Why is the Times reporting only now about Hayabusa-2 ?
Hayabasa has not only collected samples but also analyzed them and found that Ryugu is entirely made of material from other asteroids.
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"Why is the Times reporting only now about Hayabusa-2 ?"
The article has a link to one of the Times's earlier reports on Hayabusa2. Scroll down to the photo that has the name "Hayabusa2" in its caption.
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If you look closely you’ll find a Starbucks.
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How does an asteroid come to be made up of rocks or boulders, unless the rocks are remnants of something much bigger?
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"... unless the rocks are remnants of something much bigger?"
Scientists think some of the larger rocks are fragments of an older body. From the abstract of one of the papers:
"Our findings imply that ages of Bennu’s surface particles span from the disruption of the asteroid’s parent body (boulders) to recent in situ production (micrometre-scale particles)." (DellaGiustina, et al)
(Follow the link in the article to get to the abstracts.)
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@Michael Cooke
Here's more detailed and better information about Hayabusa's findings at the Ryugu asteroid:
https://www.bbc.com/news/science-environment-47633649
it's kind of astonishing that a bunch of rocks only 1600 feet in diameter can generate enough gravity to hold itself together, especially given the centrifugal force generated by its rotation. How does that happen? Or is the stuff cemented on some way, by heat, or Gorilla Glue?
I wonder if the scientists, in shooting bullets into such a small body, consider the possibility of altering the asteroid's orbit. According to Wikipedia, Bennu has a 1-in-2,700 chance of hitting Earth between 2175 and 2199. Is that chance now increased? You know - butterfly flapping its wings in China...The universe is an infinite mystery, with its very origin, not to mention how it operates, forever hidden from us. We have to tread lightly.
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"... the possibility of altering the asteroid's orbit."
Putting a spacecraft into orbit around an asteroid changes the asteroid's orbit slightly. And in a sample-return mission, there is another slight alteration in the asteroid's orbit when the spacecraft leaves the asteroid's orbit.
Further, when an active asteroid ejects matter, its orbit is slightly altered.
IOW, there are too many uncertainties to say whether firing a projectile into an asteroid would cause the asteroid to collide with the Earth.
For a broader view of this subject, do web searches for "orbital mechanics", "n-body problem", and "stability of the solar system".
For technical introductions, see:
* "Fundamentals of Astrodynamics" by Bate, Mueller, and White.
* "Introduction to Space Dynamics" by William Tyrrell Thomson.
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@William LeGro - just as likely decreased
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@GMF and then spend a few years understanding the math, and a few more on your PhD thesis, Envelope of Uncertainty in the Projection of an Intentionally Perturbed Orbit.
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eerily sublime
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These images are incredible!
I admire the scientists on this project and appreciate the opportunity to see these gorgeous results, which sit atop a heap of much less glamorous toil.
The phases of matter fill me with wonder.
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Amazing. The surface reminds me of the bottom of small streams in Maine where different sizes of gravel fit tightly together or even caddisfly cases! To think that one of these things might someday crash into earth and destroy the earth as we know it. How is it possible that some of us are wondering how carbon will be found in these rocks while others are denying that we are descended from millions of years of hominid evolution.
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