NASA Asteroid Blunder --- AKA --- DOOOooooooom PORN!

originally posted by: datguy
a reply to: Arbitrageur

the quoted comment is also not in regards to Dimorphos or Didymos but rather the "debris" that is the topic of the article.

From the same article, second to last paragraph,

“If we follow the boulders in future Hubble observations, we may have enough data to pin down the boulders’ precise trajectories,” Jewitt said.“And then we’ll see in which directions they were launched from the surface and figure out exactly how they were ejected.”

Also bolded for emphasis

Well there is obviously some kind of misunderstanding here. You don't have to know precise trajectories to know that they do not pose a danger to the earth and the article specifically included the boulders not posing a danger to the Earth.

Fortunately, neither Dimorphos nor the boulder swarm have ever posed any danger to Earth.

See it doesn't say "neither Dimorphos or Didymos", it says "neither Dimorphos nor the boulder swarm have ever posed any danger to Earth." We don't need precise trajectories to know that, when approximate trajectories can suffice to draw that conclusion.

You really should have paid a lot more attention to the word "precise" because that's the biggest clue to what is missing in your understanding.

Saying we don't know a "precise trajectory" is a vastly different statement than we have no idea of the trajectory as your OP seems to suggest, I hope you understand that or can figure it out!

"If we follow the boulders in future Hubble observations, then we may have enough data to pin down the boulders' precise trajectories. " That is not NASA saying they have no idea where these things are going as you claim. They are saying they don't know precise trajectories! The use of the word "precise" even implies they DO have some idea where they are going, just not precisely.

originally posted by: Arbitrageur

You really should have paid a lot more attention to the word "precise" because that's the biggest clue to what is missing in your understanding.

Saying we don't know a "precise trajectory" is a vastly different statement than we have no idea of the trajectory as your OP seems to suggest, I hope you understand that or can figure it out!

Oh im so sorry Mr. Von Braun, if you would be so kind as to show me this "precise" information to ease my troubled mind.

You see when a scientist states "If we follow the boulders in future Hubble observations, then we may have enough data to pin down the boulders' precise trajectories." I assume they don't know the trajectories

Not sure how i could make such a silly assumption...I think its the "IF" and "MAY" terms that were used, to be precise.

"Here we are, almost 1 year later and we are not only learning more about the "planetary defence" impact missions affects on the Dimorphos asteroid but we are learning of its seemingly "unintended" effects"

Again the things done by man comes back to haunt us. Where was the damn oversite that says...WOuld'nt shooting that this just make a bunch of smaller things that will still one day, probably hit us?!?!
Every time we try to make things better fore oversevles, this kind of thing happens

It does beg the question that maybe that's why Trump brought "the space force" out of the black world, huh? reply to: datguy

originally posted by: datguy
You see when a scientist states "If we follow the boulders in future Hubble observations, then we may have enough data to pin down the boulders' precise trajectories." I assume they don't know the trajectories

Not sure how i could make such a silly assumption...I think its the "IF" and "MAY" terms that were used, to be precise.

It does seem like a silly assumption since as I already mentioned, the article said neither the asteroid nor the released boulders pose a threat to Earth, so how could they make that statement if they had no idea of the trajectories as your silly assumption claimed?

Planetary defense test deflected an asteroid but unleashed a boulder swarm

None of the boulders is on a course to hit Earth, but if rubble from a future asteroid deflection were to reach our planet, Jewitt said, they’d hit at the same speed the asteroid was traveling — fast enough to cause tremendous damage.

The approximate trajectories of the boulders deviate from the main trajectory of Dimorphos, but not by a lot, according to this paper:
The Dimorphos Boulder Swarm

Measurements of 37 boulders show a mean sky-plane velocity dispersion of 0.30+/-0.03 m/s, only slightly larger than the 0.24 m/s gravitational escape velocity from the Didymos/Dimorphos binary system.

So that statement tells us that they have measured the velocity of the boulders relative to the Didymos/Dimorphos to calculate the mean sky-plane velocity dispersion. It's totally incorrect to say they "have no idea" of the trajectories, just because they don't know them precisely.

a reply to: Arbitrageur

how can they make the claim that there is no threat if they clearly do not know the trajectories?
again i didnt say it i only quoted the article which quoted the scientist.

Velocity does not indicate trajectory, it is only one factor when calculating

originally posted by: datguy
a reply to: Arbitrageur

how can they make the claim that there is no threat if they clearly do not know the trajectories?

You seem to be thinking in a binary fashion, that an orbit is known, or unknown. That's not how it works in reality.

The way it works when discovering new asteroids is that a few observations can give an estimate of the trajectory, and an uncertainty to that trajectory can also be calculated. So that's a different situation than saying "we have no idea" where it's going, we have an idea based on early measurements and calculations, but how good depends on how big the uncertainty is, based on a number of factors. Then we don't suddenly "know the precise trajectory", what usually happens is that additional observations are made over time and the additional observations continuously improve the accuracy of the trajectory, and reduce the error range for the trajectory, so we get more and more confident of the trajectory over time and with additional measurements. This explains how that works, the process of continually improving the trajectory estimates has been automated for many objects and so the precision of those orbital calculations may increase frequently:

Survey and Detection of Near-Earth Objects
Note: Dimorphos is not a Near Earth Object (NEO) but some of the concepts of calculating orbital trajectories apply whether the object comes near Earth or not, it's just that we are more interested in the objects which come near to the Earth because of the potential risk they pose. So note how quickly initial orbit calculations of newly discovered objects can be made. The Catalina Sky survey for example can sometimes make an initial orbit estimate with a follow up observation the same night the object is discovered:

Catalina Sky Survey

Of the three search programs currently in operation, the CSS discovers NEOs at the highest rate...same-night follow-up on a newly discovered object can usually be accomplished, facilitating the rapid determination of its orbit and thus an evaluation of the hazard posed by the object.

But the same-night follow up and rapid determination of the orbit may result in an estimate of the orbit which is not that precise. Additional observations can gradually increase the precision of orbital calculations as discussed here, where the Minor Planet Center (MPC) has automation to make tens of thousands of improvements to orbital calculations every day:

Minor Planet Center

The MPC first identifies new observations with known objects or determines that the object is new. All orbits of identified objects are updated and improved daily...

Recent upgrades to computer equipment allow the MPC to calculate tens of thousands of orbit improvements per day.

So the precision of the orbital calculations of those objects is increasing as additional observations are made.

Maybe a rough analogy could be if you see a plane flying overhead with your eyes, and you know where north is and you estimate it's going somewhere between North and East. So you have some idea where it's going (Northeast) even if your visual estimate is not that precise. Then you could get some instruments like a theolodite and plot the plane's path more precisely. First, you might say its direction is between 42 degrees and 52 degrees if you've only observed it a short time. After a longer observation you might increase the precision of your estimate and say its heading is betweej 45 and 50 degrees. Eventually maybe you determine it's between 46 and 47 degrees. The more measurements you make the more you can increase the precision of your estimate.

But you already knew it wasn't going to crash into the ground to the West when you made your original 42 degrees to 52 degrees measurement, which is approximate but not very precise. Once you know it's heading is between 46 and 47 degrees, that's a lot more precise, but that doesn't affect your knowledge that it's not going to crash off to your west.

Even when you know the heading is between 46 and 47 degrees, can you still improve the precision? Maybe if your equipment is good enough, you might eventually narrow it down further, and say its heading is between 46.2 and 46.5 degrees, and maybe more observations can narrow that even further. So at what point does the trajectory become "precise"? That depends on how you define precise, and I repeat it's not a binary "we know it or we don't know it" as you are trying to suggest, each additional observation potentially allows us to increase the accuracy of the orbital calculation.

The boulders are challenging because they are difficult to observe due to their distance and small size, but they have been observed and measured, enough to be comparable to the analogy above where one could say the plane headed roughly northeast is not going to crash to the west. You might not know if its heading is 40 degrees or 45 degrees or 50 degrees (or actually 46.3 degrees), so you don't have a precise heading, but you don't need to know that to know it's not headed west, just as you don't need an extremely precise orbit to know an object like Dimorphos isn't coming near the Earth.

a reply to: Arbitrageur

You keep switching between the asteroids and the debris that was flung from them on the impact.
In regards to know trajectory, I'm talking about the debris.
They only have an idea of the velocity of the debris, no trajectory.
Therefor, according to the statement given, they cannot say it does not pose a risk, they can only assume.

As for the asteroids themselves, well they say PCD 2017 its an exercise but know from the past how exercises turn out.
Event 201 is as the most recent example i can offer but you have been here too long to say you haven't seen other examples.

originally posted by: datguy
a reply to: Arbitrageur

You keep switching between the asteroids and the debris that was flung from them on the impact.
In regards to know trajectory, I'm talking about the debris.

Asteroids are all different sizes. I gave you examples of how asteroid orbits are initially estimated and continually refined. The "debris" of the boulders is technically just smaller asteroids. Because the boulders are some of the smallest we've observed, the observations are more difficlt, but the concept is similar, initial measurements give an indication of the trajectory which additional measurements make more precise. The process of making additional measurements of either the large asteroids or the small boulders allows more precision in orbital calculations

a reply to: Wolf8740


wtf thats first for me. I did a quick google of "dart mission" to see what links I could find between the space force and this specific mission, and a satellite came flying onto the page, crashed and knocked the page sideways. now my google search page is crooked....



I did learn something new today though. I did not know that the DART mission was launched by Space X.
Now I am even more concerned than I was before as I am pretty sure Elon is the anti christ.

a reply to: datguy

The supposed volcanic eruption of a year ago in the south Pacific is now being considered to be a possible cause of the recent global warming. Having released all that water vapor into the upper atmosphere. BUT... I saw video of the explosion and there was clearly a moving object heading right at the sight of the explosion and many felt it was an impact, not an eruption. And right after that NASA got very squirrely touting about their ability to safeguard the planet with advanced warnings and asteroid tracking, Now i read tha the eruption produced very little sulfur which was unusual for a volcanic eruption. This points to an impact.
So why did they try to cover this up? We got hit by a piece of rock, a fairly big one. It got by them. NASA is not exactly known for being at the forefront of knowing what to do or whats going on anyway.

a reply to: Dutchowl

That's very interesting, I would love to see that video.

I remember reading that some studies were done on potential asteroid impacts and how the Tonga eruption shared some of the same characteristics of an impact.

Tonga volcano eruption yields insights into asteroid impacts on Earth

Do I? Do I? Get to sing the doom song?

Here is an additional update with new information that was presented last month, of observations that were taken about 1 month after the DART impact.
These findings further the idea that the "precision" of past observations are not so precise and unreliable.

New Post-DART Collision Period for the Didymos System: Evidence for Anomalous Orbital Decay
Full Submission PDF

Or, in laymans terms...

Something Weird Is Going on With the Asteroid NASA Smashed

But as Swift and his charges at the Thacher Observatory found when looking at Dimorphos' orbit more than a month after the initial collision, the asteroid's orbit seems to have continued to slow down — an unexplained turn of events, considering that most astronomers expected it to return to its original orbit speed pretty quickly.

"The number we got was slightly larger, a change of 34 minutes," Swift told New Scientist. "That was inconsistent at an uncomfortable level."

Seems something in the original calculations were off lending to the idea that there are more unknowns with these objects.
In regards to the Debris that was knocked off in the initial impact there is a theory that it may have been recaptured by the asteroid.

Asteroid behaving unexpectedly after Nasa's deliberate Dart

One explanation for the asteroid's orbit continuing to change so long after the Dart collision is that material thrown up by the impact, including rocks several metres across, eventually fell back onto the surface of the asteroid, changing its orbit even more.

I tend to not agree with that conclusion as the dates for the Hubble images, post date the findings of this new observation. So the findings of the increased and continued decay of the orbit of Dimorphos was prior to the Hubble findings of the scattered debris.
This lends to the idea that they still don't know the how the full impacts of the DART mission, pun intended.