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Mission: Hayabusa 2
nprev
post Yesterday, 11:37 AM
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Remember that appearance does not equate to composition. Relatively fine-grained material of all types on any body will look quite similar, but it originated via a variety of processes. For example, the 'sand dunes' of Titan would quickly melt or sublimate under terrestrial conditions. wink.gif


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A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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pandaneko
post Yesterday, 12:44 PM
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Does the Sun spin?

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pandaneko
post Yesterday, 12:48 PM
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I am trying to build up of an image of our solar system formation in my own small way.

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nogal
post Yesterday, 01:14 PM
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QUOTE (pandaneko @ Sep 25 2018, 01:44 PM) *
Does the Sun spin?

It does, and does rotate faster near the equator than at the poles. Speed can be estimated from sun spot motion. See, for instance this wikipedia article on "Solar rotation"
Thank you for all your contributions to this forum.
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neo56
post Yesterday, 08:58 PM
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Just for fun... what if Ryugu was on Paris tongue.gif

Attached Image


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Floyd
post Yesterday, 10:46 PM
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This really helps get scale. The little rock on the surface are not very little.


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mcmcmc
post Today, 07:29 AM
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Useful for upcoming MASCOT delivery: you can know in realtime Hayabusa 2 altitude by reading this file:
http://haya2now.jp/data/data.json

I reverese-engineered the source, and after several calculations it appears that H2 altitude in km is given by this formula:

A = 354 / sqrt(ONC_A)

File is updated in realtime during operations, and ONC_A value is used to set the size of the disk which represents Ryugu in Hayabusa2 simulator.

ONC_A represents the area of the disk.

You can then use this page to figure out how big the rovers would appear:
http://win98.altervista.org/telescopio.html

(MINERVA-II rovers have a 0.00018 km diameter and 0.00007 km height.)
(MASCOT is around 40x30x20cm, hence maximum dimension is 0.00040 km)

I'm trying to setup a page which automatically determines pixel size of the rovers depending on altitude, but I am encountering difficulties with cross-site data access.


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pandaneko
post Today, 09:27 AM
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Here is my simplistic view of the formation of our solar system.

Big bang, then elementary particles collied with one another, producing light atoms. Light atoms in turn collied amongst themselves and
accretion started all over the univere.

Here, I turn my attetion to our own. Sun was being formed, but smaller accretions were also taking place all over in our solar system.

There must have been porous asteroids, already hardened, rock solid asteroids, and those somewhere between. They kept colliding over
astronomical time scale.

If, as I have been reminded, there had been post collisional accretions then most of healthy (not bombarded by other asteroids) and
unhealthy (affected but still kept accretion) asteroids must be like Ryugu, with an equatorial vulge.

I bet Bennu will be looking like Ryugu and perhaps, Ikokawa was one of the odd asteroids?

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