Mission: Hayabusa 2 Options

[Paolo]

Perhaps it could have a life beyond its prime mission like Stardust did.

that is also my impression. it could not have been done with Hayabusa because by the time it returned to Earth it was so badly crippled that it was essentially unusable

[pandaneko]

There was a short TV programme this evening here on NHK. In it I noticed
two things. I am not sure if the first was new to me, but the second
was.

1. Mid-air explosion will be monitored by a small floating camera
while the main body hides away.

2. The sampler horn now has acute angled teeth all around
the inside edges of the opening which will touch the ground.
This is just in case the ball bearing fails to fire properly.

How do we know there are loose particles? If there is water then
the whole thing may be rock solid. That is my imagination. P

[Blue Sky]

If there is water then the whole thing may be rock solid. That is my imagination. P

Given what happened on comet 67P, that may very well be the case.

[centsworth_II]

Unless I'm wrong, the target of Hyabusa 2 is an asteroid and not a comet, and a very small asteroid at that, why this talk about ice? If the surface is rock hard, I would expect it it to be because it is rock, but loose material on the suface of asteroids and comets seems to be the rule rather than the exception so far.

[katodomo]

1999 JU3 is a carbonaceous C-Type asteroid being thought to contain hydrated minerals and organic material, or by its spectrum at least a certain amount of water.

Itokawa, contrasting that, was a rocky S-Tye asteroid. Each Hayabusa mission (1,2,Mk2) is explicitly aimed towards a different type of minor body.

[centsworth_II]

1999 JU3 is a carbonaceous C-Type asteroid being thought to contain hydrated minerals and organic material, or by its spectrum at least a certain amount of water....

I guess one of the things Hayabusa will discover is if there is any water present apart from hydrated minerals, although I don't know how Hyabusa will look for volitile, free water in a sample.

Hyabusa 1's active collection system, "the bullet" failed, but there was some material collected passively. I looks like teeth have been added to enhance any passive collection, but hopefully the active system will work on Hyabusa 2. As I see it, the teeth can only help, not hurt in any eventuality.

[pandaneko]

Launch has been postponed to a date late than 1 December,
due to expected bad weather. If successfully launched it would
be flying out like in the movie here.

https://www.youtube.com/watch?v=vq9vZhf79Zg

It is actually H2B-4, carrying cargo to ISS as seen from Okinawa,
but H2A-26 must be looking like that, I think. The movie is meant
to be an early Christmas illumination. The rocket appears to be
lonely, somehow... P

[pandaneko]

The more I think about comets and asteroids the more confused I get.
What is the difference between them? The former are eccentric, dirty
snow man and the latter are rocky non-eccentric, OK, but is that all?

Can there not be tiny astronomical obecjts in the asteroid belt entirely
(100%) made up of ice? Equally, can there not be those entirely rocky
(100% rock) objects that have very eccentric orbits?

In fact, I seem to remember reading somewhere that there are
eccentric astroids that are dangerous, because detection is difficult.

All I seem to be saying is that there may be hybrids somewhere out there. P

[nprev]

There are intermediate/transitional objects, Pandaneko. One example is 'asteroid' 3200 Phaethon.

[pandaneko]

There are intermediate/transitional objects, Pandaneko. One example is 'asteroid' 3200 Phaethon.

Thank you. Very interesting and informative, indeed. This pushes me
into thinking like;

Iron meteorites must mean that somewhere out there there are all metal
asteroids. Likewise, there must exist all ice asteroids somewhere. Flagments may fall
into the atmosphere, but they melt and leave nothing to suggest there are
all ice astroids.

In fact, there may be anything at all out there, all kinds of
unimaginable hybrid asteroids, I think. P

[nprev]

Yep. Things in nature generally exist along a continuum. Re metal asteroids, check out 16 Psyche.

[pandaneko]

New launch schedule has just been announced. It is now set for
13:22:43 JST. P

[Paolo]

and don't forget Main Belt Comets, or damocloids. not to mention the probable presence of water ice on the surface of Ceres, or the discovery of refractory materials in the samples from comet Wild 2.
it is becoming more and more clear that the difference between comets and asteroids is not as clear cut as it seemed up to 20 years ago, and that there is actually a sort of continuum between the two

[pandaneko]

New launch schedule has just been announced. It is now set for
13:22:43 JST. P

Silly me. The date is 1 December. P

[pandaneko]

and don't forget Main Belt Comets, or damocloids. not to mention the probable presence of water ice on the surface of Ceres, or the discovery of refractory materials in the samples from comet Wild 2.
it is becoming more and more clear that the difference between comets and asteroids is not as clear cut as it seemed up to 20 years ago, and that there is actually a sort of continuum between the two

Thanks, Paolo

for making me aware of icy asteroids and metal asteroids.

To me, metals are easier to understand as they are elements.
Since our Sun is the only fusing body yet to explode our solar
system's metal asteroids (raw materials, at least) must have come
from inter galactic space (presumably as gaseous metals).

However, water is not an element and that makes me feel uneasy.
Can water be produced locally inside our solar system? Or, did water
also come from outside? Do we know at all? P