SCI A huge, previously undetected asteroid just came very close to Earth

H

Housecarl

On TB every waking moment
For links see article source.....
Posted for fair use.....
http://www.sciencealert.com/a-huge-previously-undetected-asteroid-just-came-very-close-to-earth

A huge, previously undetected asteroid just came very close to Earth

Everything's fine.

BEC CREW
31 AUG 2016

A 35-metre-long asteroid just came unusually close to Earth, and we barely even saw it coming.

Despite the fact that it got less than a quarter of the distance between Earth and the Moon away from us, no one even knew it existed until a day before its relatively narrow flyby.

Now, let’s not pretend this thing was ever going to hit us - the closest it got to us was no more than 100,000 km away. But how did something so big sneak up on us like that?

Detected by the International Astronomical Union’s Minor Planet Centre (MPC) - the official worldwide organisation for collecting observational data on minor planets, asteroids, and comets - the newly discovered asteroid, called 2016 QA2, swung into view on Saturday August 27.

It then made its closest approach to Earth on Sunday August 28, with the MPC tweeting that it’s estimated to be between 16 and 42 metres long, and got within 0.22 lunar distances of the surface of our planet (1 lunar distance is 384,400 km or 238,900 miles).

Minor Planet Center ý@MinorPlanetCtr

Asteroid 2016 QA2 discovered. Flyby Aug 28 at 01:24 UT. Dist: 0.23 LD (0.22 LD from Earth surface). Size: 16-52 m. http://bit.ly/2bqks7f

6:30 PM - 27 Aug 2016

28 28 Retweets
29 29 likes
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It’s not so unusual that we didn’t notice an asteroid.

NASA estimates that over 90 percent of the near-Earth objects (NEOs) larger than 1 kilometre have already been discovered, but so far only 30 percent of the 160-metre (460-foot) NEOs have been found, and less than 1 percent of the 30-metre (100-foot) NEOs have been detected.

An asteroid or comet is classified as a near-Earth object if its closest approach to the Sun is less than 1.3 astronomical units (AU), with 1 AU equalling 149,598,000 km or 92,955,887 miles.

These little space rocks are the ones that keep us on our toes, because they're simply too small for us to detect until they get close, but they're big enough to cause some real damage if they actually make an impact.

Add this to the newly discovered asteroid's weird orbit, and we've got the makings of a surprise flyby.

As Ria Misra explains over at Gizmodo, "If you look at the path of 2016 QA2 below, you can definitely see it come close to Earth for its weekend flyby - but more broadly, its elliptical orbit means that it spent a lot of time out in the further planetary regions by Mercury, Venus, and Mars."

Graphic - Created by Gizmodo using NASA JPL’s Small body database observer

So we live to see another day, and wave goodbye to another space rock.

At least the flyby gave the team at the Virtual Telescope Project something to look at - check out this awesome shot of asteroid 2016 QA2 they managed to capture as it went whizzing by:

asteroid-aug.jpg

http://www.sciencealert.com/images/2016-08/asteroid-aug.jpg
 
P

Possible Impact

TB Fanatic
NASA estimates that over 90 percent of the near-Earth objects (NEOs) larger than 1 kilometre have already been discovered, but so far only 30 percent of the 160-metre (460-foot) NEOs have been found, and less than 1 percent of the 30-metre (100-foot) NEOs have been detected.

An asteroid or comet is classified as a near-Earth object if its closest approach to the Sun is less than 1.3 astronomical units (AU), with 1 AU equalling 149,598,000 km or 92,955,887 miles.

These little space rocks are the ones that keep us on our toes, because they're simply too small for us to detect until they get close, but they're big enough to cause some real damage if they actually make an impact.
Click to expand...


:dot5: 90% is optimistic 'feel good' talk from NASA...
[FONT=arial, helvetica, sans-serif]NEO Discovery Statistics
[/FONT]
http://neo.jpl.nasa.gov/stats/

With over 90% of the near-Earth objects larger than one kilometer
already discovered, the NEO Program is now focusing on finding 90%
of the NEO population larger than 140 meters.

Many of the charts and tables below depend on diameters that
can only be roughly inferred from an asteroid's estimated absolute
magnitude (H) and an assumed reflectivity, or albedo.


The following chart shows the cumulative number of known
Near-Earth Asteroids (NEAs) versus time.

Totals are shown for NEAs of all sizes, those NEAs larger than ~140m in size,
and those larger than ~1km in size.

nea_vs_time_chart_640px.jpg


The following chart shows the current total number of known NEAs
grouped according to their estimated sizes.

The first size bin represents NEAs smaller than ~30m in diameter.
The last bin represents NEAs with diameters larger than ~1km.

nea_size_bin_chart_640px.jpg
 
V

vestige

Deceased
alchemike said:
35 meters long is hardly huge.

o)<

mike
Click to expand...

....unless it hits in your back yard.

These little space rocks are the ones that keep us on our toes, because they're simply too small for us to detect until they get close, but they're big enough to cause some real damage if they actually make an impact.
Click to expand...

Marginalizing them changes nothing.

If one the size of a VW hits in your backyard it's curtains for you. (and probably a lot of your neighbors)
 
TheSearcher

TheSearcher

Are you sure about that?
This is the number one reason to get ourselves spread around in space a bit as a species. Sure, most of these things miss the planet, but not all, and some of the bigger ones have rearranged the earthly biological landscape. We should be looking harder for these rocks and finding them earlier, working harder to find solutions to reduce their threats in some way, and get into space to preserve the species if the other two efforts fail.
 
Dennis Olson

Dennis Olson

Chief Curmudgeon
_______________
vestige said:
....unless it hits in your back yard.



Marginalizing them changes nothing.

If one the size of a VW hits in your backyard it's curtains for you. (and probably a lot of your neighbors)
Click to expand...



Well, it's also NOT an ELE event either, so why the :hof: :hof: :hof: :hof: :hof: :hof:


Some of you need to step back and take a few breaths fer gawd's sake...
 
TheSearcher

TheSearcher

Are you sure about that?
Dennis Olson said:
I'm sorry, hut "huge" and "35 meter" don't go together.

THe OP is hyperbole in the extreme.
Click to expand...


The meteor that hit Russia a few years ago was something like 20 meters, and it was locally quite destructive. I do agree that it wasn't a planet-killer, but it certainly ruined a bunch of people's day, as well as their homes and businesses. A 35-meter object is not likely to be less impactful, pun intended.



I agree that the OP was hyperbolic, but the consequences of one of these rocks hitting can be quite high, and based on recent history, also not impossible.
 
V

vestige

Deceased
The excitement is because the folks who claim to know everything about everything and everybody didn't have a clue.

A 35 meter ball may not be an ELE when it hits... but if it hit in Times Square it would play hell with rush hour traffic...

for many years.
 
packyderms_wife

packyderms_wife

Neither here nor there.
TheSearcher said:
The meteor that hit Russia a few years ago was something like 20 meters, and it was locally quite destructive. I do agree that it wasn't a planet-killer, but it certainly ruined a bunch of people's day, as well as their homes and businesses. A 35-meter object is not likely to be less impactful, pun intended.



I agree that the OP was hyperbolic, but the consequences of one of these rocks hitting can be quite high, and based on recent history, also not impossible.
Click to expand...

wasn't that a comet fragment though, it wasn't a blob of solid metal like the one in post #15
 
Countrymouse

Countrymouse

Country exile in the city
TheSearcher said:
The meteor that hit Russia a few years ago was something like 20 meters, and it was locally quite destructive. I do agree that it wasn't a planet-killer, but it certainly ruined a bunch of people's day, as well as their homes and businesses. A 35-meter object is not likely to be less impactful, pun intended.



I agree that the OP was hyperbolic, but the consequences of one of these rocks hitting can be quite high, and based on recent history, also not impossible.
Click to expand...


To those who say we can go "meh" at a 35-meter asteroid---

Another meteorite in Russia, one only twice that size (60 meters at some estimates) did this, over a 770 square-mile area:

Tunguska.png


Look up "Tunguska."

So I think we're justified in saying one HALF the size, could conceivably do HALF the damage.


Oh well, 385 square miles devastated (give or take)---no biggie, right?

https://en.wikipedia.org/wiki/Tunguska_event
 
T

tanstaafl

Has No Life - Lives on TB
For the math challenged, a 100 meter asteroid is NOT twice the size of a 50 meter asteroid. Not to mention the size in space is not generally the same as the size at impact. And not all meteorites are created equal -- there's a BIG difference in the impact a 100 meter (solid and at impact) stony meteorite would make vs. the impact the same size a 100 meter (again, solid and at impact) nickel-iron meteorite would make.
 
ersatzpanther

ersatzpanther

Senior Member
One of these days (hopefully thousands of years from now), a rather large one (multi-mile in diameter iron meter from the Oort Cloud, a shell that surrounds the entire solar system and is a hundred times as distant as the Kuiper Belt.) will hit Earth from "out of the ecliptic", i.e. from North or South pole direction. This will get near us at comet speed and is undetectable by current technology. This will be an ELE event.

Have a good day.
 
Last edited:
TheSearcher

TheSearcher

Are you sure about that?
vestige said:
The excitement is because the folks who claim to know everything about everything and everybody didn't have a clue.
Click to expand...

Who claims that? NASA? No they don't. People may have that expectation, but if anything, NASA tries to get people to understand how LITTLE we know about the universe. NASA knows a lot more than anyone else about the nature of the cosmos, but it's such a small amount of what is waiting to be known. I find that to be simultaneously fascinating and foreboding.
 
TheSearcher

TheSearcher

Are you sure about that?
packyderms_wife said:
wasn't that a comet fragment though, it wasn't a blob of solid metal like the one in post #15
Click to expand...

I think you're right about that, and in some ways that's better, and in some ways worse. The cometary bodies are lower destiny, carrying less inertia to impart at impact, so that can be better. For the worse, the lower density usually comes with fragmentation and a greatly expanded collective impact zone, instead of an impact point.

It's kind of like being asked if you want to be shot in the heart with a 357 slug, or hit with a shotgun blast to the chest in general. There's not usually a satisfactory choice there...
 
GammaRat

GammaRat

Veteran Member
In my opinion 150+ feet across IS huge.

If it's comprised mostly of Iron, It would have a VERY LARGE blast radius when it hit the ground.
 
TheSearcher

TheSearcher

Are you sure about that?
Countrymouse said:
To those who say we can go "meh" at a 35-meter asteroid---

Another meteorite in Russia, one only twice that size (60 meters at some estimates) did this, over a 770 square-mile area:

Tunguska.png


Look up "Tunguska."

So I think we're justified in saying one HALF the size, could conceivably do HALF the damage.


Oh well, 385 square miles devastated (give or take)---no biggie, right?

https://en.wikipedia.org/wiki/Tunguska_event
Click to expand...

I agree with what you are saying, though Dennis is generally correct that the OP was a news story turned into a speculative doom thing. That said, a half-sized Tunguska-esque impact isn't an global ELE, but it would be a very educational local demonstration of an ELE. The Tunguska event was massive, but only human-benign because very few, if any, humans lived there at the time. If it had struck a major city, millions would likely be dead, many more injured, and the physical devastation would have been enormous.
 
The Mountain

The Mountain

Here since the beginning
_______________
A. This is not a "huge" object as far as asteroids go. Yes, had it hit near a population center it would have made a mess, but the odds of that are quite low. Most of these things hit water, and until recently we never even noticed.

B. It's not very surprising that we didn't see this one coming. Most of the telescope coverage is in the northern hemisphere, so we have huge gaps even when everyone is deliberately looking for asteroids. Since asteroids do not generate a tail, and have low albedo levels, they're easy to miss even when you're looking hard. You're talking about spotting something that would cover less than half a football field and is essentially black against a black background at a distance of halfway to Mars.

It's a big problem in all seriousness, and one we ought as a species to get a handle on. Even though the really big ones don't swing through very often, and hit even less frequently, the cost of a strike is incalculable. Little pebbles like this one aren't much to worry about in and of themselves, but they do serve to highlight the bigger problem.
 
TheSearcher

TheSearcher

Are you sure about that?
The Mountain said:
A. This is not a "huge" object as far as asteroids go. Yes, had it hit near a population center it would have made a mess, but the odds of that are quite low. Most of these things hit water, and until recently we never even noticed.

B. It's not very surprising that we didn't see this one coming. Most of the telescope coverage is in the northern hemisphere, so we have huge gaps even when everyone is deliberately looking for asteroids. Since asteroids do not generate a tail, and have low albedo levels, they're easy to miss even when you're looking hard. You're talking about spotting something that would cover less than half a football field and is essentially black against a black background at a distance of halfway to Mars.

It's a big problem in all seriousness, and one we ought as a species to get a handle on. Even though the really big ones don't swing through very often, and hit even less frequently, the cost of a strike is incalculable. Little pebbles like this one aren't much to worry about in and of themselves, but they do serve to highlight the bigger problem.
Click to expand...

Well said.
 
H

Housecarl

On TB every waking moment
The Mountain said:
A. This is not a "huge" object as far as asteroids go. Yes, had it hit near a population center it would have made a mess, but the odds of that are quite low. Most of these things hit water, and until recently we never even noticed.

B. It's not very surprising that we didn't see this one coming. Most of the telescope coverage is in the northern hemisphere, so we have huge gaps even when everyone is deliberately looking for asteroids. Since asteroids do not generate a tail, and have low albedo levels, they're easy to miss even when you're looking hard. You're talking about spotting something that would cover less than half a football field and is essentially black against a black background at a distance of halfway to Mars.

It's a big problem in all seriousness, and one we ought as a species to get a handle on. Even though the really big ones don't swing through very often, and hit even less frequently, the cost of a strike is incalculable. Little pebbles like this one aren't much to worry about in and of themselves, but they do serve to highlight the bigger problem.
Click to expand...

TheSearcher said:
Well said.
Click to expand...

Second that....As to the article title and tone, I've just gotten back on line so bear with me on getting something a bit less "OH CRAP!!!" article wise....

Here we go....

For links see article source.....
Posted for fair use.....
http://earthsky.org/space/asteroid-2016-qa2-august-27-28-2016

Hours after discovery, asteroid swept by

By Eddie Irizarry in Space | August 28, 2016

Asteroid 2016 QA2 was twice as big as the space rock that entered over Russia in 2013, breaking windows in 6 Russian cities. It passed safely Saturday night.

2016-QA2-2.gif

http://en.es-static.us/upl/2016/08/2016-QA2-2.gif
The calculated orbit of 2016 QA2. Via JPL Small Body Database/ sciencythoughts.blogspot.com.

An asteroid safely passed by our planet on Saturday night – August 27-28, 2016 – just hours after being detected. Astronomers have labeled the space rock as asteroid 2016 QA2. The rock is estimated to be at least twice as big as the Chelyabinsk meteor that penetrated the atmosphere over Russia in February, 2013.

According to the Minor Planet Center, closest approach to Earth occurred August 28 at 01:24 UTC (9:24 p.m. EST on August 27; translate to your time zone). The asteroid has an estimated size of 111.5 feet (34 meters), although its exact dimension can range between 52-171 feet (16 to 52 meters).

The speeding space rock came considerably closer than the moon, as it passed at just 0.22 the Earth-moon distance. That’s about 52,580 miles (84,619 km) away. For comparison, the moon is located at some 239,000 miles (384,633 km) from Earth.

Asteroid 2016 QA2 was first seen by the SONEAR Observatory at Oliveira, Brazil.

Space rock 2016 QA2 appears to be an Aten asteroid, which belongs to a group of Near-Earth Asteroids (NEOs).

Using a 17-inch (43-cm) diameter telescope, Gianluca Masi, of the Virtual Telescope Project in Italy, was able to capture a sequence of images showing the space rock moving across the stars. You can see the images here : http://www.virtualtelescope.net/2016qa2_28aug2016.gif

Via Gianluca Masi/ Virtual Telescope Project
Via Gianluca Masi/ Virtual Telescope Project

Minor Planet Center ý@MinorPlanetCtr

Asteroid 2016 QA2 discovered. Flyby Aug 28 at 01:24 UT. Dist: 0.23 LD (0.22 LD from Earth surface). Size: 16-52 m. http://bit.ly/2bqks7f

6:30 PM - 27 Aug 2016
29 29 Retweets
31 31 likes
Click to expand...

Bottom line: Small asteroid 2016 QA2 passed safely on August 27-28, 2016, just hours after discovery.
 
F

FarmerJohn

Has No Life - Lives on TB
It's been pointed out that the reason that the dinosaurs are (mostly) extinct is that they didn't have a space program.
 
T

TerryK

TB Fanatic
here is the link to the earth impact database.
http://www.passc.net/EarthImpactDatabase/NorthAmerica.html

I have selected just North America, but you can select any continent or the whole world.
It lists the name, impact location, crater size, age etc of all the sizable impacts we are aware of.
It includes Chicxulub in Mexico Yucatan 65 million years ago that created a crater 150 miles wide and wiped out the dinosaurs and 70% of life on earth. Large animals didn't stand a chance.
 
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