Question Asteroid Apophis

[Husno122]

Will asteroid Apophis impact on earth later upcoming month octber 2020 or it will be safely flyby the earth??? Hw much we r safe frm this asteroids???

 

[COLGeek]

I think we'll be okay.

99942 Apophis - Wikipedia

en.wikipedia.org

 

[StarShipTrooper]

Apophis is due to pass by earth and then be on its way around the sun in 2029/2030. It will come back in 2036 and is expected to plummet into the Pacific Ocean. Hawaii will be a devastating loss along with extensive damage to the west coast of the United States.

So says Neil deGrass Tyson in his book;

- Death by Black Hole; pages 261-262

Supposedly, everybody who knows something about this isn't saying much.

 

[COLGeek]

Apophis is due to pass by earth and then be on its way around the sun in 2029/2030. It will come back in 2036 and is expected to plummet into the Pacific Ocean. Hawaii will be a devastating loss along with extensive damage to the west coast of the United States.

So says Neil deGrass Tyson in his book;

- Death by Black Hole; pages 261-262

Supposedly, everybody who knows something about this isn't saying much.

Better pack your bags now then!

 

[Wolfshadw]

Last time I checked, there was a 1 in X chance ("X" being a very large number) that Apophis would pass though the necessary "key hole" that would alter it's path in such a way that it would impact Earth on a later pass.

-Wolf sends

 

[Catastrophe]

What concerns me most is not the thousands or tens of thousands of known objects (do you know how many NEOs there are?) but those we do not know about. Many of these are of low albedo and, when coming 'out of the Sun' stand zero chance of being seen in time. I remember around 1992 or 1994 (IIRC) there was one close miss, then the same day there was a total unknown (out of the Sun) which was not seen until it had passed us.

After the Late Heavy Bombardment we feel, rightly or wrongly, that we are comparatively secure from Theia size impact. However, there are extreme numbers of asteroids and comets (and the new category of in-betweens) in the outer Solar System. If large numbers of these were dislodged there is a remote possibility of impact eventually. Beyond a certain size there is nothing we can do to guard against catastrophic impact.

And this:
"alter it's path in such a way that it would impact Earth on a later pass."
can happen to the ones we 'know to be safe'.

 

[Ken Fabian]

The more Near Earth Objects that are identified and their orbits known, the more that can be eliminated from lists of potential threats; those that do show potential for collision with Earth will be watched for more closely. Consideration of what kinds of pre-emptive actions can be developed is ongoing, but right now there aren't any that are viable.

I think the NASA Near Earth Object Observation Program aimed to identify 90% of those above 140m diameter with orbits that cross Earth's by this year (2020). Not that they ignore those smaller than that, but that the larger ones represent the greater threat and trigger threat notifications - not that anything can be done, yet.. Observation will continue and will improve in effectiveness; it may never get to 100% but it may edge close to it.

I don't know but expect the largest, even with low albedo, to be amongst the easiest for this program to find.

As for the very long orbit objects or interstellar ones, that have no known prior passes to deduce any orbit from - these are uncommon enough to be a much less likely danger than the NEO's orbiting within the solar system, but will represent a far greater challenge to find and track in a timely manner.

 

[Catastrophe]

I am not convinced. See #6.

At least I think the virus will get me before the NEO.
Better still - neither

 

[Ken Fabian]

I am not convinced. See #6.

At least I think the virus will get me before the NEO.
Better still - neither

The likelihood of a big one happening in our lifetimes is very small. Not zero, but small. We've winged it for the entire existence of homo sapiens as a species so far, so I'm not losing sleep over it.

It is a good and worthy long term ambition for a healthy, wealthy, well governed global civilisation to develop an effective meteor defense. I think establishing that enduring healthy wealthy good governance is the essential first step to achieving something as ambitious as that; meteor defense that doesn't function over thousands of years isn't going to alter the odds much.

 

[Helio]

Apophis is due to pass by earth and then be on its way around the sun in 2029/2030. It will come back in 2036 and is expected to plummet into the Pacific Ocean. Hawaii will be a devastating loss along with extensive damage to the west coast of the United States.

So says Neil deGrass Tyson in his book;

- Death by Black Hole; pages 261-262

Supposedly, everybody who knows something about this isn't saying much.

Did he really say that?
More recently, from here he said, “We know it won’t hit Earth, we know it will be closer than the orbiting satellites." [I question why he is expressing confidence by using the work "know".]

The article also states, "But a 2036 impact has since been deemed almost impossible with scientists instead eyeing the year 2068 with a tiny one in 150,000 chance of collision."

If I understand it, the important test will be whether or not it passes through the "keyhole" region that will serve to guide it more toward the Earth in the future than not.

Its orbit will be monitored as it bobs and weaves, even if slightly, due to planetary perturbations, so time is required to get the risk factors right.

There are sites that shows the current impact hazard risks.... JPL site. The Torino scale (last column) gives a 2D hazard for the overall risk. It combines both the probability for an impact with the amount of potential damage it could do due to its kinetic energy (mass and speed).

 

[Helio]

What concerns me most is not the thousands or tens of thousands of known objects (do you know how many NEOs there are?) but those we do not know about. Many of these are of low albedo and, when coming 'out of the Sun' stand zero chance of being seen in time. I remember around 1992 or 1994 (IIRC) there was one close miss, then the same day there was a total unknown (out of the Sun) which was not seen until it had passed us.

Yes, and a few years ago there were two that zipped by unannounced at almost the same hour, IIRC. They weren't together, surprisingly, because they came from different directions.

 

[Helio]

As for the very long orbit objects or interstellar ones, that have no known prior passes to deduce any orbit from - these are uncommon enough to be a much less likely danger than the NEO's orbiting within the solar system, but will represent a far greater challenge to find and track in a timely manner.

We do get a break from excessive risks from these since they aren't likely approaching us from along the ecliptic plane.

 

[Helio]

I am not convinced. See #6.

At least I think the virus will get me before the NEO.
Better still - neither

I was surprised to learn that bio hazards are also two dimensional - CFR and Ro, but this isn't a Covid thread. I learned about it because I asked a doctor if there was something similar to the Torino scale.

 

[Catastrophe]

Yes, and a few years ago there were two that zipped by unannounced at almost the same hour, IIRC. They weren't together, surprisingly, because they came from different directions.

Yes, and a few years ago there were two that zipped by unannounced at almost the same hour, IIRC. They weren't together, surprisingly, because they came from different directions.
I think we are talking about the same two. I'd guess around 1992-4.

 

[Catastrophe]

Are you from USA? I only guessed from one item of spelling, but your use of commas is very educated English. I have written quite a lot btw.

Oooops. Just reviewed my 'letter' to you which covered quite a lot of that.

 

[Helio]

Yes, and a few years ago there were two that zipped by unannounced at almost the same hour, IIRC. They weren't together, surprisingly, because they came from different directions.
I think we are talking about the same two. I'd guess around 1992-4.

There have been pairs since. Here is an article of two passing us in 2010 and within about 12 hours of each other. But I think the one I recall was more recent still.

 

[Ken Fabian]

Regionally catastrophic impacts are 1 in 10,000 year events, globally catastrophic are 1 in 1,000,000 year events; most NEO's miss. One of the former could induce a major global program to develop meteor defense - but it could spend the next few thousand years not encountering any that size. One of the latter would end all attempts to develop a meteor defense, which would be the point. It is not no risk but it is not an urgent risk.

Developing and entrenching a lasting civilisation that can do meteor defense over very long time scales - longer than any civilisations have ever lasted - is essential to making meteor defense effective. If we don't achieve that we won't get the meteor defense.

Given there are no real commercial opportunities in space beyond those that service Earth based needs, meteor defense would be one of the most compelling non-commercial, taxpayer funded large scale activities we can justifiably undertake in space but it is still a multi-generational one with - by the odds - strong likelihood of being unneeded within the lifetimes of any person now living.

 

[Helio]

Developing and entrenching a lasting civilisation that can do meteor defense over very long time scales - longer than any civilisations have ever lasted - is essential to making meteor defense effective. If we don't achieve that we won't get the meteor defense.

One clever argument for a defense is that the dinosaurs had none.

 

[Catastrophe]

A couple of facts about asteroids, which happen to be my speciality.
The worst, in terms of impact frequency, is over - with the Late Heavy Bombardment. But there is no reason for complacency. If you want to know about chance or odds, ask someone who has won the lottery - or those that haven't. "I never thought it would happen to me".
If your only concern is this generation, the odds are with you. Whoever thought we would be hit by coronavirus? Will the human race survive it? Will it mutate?

If you are interested, stars and other bodies do move around in our galaxy. Just recently two objects Oumuamua and Borisov arrived from outside our Solar System. Check it out. There are millions, possibly billions, or lumps of rock far out in the SS. Some things are happening which could bring them closer to our star.

The second point is that there is a myth that we can just shoot 'em down, nuke 'em, - Hey no problem. This is cloud cuckoo land. First of all, most of these objects travel at horrendous speeds. If we detect them years in advance, we can send something to break them into smaller pieces, destroy them, alter their course. All true if we spot them in time. Only a decade or two ago (see above) two bodies passed close by in one day. One we did not know of until after it has passed us. Just look at the speed. From Wiki:

QUOTE
When a meteoroid, comet, or asteroid enters Earth's atmosphere at a speed typically in excess of 20 km/s (72,000 km/h; 45,000 mph), aerodynamic heating of that object produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake.
QUOTE

Imagine trying to 'neutralise' something coming towards us at 45,000 mph. You have to get to it, arrange your little bomb or whatever, and hope it works. In some cases it will (hopefully). It may be that you can break it up. Just make sure that not one of the pieces is not large enough to destroy us. Maybe the bits are small enough to destroy only a few 'insignificant' places like London, Los Angeles and Moscow. Hurrah! It didn't touch Brisbane, Montreal and Johannesburg.

We are told, and we believe, that research is ongoing. We have to be able to detect a large object of low albedo (difficult to see) coming "out of the Sun". Out of our blind spot and nearly invisible. There is much more to be said, but that is enough for now. The dinosaurs did not have any defence. We don't have much more.

Keep safe

 

[AsteroidAware]

Most of the concern focuses on the year 2029, where Apophis is expected to make a close approach

Check out the estimated 3D orbit here: In-browser 3D view of Apophis orbit