Perhaps...
it would be better to chuck Bruce. After all we have a planet to save.
NASA has okayed one of its save-the-world-from-asteroids proposals to move to the preliminary design phase, on the way to a hoped-for launch early in the 2020s. If it goes ahead, the DART – Double Asteroid Redirection Test – will start with what the space agency describes as “a non-threatening small asteroid”. That way, …
7. The fridge, being an intelligent IoT device, will notice that it needs to stock up on fresh milk, but since there is no Wifi connection in the asteroid belt it will fail to connect to Walmart and subsequently the control system crashes with an unexpected error. The thrusters therefore fail to fire, and the fridge crashes back to Earth.
Damn right it does - DART brings to the binary additional momentum and angular momentum so the system total changes and consequently its orbit around the sun changes! Maybe not by a lot but it is still a change. So either Tom Statler was misquoted or the word "significantly" was dropped.
I don't believe that a scientist can make such a high school physics mistake
Conservation of energy & momentum. Right. It will change the orbit of the pair. What the scientist probably tried to explain was that this test won't “change the orbit of the pair around the sun” by a measurable amount.
This statement is probably just meant to reassure all that this test will not drop a stone on anyone's head.
Ok.. so this "test" changes it's orbit and not for the good.... The next time it comes around, NASA will have the real thing fired at it. Hopefully with the orbital mechanics sorted out...
I do wonder why no one asked Mr. Statler the obvious question in response to his answer: "Would you stake your life on that statement?".
Yes.
To estimate the effect: Imagine firing a shell against a 2km high mountain for comparison.
This kind of test will change the combined orbit o the binary maybe by a few dozen meters. Given the average distance to earth is a few 100 million km and the way orbital mechanics work, the chance of impact is changed from zero to zero.
"I do wonder why no one asked Mr. Statler the obvious question in response to his answer: "Would you stake your life on that statement?"."
The obvious answer is to paraphrase Homer Simpsons on this:
"I am 100% absolutely certain that this is what will happen. If I'm wrong may we all be horribly crushed from above somehow."
(According to Wiki - Simpsons Season 6, Episode 14, "Bart's comet - ~1995)
If you're going to be really pedantic, then just walking across the room will alter the shape of the Earth's gravitational field, which will alter the motion of everything in the solar system.
Not by a measurable amount though, and certainly less than the change in the course of the asteroid(s) caused by the high powered radar they're presumably going to shine at it to pin down it's position (which in itself probably won't make a measurable difference).
Die regte term is "in sy moer in"
But yes, they'll have to arrange for Zupta and Co to be present at Nkandla when the rock comes crashing down.
And to satisfy PETA, the chicken coop (and cattle kraal) be relocated to a safe location prior to impact.
Fire pool can remain, it'll just add a lot of steam to the inferno.
around 6 km per second (“about nine times faster than a bullet”
Many of us in the old world are not really familiar with how fast a bullet travels - is it time for a new Reg Standards Bureau unit? The 'velocity of a sheep in vacuum' is a bit limited.
A tractor on a country road on August Bank Holiday?
The "dead cert" I had a tenner on in the Grand National?
And we could probably derive a unit of acceleration due to gravity based on observation of the speed of a £DUP as it falls off a magic money tree to the ground.
"A tractor on a country road on August Bank Holiday?"
Speed of a caravan on the A82?*
**
*In case you're not Scottish, this is the main road from Glasgow to the West Highlands. Almost single-track in places.
**Not just on August Bank Holiday, because a caravan on the A82 takes all summer to get from Dumbarton to Crianlarich.
"Many of us in the old world are not really familiar with how fast a bullet travels"
just rough ballpark - the bullet from a .223/5.56 NATO round is zipping along at around 6531 Linguine/sec. The 7.62 projectile from an AK-47 is somewhat slower at around 5107 Linguine/sec. There's a speedier round called the .204 Ruger that zips along at 9144 Linguine/sec with a lightweight bullet. By comparison, the .45 ACP pistol bullet is barely flying at 1850 Linguine/sec.
So, eh, there's a lot of potential variance in his comparison of "nine times faster than a bullet".
From "The Book"
There was one inhabited planet in the seventh dimension that got used as a ball in a game of intergalactic bar billiards. It got potted straight into a black hole, killing ten billion people.
It only scored thirty points.
I wonder if they can arrange a canon off it's larger twin?
There's a very silly (and enjoyable) free-download game called Pluto's Revenge, which involves exactly that. Pluto has a baseball bat and whacks asteroids at the other planets. Because it's miffed at being downgraded from true planet status.
Also has a deeply weird soundtrack.
"Well, it _was_ non-threatening..."
...until some numbskull NASA bloke decided to recycle his old fridge and send it on a one-way trip to some rock...
At least we have until "the early 2020's" to enjoy ourselves and not have to worry about too much...like Trump, Brexit, Syria, Russia, China, IS, the Tories, Corbyn, Putin, North Korea, Microsoft, Musk, TOWIE, Bake Off, Strictly, Murdoch, England teams.....so, not many will remember the odd case of a 160m wide mini-asteroid being sent off course and no doubt delivering a huge surplus of raw materials to the soon to be depleted Earth.
I wonder if NASA could sell the asteroids mineral wealth to the highest bidder and hence ensure an expedited delivery direct to the end customer !!
Only a small change in a threatening asteroid's orbit would be needed to swing it away from Earth, as long as it happens “well before the predicted impact”.
I missed the part where this "well before the predicted impact" warnings comes and we actually have the technological capacity to do anything at all about said impact withjin a 20y timeframe.
I'm really starting to hate nerds who watch Sci-Fi and then go to NASA.
Well, modify the security- and cost-obsessed current space project setups to be result-oriented.
Then give it 5 years and just 10% of NATO's combined budget and we'll probably be fine...
But I agree : Observing it earlier would take a lot of stress out of that project...
Only a small change in a threatening asteroid's orbit would be needed to swing it away from Earth, as long as it happens “well before the predicted impact”.
A collision occurs when the asteroid and the Earth are at the same place at the same time. Since the Earth's diameter is only 13,000 km, and the asteroid would be impacted at say 500 million away, it only needs to be slowed down by less than a millionth of its orbital speed to avoid its orbit passing through the Earth's orbit at the instant that the Earth was also at that point. Passing through the Earth's orbit six hours later than the Earth passes through the same point would more than sufficient. This is more "imperceptibly slowing it down" than "swinging it away".
Turn of the century I was living in N Cal, up in the Gold Country we had a darts league, I was a member of the local team. There were a few ex-pats like me playing but mostly yanks, there were quite a few of them who could throw a pretty mean dart and aerospace bods are a dime a dozen in N Cal.
If we know the mass of the fridge, impact velocity and the mass and velocity of the asteroid - shouldn't we know what's going to happen?
Realistically, if we have a big lump of rock coming at us, does anyone think that 3 years is enough time to get ready for it? Nobody even spotted the Chelyabinsk meteor - had that been a nickel rock, somewhat larger, we'd still recovering (if we were lucky). Does anyone wonder if there are bigger lumps in the meteor streams that we pass through every year?
Let's see...
Maximum change in asteroid velocity would require a direct hit normal to the surface.
Deviations from a normal impact will 'waste' energy changing the angular momentum, but not affect the velocity of the body.
Assuming a direct impact normal to the surface (ie... in line with the centre of mass)...
Mass of NASA object ... I believe I read somewhere that it was one ton? one tonne?
Let's go with tonne...
Velocity of DART approximately 6,000 m/sec.
Stony asteroids range from about 3 - 5 gm/cm^3, or 3 - 5 tonnes/m^3.
Lets go with 3 tonnes / m^3.
Diameter of smaller asteroid is about 160 m. Estimate mass at 3 x (4/3) x 80^3 x pi, or roughly 6.5 million tonnes.
Maximum velocity change is thus on the order of 6,000 m/sec / 6.5 x 10^6 or about .00093 m/sec, or .9 mm/sec.
But... this is unlikely to be enough to break up the binary asteroid pair, so gravity will couple the two masses, the second of which is about 780 m in diameter, thus with a mass on the rough order of (780/160)^3 = 116 times greater, implying a probable maximum change in velocity of the asteroid pair of about .9 / 116 = .0078 mm/sec.... or less if the energy gets converted into spin, or potential energy in the binary pair?? (need to think about that some more... it's been a long time since I've had to do physics).
Someone with a better grasp of orbital mechanics will have to tell us how much that will change the orbit of the asteroids...
Yes, I know there are various assumptions of geometry and material, etc, here, but this is order of magnitude stuff, not an exact solution.
This post has been deleted by its author
For the foreseeable future it's going to take a looooong time to get from A to B in our solar system, which means you'll get cooked by a lot of radiation.
Those elaborately crufted Aluminium cans that NASA, ESA, JAXA, ISRO are the Chinese build have roughly the radiation protection equivalence of 0.5% of the Earths atmosphere. OTOH 3m of Mars regolith will give you radiation protection equal to Earths atmosphere.
But that's a damm heavy lump of mass to get into LEO.
Asteroids are already in orbit. Even a small one one packs a huge amount of internal volume, and can still give you 3m thick walls.
This is the start of an actual viable way for humans to explore the Solar System.
I guess they're assuming that nothing is living inside the Asteroid. Just in case we haven't had enough Science Fiction today, or any day.
When I read the article, I thought that they would land their equipment (softly) on the larger of the pair and then use that as the base to launch the fridge at the smaller. Thus the momentum of the pair would be maintained. That's not what the video showed. And depending on how the larger is rotating, it could introduce uncertainty into the question of whether they'll hit the smaller at all. English probably needs a new expression for poor aim, because: "What's a barn, Daddy?"