another, but asteroids collide all the time. It's the birthday paradox again.

OTOH, changing the orbit from low eccentricity to an earth-crosser is a major encounter, and would almost never happen...but a slight orbital change that IS reasonable could set things up so that resonance with various planets could amplify the orbital change over time. Changing it into an earth-crosser is, of course, still wildly improbable. W

Preposterous comparison

[OneHundredAndTen]

In terms of the massive size of the galaxy, the closest distance of this rock to Earth and the distance from Pluto to the Sun are pretty much the same.

The planet is NEVER in any danger!

[Geste]

The planet is FINE.

Re:

[R3d M3rcury]

"...the people are fucked"
--George Carlin

Re:

[account_deleted]

Comment removed based on user account deletion

Re:

[theurge14]

The Chelyabinsk meteor from 2013 was about 20 meters in diameter, this one says 7-16 meters.

Re:

[account_deleted]

Comment removed based on user account deletion

Re:

[R3d M3rcury]

...and can you express it in Libraries of Congress?

An anonymous reader writes? Wrong!!!eleventy

[Anonymous Coward]

An anonymous reader didn't write that -- A freelance C|NET tech writer by the name of Amanda Kooser wrote that. In fact, that Slashdot summary was basically a copy/paste of her entire C|NET article.

If anything it should say "An anonymous reader informed Slashdot of an article on C|NET written by Amanda Kooser which states" and then include a summary of her article and NOT her entire article.

Re:

[RockDoctor]

That's too much like hard work for most ACs. And most "journalists".

Scout ship?

[Zoxed]

Sounds more like a stealth scout ship to me!

Re:

[stealth_finger]

Your explanation for anything slightly peculiar is aliens, isn't it? You lose your keys, it's aliens. A picture falls off the wall, it's aliens. That time we used up a whole bog roll in a day, you thought that was aliens as well.