Watch: Tiny asteroid discovered Saturday disintegrates over Africa

A boulder-sized asteroid designated 2018 LA was discovered Saturday morning, June 2, and was determined to be on a collision course with Earth, with impact just hours away. Because it was very faint, the asteroid was estimated to be only about 6 feet (2 meters) across, which is small enough that it was expected to safely disintegrate in Earth's atmosphere. Saturday's asteroid was first discovered by the NASA-funded Catalina Sky Survey, located near Tucson and operated by the University of Arizona.

Although there was not enough tracking data to make precise predictions ahead of time, a swath of possible locations was calculated stretching from Southern Africa, across the Indian Ocean, and onto New Guinea. Reports of a bright fireball above Botswana, Africa, early Saturday evening match up with the predicted trajectory for the asteroid. The asteroid entered Earth's atmosphere at the high speed of 10 miles per second (38,000 mph, or 17 kilometers per second) at about 16:44 UTC (9:44 a.m. PDT, 12:44 p.m. EDT, 6:44 p.m. local Botswana time) and disintegrated several miles above the surface, creating a bright fireball that lit up the evening sky. The event was witnessed by a number of observers and was caught on webcam video: [above video]

When it was first detected, the asteroid was nearly as far away as the Moon's orbit, although that was not initially known. The asteroid appeared as a streak in the series of time-exposure images taken by the Catalina telescope. As is the case for all asteroid-hunting projects, the data were quickly sent to the Minor Planet Center in Cambridge, Massachusetts, which calculated a preliminary trajectory indicating the possibility of an Earth impact. The data were in turn sent to the Center for Near-Earth Object Studies (CNEOS) at NASA's Jet Propulsion Laboratory in Pasadena, California, where the automated Scout system also found a high probability that the asteroid was on an impact trajectory. Automated alerts were sent out to the community of asteroid observers to obtain further observations, and to the Planetary Defense Coordination Office at NASA Headquarters in Washington. However, since the asteroid was determined to be so small and therefore harmless, no further impact alerts were issued by NASA.

phys.org, Tiny asteroid discovered Saturday disintegrates over Africa.

That is pretty impressive for a 2m asteroid! It was so small that it was not noticed until it was right on top of us. It was just a matter of hours from spotting it that it actually entered the earth's atmosphere. Over at spaceweather.com, they have the infrasound plot stating it was the "equivalent to 0.3 to 0.5 kilotons of TNT" (spaceweather.com).

Nice to see how the system works too.

Or as the Borg Queen says to Picard, "Watch your future's end".

Asteroid, maybe. Point man for an alien invasion, almost certainly.

a reply to: underwerks


It wouldn't surprise me! Attack when the earth is erupting and all.

Nice to see that the giant gun in the Russian taiga is still functional too!

a reply to: TEOTWAWKIAIFF

It's pretty impressive they can identify something as small as that heading our way from 250.000 miles away , kinda makes me feel protected.


Here's another view of it as seen from China.


One of these days something bigger will come , until then I like the smaller ones.

a reply to: gortex

The article goes on to say that the Catalina Sky Survey has caught all 3 of the earth impacting space rocks and that this was the smallest.

Yeah, smaller is better!

Nice vid!

JPL/NASA - How does NASA Spot a Near-Earth Asteroid


This was also included with the article from OP. A short video explaining how the Planetary Defense Team works.

Nerdy cool!

Good job automated software!

2 meters in dia.. just a matter of time before the 200 meter in dia comes by

impressive.

originally posted by: TEOTWAWKIAIFF
a reply to: underwerks


It wouldn't surprise me! Attack when the earth is erupting and all.

Nice to see that the giant gun in the Russian taiga is still functional too!

I'm reminded of the opening scene from Predator.

a reply to: RoScoLaz5

Most impressive. *Darth Vader voice*

a reply to: TEOTWAWKIAIFF

You guys are crazy. Three hours is barely enough notice to have to spend your last three hours miserable in traffic, especially considering that they didn't know where it was going to really be.

Jaden

a reply to: RoScoLaz5

Your post is everything good about the internet!!!!!

And those asteroids will keep on coming, is there A predetermined path already being taken by the rock of DOOOOOOM!!

That was pretty cool.
I saw one the other morning. I live out in the boondocks, It's pretty dark and quiet. It looked at first like a typical "falling/shooting" star that you see. But instead of falling like vertically way off in the distance, This shot horizontal over my head.

Well obviously not over my head or I would not have seen it. But was so cool because I could see individual sparks coming off it. And I swear I could hear it.

I watched it expecting to see an impact. I did not. I thought about starting a thread to basically ask how close something would have to be to see "sparks" and to hear it. It looked and sounded a lot like a bottle rocket. It was pretty freaking cool.

So now that I don't have to start a thread does anybody know how close this thing would have to be to hear it and see glowing fragments coming off it?

a reply to: gortex

Makes you feel protected? They can't stop something like that and a warning won't protect anyone since they cannot adequately predict it's path when it comes into the atmosphere. I do think it is nice that they can give us advanced warning so we can go outside and watch as they come in though.

Yeah, the cute little guys are cool as heck and act as looooong interval fireworks of a rudimentary nature.

Any bigger rocks would be quite a sight, too, but could be the last thing anything on that hemisphere would see.

As we've only put a measly, token effort into finding "planet killers" (sorry Catalina Sky Survey, but we all know a shack on Mt Lemmon with some stoned grad students ain't gonna cut it when the big one comes) I'm hoping our governments know we have far better 'wardens' out there watching our collective backs, as our leaders couldn't possibly be so short sighted as to not prepare for the inevitable ELE behemoth hurtling our way, right? Right?!

I'll sleep better telling myself the ancient asteroid blasters in the tundra, along with the equally possibly mythical knights of relearnt knowledge are keeping us safe from falling mountains.

a reply to: Baddogma

Don't worry!

The RKers will keep you busy while you sleep too!

One of the reasons I put spaceweather.com up there is they have a NEA plots with size and lunar distances listed. Until it is less than 1 LD do I take notice. Then I check the size.

It would be shame to be so close to so many things only to have space rock send us back to the caves.

originally posted by: gortex
Here's another view of it as seen from China.

That's a different event to the one being discussed in this thread. It occurred one or two nights before IIRC. While not impossible, it is exceptionally rare for an object to be observed entering the atmosphere from two continents.

originally posted by: tinner07
So now that I don't have to start a thread does anybody know how close this thing would have to be to hear it and see glowing fragments coming off it?

Not close at all. The simultaneous sounds (called "electrophonic" sounds) associated with meteors are due to VLF emissions interacting with the stuff around you, so they travel at the same speed as the light from the object. Sound travels considerably slower, and usually takes a minute or two to reach the observer. You should always wait and listen for distant booms/rumbles if you see a fireball.

Some links:
Global Electrophonic Fireball Survey
The American Meteor Society Fireball FAQs

Likewise, fragmentation can be observed from many tens of Km away. An event that is observed close to the observer's apparent horizon (assuming relatively flat terrain) can be up to 500 or 600 Km away, and somewhere in the region of 80-100 Km above the ground. To be close to a meteor it would have to be more or less overhead under normal circumstances.

If you were unfortunate enough to observe an object at close range which was large enough to make it down to the ground or close to it. You'd know about it. In most cases even significant sized objects don't make it down to ~20 Km altitude. At the very least there would be massive sonic booms - remember these objects are having to travel way above the speed of sound to be self-luminous (minimum speed of ~1 Km per second is required).

It's typical with meteors, especially brighter meteors and fireballs, that they are perceived as being much closer than they actually are. It's an optical illusion. Our brains simply interpret "bright" as "close", when in the case of meteors (and other lights can also have the same effect), they are usually far away.

It's very common to hear "it fell near by" when a bright fireball is widely seen, for this reason, and it can easily be shown not to be the case. In most cases, 25-500 Km is about as close are you're likely to get, and you'd be extremely fortunate to observe one at 25 Km!

a reply to: tinner07

If you check on amsmeteors.org, and look for an event with a timestamp that approximates when you saw your fireball, you may get some more information about where the fireball was located relative to your viewing location.

Depending on how many people reported the sighting, they can triangulate the location and path of the meteor.

You might also consider adding your sighting to the report. The interface is kind of fun.

-dex

Update!

Asteroid 2018 LA was detected in space eight hours before hitting Earth. It was detected by the Catalina Sky Survey, operated by the University of Arizona and sponsored by NASA as part of its Planetary Defence mission.

On Saturday, June 23, 2018, a team of experts from Botswana, South Africa, Finland and the United States of America recovered a fresh meteorite in Botswana's Central Kalahari Game Reserve (CKGR). The meteorite is one of the fragments of asteroid 2018 LA which collided with Earth on June 2, 2018 and turned into a meteor fireball that detonated over Botswana a few seconds after entering the atmosphere. The incident was witnessed by a number of spectators in Botswana and neighbouring countries and was captured on numerous security cameras.

This is the third time in history that an asteroid inbound to hit Earth was detected early and only the second time that fragments were recovered.

phys.org, July 6, 2018 - Fragment of impacting asteroid recovered in Botswana.

Remember the fireball video? Well, they did a projected dispersal area for any fragments which happened to be in the Central Kalahari Game Reserve! The article describes getting permission to enter the reserve, with guards, so they could comb the projected area. They found a piece!

There is no way to scale the size in the photo but it does not look very large. Those worried about "death by meteor" can rest a little easier! In fact, they said that any fragments would be blown by the winds which is why they had to make a projected area. That is how small any surviving pieces are.

The photo shows a black meteorite amongst twigs and earth. From a six foot boulder to wind blown pebbles... well, I guess it didn't "explode in the atmosphere" as they expected.

They will continue searching until they cover the likely impact area.