Asteroid struck by Nasa probe leaves 10,000km trail
A new image shows that an asteroid which was deliberately struck by Nasa’s Dart mission has left a trail of debris stretching thousands of kilometres.
A telescope in Chile captured the remarkable picture of a comet-like plume spreading behind the giant rock.
The probe was crashed last week to test whether asteroids that might threaten Earth can be nudged out of the way.
Scientists are working to establish whether the test was a success, and the asteroid’s trajectory altered.
The extraordinary image was taken two days after the collision by astronomers in Chile, who were able to capture the vast trail using the Southern Astrophysical Research Telescope (Soar).
It stretches for more than 10,000km (6,200 miles), and is expected to get even longer until it disperses completely, and looks like other space dust floating around.
“It is amazing how clearly we were able to capture the structure and extent of the aftermath in the days following the impact,” said Teddy Kareta, an astronomer involved in the observation.
The trail of debris would be monitored over the coming weeks and months, Michael Knight of the US Naval Research Laboratory said.
The $325m (£240m) Dart mission saw the probe deliberately smashed into the asteroid, destroying the spacecraft in the process. It will be some weeks before scientists know for sure whether their experiment has worked.
However, Dr Lori Glaze, the director of planetary science at Nasa, was convinced something remarkable had been achieved by the mission.
“We’re embarking on a new era of humankind, an era in which we potentially have the capability to protect ourselves from something like a dangerous hazardous asteroid impact. What an amazing thing; we’ve never had that capability before,” she told reporters.
Scientists will determine whether the mission has been successful by studying the changes to the orbit of Dimorphos around another asteroid called Didymos.
Telescopes on Earth will make precise measurements of the two-rock, or binary, system.
Dart is an acronym for Double Asteroid Redirection Test.
It was designed to do “exactly what is says on the tin”, mission lead Dr Andy Rivkin told BBC News.
The technique could be used if there was an asteroid heading for Earth at some point in the future, he said, describing it as a “very simple idea” – ramming the spacecraft into the object you are worried about, and using the mass and speed of the craft “to slightly change the orbit of that object enough so that it would miss the Earth”.
See more here bbc.co.uk
Header image, montage of Hubble and Webb telescope images: The Sky At Night magazine
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aaron
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cool, more cgi images
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Howdy
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“It stretches for more than 10,000km (6,200 miles), and is expected to get even longer until it disperses completely, and looks like other space dust floating around.”
Right. space dust? Are you having a laugh?
Don’t pollute the planet, do space instead where eventually the evidence will disperse. Why not just dump all of Earth’s rubbish in space and have done with it… Out of sight, out of mind. There’s plenty of room and it will laughingly, eventually be disguised as dust Grow up for Heaven’s sake!!. Don’t tell me about cost either.
“Scientists are working to establish whether the test was a success, and the asteroid’s trajectory altered.”
Why hit it at such an oblique angle? Scared it might have real repercussions? If a space object approaches on a direct line with the planet, NASA will need a lot more inertia than a Noddy car craft as used there to cause an effect.
Looks a total waste of time and resources for more playtime stories.
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lloyd
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So being able to deflect errant asteroids is a waste of time? Angry Much?
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Howdy
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You bark up the wrong tree Lloyd, it’s called being realistic actually.
“Angry Much?”
Second time I’ve seen that in a week. Is it a trend or something, because other than that, it’s meaningless.
They can’t deflect squat. They don’t even know if they deflected it. They need to know the holding force of orbit at least before they can do that. If they really knew what the were doing, they wouldn’t need to experiment in this ‘no-clue’ fashion and wait to see what happens, would they? It’s called the ‘suck it and see’ approach. AKA, hit and miss, not aware of what will really take place. How expert can they be.
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Herb Rose
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Hi Howdy,
A benefit of this experiment is that they will be able to find the mass of the orbiting asteroid, its velocity, and its distance from the large asteroid. Using Newton’s formula (as they did to determine the mass of the planets) they will be able to calculate the mass of the orbited asteroid and get such an unreasonably large number that they will have to admit that Newton (and Einstein) were wrong and gravity has nothing to do with mass.
Herb
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Howdy
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Didn’t they need to know the velocity etc allready to target the space craft precisely in the first instance? How do they deduce the mass from a crash that in all probability achieves nothing?
They Have to overcome the force that holds the asteroid in place before they can do anything else.
On PSI, I read that once
Can’t comment on Newton and Einstein, Herb.
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Herb Rose
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Hi Howdy,
They know the mass and velocity of the satellite so by using the conservation of momentum (inertial mass equals gravitational mass) by noting the change in the orbit they can determine the mass of the asteroid instead of guessing at it.
There has to be a change since energy doesn’t disappear.
Herb
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Howdy
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What if the asteroid speeds up momentarily? The image shows a square on rear collision.
Not only do they have to overcome the asteroid mass by a sufficient amount to even cause a readable deflection, how do they know the strength of the force that maintains the orbit? And even if they changed the orbit, doesn’t the balancing force that kept it there in the first place put it back? If you upset a balance that existed, something else has to change to recover that equilibrium.
If a vehicle is going round a long curve and you ram it with a babies push chair from behind, the net effect on the vehicle will be so small as to be of no consequence. Isn’t it the same thing here?
Herb Rose
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Hi Howdy,
The distance an orbiting object is from the object it orbits is determined by its velocity (Keppler’s law dV^2 = C) so all satellites at the same distance will travel at the same velocity regardless of their masses.
The new distance the asteroid is will tell how much the energy of the asteroid with the addition of the energy (1/2mV^2) changed from the satellite which in turn will tell us C (mass?) of the asteroid being orbited. If the satellite asteroid loses velocity (head on collision) it will move closer to the core asteroid and gain velocity. If the orbiting satellite gains energy (rear end collision) the distance will increase and it will lose energy and end up in a higher orbit with less velocity.
Herb
Howdy
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Thanks Herb, but that doesn’t answer the many questions I have.
I have a tendency to disbelieve a lot of man-made laws and other such since they are so often changed, or corrected as new factors are discovered etc. Indeed, some of the ‘old masters’ are now challenged by more than a few. You yourself have doubts.
I’m leaving it here. Thank you for your usual patience in trying to make me understand. Take care Herb
pk47
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What you say is correct if it was a purely elastic collision. This is highly inelastic, evidenced by the large debris trail. Sorting all this out to back calculate the asteroid’s mass would be challenging, to say the least. I’d say you have to bracket the calculations by assuming a range of elastic momentum transfer accomplished.
Herb Roser
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Hi Pk47,
I would consider an inelastic collision where the masses add. It doesn’t really matter since you would be calculating the mass of the asteroid being orbited.
Herb
pk47
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Depends on how much kinetic energy was lost in causing permanent deformations etc. in the parts of the system. The satellite clearly had permanent deformation from the impact; depending on exactly what happened at the asteroid’s surface, a significant amount of energy may have been lost there in fracturing the rock.
Herb Rose
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Hi Pk47,
The energy (V^2) of the orbiting asteroid can be determined by its new velocity. That velocity, the distance to the other asteroid, and the gravity constant (G) are all that is needed to determine the mass of the other asteroid and determine its density..
Herb
Howdy
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“On PSI, I read that once”
Forget that part.
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