EPOXI Mission News Options

[Paolo]

I was reading an article about H2 in an Italian popular astronomy magazine. it mentions as a possible origin for the nucleus' smooth surface tidal interactions with Jupiter during the April 1971 flyby at 0.09 AU.
Anyone heard of a similar theory? My impression is that the distance is too large for it to tear apart and re-aggregate even a loosely-bound "rubble pile", but maybe I am wrong.

[Gsnorgathon]

.09 AU would put it ~7 times farther out than Callisto. I dunno nuthin' 'bout no gravity, but that seems awfully far to do any sort of resurfacing.

[Phil Stooke]

Agreed. The idea isn't bad but I might be looking for an earlier and much closer encounter if orbit data are good enough - might be too chaotic, though.

Phil

[Paolo]

there is a new article on EPOXI's "Earth as an alien planet" observations on arXiv today
Colors of a Second Earth II: Effects of Clouds on Photometric Characterization of Earth-like Exoplane

[Juramike]

Very cool. Thanks for that link!

[Paolo]

I noticed this paper on Astronomy & Astrophysics Earth-based detection of the millimetric thermal emission from the nucleus of comet 8P/Tuttle (in free access at this moment)

It seems comet Tuttle has yet another dumbbell-shaped nucleus:

Harmon et al. (2008, 2010) interpreted their Arecibo radar observations of the nucleus of comet 8P/Tuttle as implying a contact binary and proposed a shape model composed of two spheroids in contact. Lamy et al. (in prep.) found that the light curve of the nucleus derived from their Hubble Space Telescope observations was indeed most accurately explained by a binary configuration and derived a model composed of two spheres in contact.

[Paolo]

I was expecting tomorrow's "Science" to include articles on early MESSENGER science and instead: EPOXI at Comet Hartley 2

[Phil Stooke]

A nice summary, but don't panic, folks, there's no new map of the nucleus yet! Interesting description of the rotation state though - a long axis mode like those of Halley, Toutatis and maybe Hyperion.

Phil

[ugordan]

Looks like the Rosetta Steins data wasn't the only one to hit the Small Bodies node recently. Here's Hartley 2 in natural color, OGB filters overlaid over a slightly better quality (closer and less smeared) clear frame. A bit of gapfill was used from that low res OGB data at the right limb where deconvolution ringing was caused by proximity to the image edge. Magnified 1.5x from the original pixel scale.



There's this and the outbound color shot, but it's badly smeared. The rest of the HRI frames appear to be clear frames only...

[Phil Stooke]

Very nice! Thanks.

Phil

[Decepticon]

ugordan - Amazing work!

[machi]

Comet Hartley 2 from High Resolution Imager. Color data are similar to the Ugordan's image of Hartley. Only difference is, that I used red filter and not orange one.
I was focusing more on nucleus, so I used higher resolution underlaying image and jets are somewhat suppressed (and processed with different type of deconvolution).
Image has original size with resolution 4.5 m/pix (original resolution of color images is around 15 m/pix).

Attached thumbnail(s)

 

[ugordan]

Nice! I used "orange" because being centered at 650 nm it is in actuality red, whilst the "red" filter is centered around 750 nm so is in fact near-infrared.

[machi]

Thanks!

So this is result, when one looks more on filter names and not on nanometers.

[ugordan]

Even though that name is a bit clumsy, I actually quite like the way they chose HRI imager filters, a simple and straightforward approach. Pretty much each filter has a bandpass of 100 nm, sharp cutoff and neighbors nicely with the next filter and the wavelengths are easy to remember. If it wasn't for the defocus problem, it would have been one sweet instrument.