Printable Version of Topic

Posted by: MarcF Oct 11 2017, 05:59 PM

Haumea was already weird with its size, shape, color and moons. Now it has also a ring :-)

http://www.nature.com/nature/journal/v550/n7675/full/nature24051.html?foxtrotcallback=true

"Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea’s equator and the orbit of its satellite Hi’iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea’s spin period..."

Best regards
Marc

Posted by: Patteroast Oct 11 2017, 09:11 PM

I'm super surprised. I would have thought the weird torquing non-co-planar orbits of Hi'iaka and Namaka would have made a ring system harder to maintain, not to mention what kind of tidal effects would happen with a non-spherical world! But I admittedly know basically nothing about orbital mechanics.

Another point in favor of Haumea being the TNO I most want to get a spacecraft to in my lifetime.

Posted by: Explorer1 Oct 12 2017, 03:42 AM

Apparently the new albedo measurements show it to be darker than previously thought (and thus larger). Even a 'New Horizons 2' style flyby could take advantage of the fast rotation, map more of the surface at high-resolution. We need a mission out there; badly!

Posted by: vikingmars Oct 12 2017, 07:51 AM

A world with an oval shape and rings...
Remember the novel "Mission of Gravity" by Hal Clement ?
A Sci-fi novel worth to be read.

Posted by: TheAnt Oct 12 2017, 05:52 PM

The fast rotating Haumea have been found to have a ring, even before finishing reading the text I had a notion there might be a connection with the fast rotation.
Amd the press release do indeed mention possible "....dispersal of surface material due to the planet's high rotational speed". (Yes the text say 'planet' not me.)
Anyway the findings presented on a page by the http://www.iaa.es/en/news/haumea-most-peculiar-pluto-companions-has-ring-around-it.

Posted by: nprev Oct 13 2017, 04:07 AM

ADMIN NOTE: Two topics were started almost simultaneously for this story; they've been merged into the first one posted.

Posted by: TheAnt Oct 13 2017, 03:24 PM

I agree, though one interesting possibility, cryovolcanism was based on the idea that Haumea was unusually bright.
Now that it's darker, perhaps its not the case. Yet Haumea remain among the more interesting of several KBO worlds.

Thales Alenia Space have made a study, not just for a flyby but orbiter!
It have several different mission profiles and proposed engines as it seem to be a bit of a speculation in future technologies.
The achilles heel is the power production, where they propose beta-voltaic batteries/panels which are long lived.
But even with predicted improvements to the technology still will not provide enough power. (24W/Kg predicted improvement to the technology, while 50W/kg needed for a 20 year mission profile.)

And the text do indeed have the title https://www.researchgate.net/publication/245140124_A_preliminary_assessment_of_an_orbiter_in_the_Haumean_system_How_quickly_can_a_planetary_orbiter_reach_such_a_distant_target

@vikingmars: I have indeed read "Mission of Gravity", and Haumea will also have variable gravity.
So you are proposing that the spacecraft need to have a lander that fails after it have landed and taken measurements?

Posted by: Explorer1 Oct 13 2017, 08:15 PM

I recall that in Clement's novel, the probe's scientific data is fully recovered by the natives; can't rely on that with Haumea!
Any idea how much surface gravity varies from the equator to the poles?