Eggs in orbit (APOD 23 Sep 2008)

[emc]

http://apod.nasa.gov/apod/ap080923.html

"Two moons walk single file into a bar... you'd think the second one would have noticed."

[bystander]

but can you balance them on end during an equinox?

[neufer]

http://apod.nasa.gov/apod/ap080923.html
-----------------------------------------------------------
http://en.wikipedia.org/wiki/Haumea_(dwarf_planet)

<<Haumea is a dwarf planet in the Kuiper belt, roughly one-third the mass of Pluto. It was classified as a dwarf planet by the International Astronomical Union and named after the Hawaiian goddess of childbirth and fertility. Although it is not spherical, Haumea is considered a dwarf planet because it is in hydrostatic equilibrium: its ellipsoidal shape is due to its rapid rotation (in much the same way as a water balloon stretches out when tossed) and not due to insufficient self-gravity. Prior to being given the name Haumea, it had been assigned the temporary designation of (136108) 2003 EL61. In their own work, Mike Brown's team at Caltech had used the nickname "Santa" as they first observed the object on December 28, 2004, just after Christmas. Because Haumea rotates roughly once every four hours, faster than any other known body in the solar system larger than 100 km in diameter, it should be distorted into a triaxial ellipsoid. The short rotation period of Haumea is likely to have been caused by a giant impact, which also created its satellites.

Dimensions ~1960 × 1518 × 996 km
Mean density 2.6–3.3 g/cm³
Sidereal rotation : (3h 55m)>>
------------------------------------------------------------

Lets try to counterbalance the centrifugal force by the equitorial gravitational force.

ω² R = g ................................ (Eq. 1)

with g the acceleration of gravity. With ω = 2 π/T this leads with (1) to:

T ≅ 2 √ (R)

if we approximate π² by g. T is de axial rotation period of the earth. With R = 6.5E6 m, T ≅ 5100 s: 1h 25m.

A spherical earth rotating this fast (period ~ 1h 25m) would tear itself apart by centrifugal force. Long before the catastrophic rotational rate of self destruction (period ~ 3h 50m), however, the earth would elongate into a prolate spheroid [like the large Kuiper belt object "Santa" (period ~ 3h 55m)].

http://en.wikipedia.org/wiki/(136108)_2003_EL61
-----------------------------------------------------------
Phase locked satellites elongate and tear apart at even slower rotation rates (period ~ 5h 25m) because differential gravity gradients are equally important (to centrifugal forces).

Neptune's Naiad (period = 7 h 4 min)
http://en.wikipedia.org/wiki/Naiad_%28moon%29

Mars Phobos (period = 7 h 39 min)
http://en.wikipedia.org/wiki/Phobos_%28moon%29
-----------------------------------------------------------
Only very small rigid solid asteroids or moons can rotate faster:
1998 KY26 (period = 10.7 minutes)
............................................................
http://spacewatch.lpl.arizona.edu/1998ky26.html

<<The asteroid 1998 KY26 was discovered by Tom Gehrels on the night of May 28, 1998 (UT) during a routine scanning session. Although appearing as a small dot on the screen like any other asteroid, this near-Earth asteroid has some interesting properties. First, it passed close enough to the Earth for radar observations to be taken. From light curve measurements, its rotation period was calculated to be 10.7 minutes - the fastest rotating asteroid known. In fact, it is the fastest known rotating body in the solar system! >>

[bstout]

What's the official name for the secondary APOD picture, the more detailed one you go to when you click on the primary picture?

Anyway, there's a mistake on this one, and I don't mean that it's different from the primary picture. (The primary picture shows Haumea and its moons, the secondary one shows the largest know Kuiper belt objects.)

The mistake is that the picture shown is obsolete: it has the temporary designations for the objects -- 2003 UB313, 2005 FY9, and 2003 EL61 -- rather than their official names -- Eris, Makemake, and Haumea.

I think they meant to have this picture:
http://en.wikipedia.org/wiki/Image:EightTNOs.png .

[orin stepanek]

When I was in school we had the Sun; planets; comets and the asteroid belt. Now we have dwarf planets, an oort cloud and the kuioer belt. Oh yes; eggs in space.
I wonder what other mysteries the solar system will have uncovered in years to come. We were always anticipating that tenth planet to be discovered; and now we are down to eight. If something is discovered in the outer regions that is as large as one of the inner planets; will it be designated as a dwarf planet because it's orbit is in a different plane then that of the eight? That probably won't happen; but you never know. They are finding planets in the systems of stars.

Orin

[jesusfreak16]

in reply to bstout:

http://antwrp.gsfc.nasa.gov/apod/ap080923.html

http://antwrp.gsfc.nasa.gov/apod/image/ ... sa_big.jpg

[bystander]

in reply to bstout:

http://en.wikipedia.org/wiki/Trans-Nept ... an_objects

[saberard]

"Haumea's smooth but oblong shape make it extremely unusual. Along one direction, Haumea is significantly longer than Pluto, while in another direction Haumea has an extent very similar to Pluto, while in the third direction is much smaller." Am I the only one who would like the writers of these otherwise interesting blurbs to proofread their work? Sloppy language bespeaks sloppy thinking. If anyone who reads this has influence over the writer(s), could he or she please try to remedy this probelm? Thanks!

[jesusfreak16]

Probelm?
Did you proofread your post before you submitted it?Everyone makes mistakes.
8)

[saberard]

These are not random postings. They are comments written for public consumption. By the way, the problem was that the sentences made no grammatical sense, not that there were any misspellings.
Sincerely.

[apodman]

Haumea's smooth but oblong shape make it extremely unusual. Along one direction, Haumea is significantly longer than Pluto, while in another direction Haumea has an extent very similar to Pluto, while in the third direction is much smaller.

This reads at grade level 12 and asks you to read 38 words. The first sentence mismatches a singluar noun with a plural verb. The second sentence links three clauses clumsily and omits a word. I've seen worse.

Haumea is about as wide as Pluto but longer and less thick. Being both oblong and smooth makes Haumea extremely unusual.

This reads at grade level 6 and only asks you to read 21 words that say as much as 38. It's easy to read, but I had no trouble reading the APOD description as originally written, either. The original is just not all that horrible; considering the low standards all over the internet and television, why pick on APOD? Nobody gives an Edwin Newman award in this forum, most astronomers don't keep Fowler on their bookshelves, and even Fowler ain't what it used to be.

proofread their work ... Sloppy language ... sloppy thinking ... remedy this probelm

the problem was that the sentences made no grammatical sense, not that there were any misspellings.

Maybe no misspellings by RJN, at least. You know, there's an "edit" button in this forum (if you're logged in) where you can correct your error. I generally scramble like mad to find and correct the errors in my posts before someone posts a reply and I get discovered as the imperfect first-pass proofreader I am. I live in a grass house and should therefore not stow thrones.

Note to jesusfreak16: I find it both cool and disturbing that you save a byte by leaving out the space between sentences. I never have to look and see who wrote it. Back in antiquity, my typing teacher told us "two spaces" after each sentence. When proportional spacing reached the common man, the rule changed to "one space". Your style makes me chuckle at the trauma I suffered during the transition. Circa 1993, Ventura Publisher inserted a space-and-a-half, and nobody uses Ventura any more - so much for compromise.

[emc]

I couldn't find any reference to an artist except NASA. And my search in the NASA site lead to a dead end. I'm betting there was a lot of collaboration to create it.

It's a cool rendering deserving credit.

[apodman]

Sloppy language bespeaks sloppy thinking.

Okay, sloppy language goes with sloppy thinking just as precise language goes with orderly thinking. But you can't hang a "disorderly thinking" tag on everyone whose writing comes up a little bit short, because it's still a few steps from orderly thinking to precise language.

If anyone who reads this has influence over the writer(s), could he or she please try to remedy ...

Writing needs to practiced with good advice and examples at hand and specific goals in mind - you can't simply "remedy" the bad and expect the good to appear.

Additionally, writing the APOD description requires the development of these specialized writing skills as a minimum:

1. Writing for a wide audience
2. Writing technical material
3. Writing clearly and simply
4. Writing hypertext with many in-line links
5. Keeping it short
6. Writing with style

Depending on what you have to write about, doing all six of these at the same time can sometimes be a challenge for a professional writer. If you're an astronomer first, a teacher second, a network administrator third, a technical ambassador to the world fourth, and a writer about eighth, you don't have time to wrestle the tough ones all the way to the ground regardless of how well developed your skills have become.

[makc]

I couldn't find any reference to an artist except NASA. And my search in the NASA site lead to a dead end. I'm betting there was a lot of collaboration to create it.

It's a cool rendering deserving credit.

you linked to wiki, but they DO have credits here:

Description: An artist's impression of (136108) Haumea and moons
Source: [1]
Date: April 2006
Author: A. Feild (Space Telescope Science Institute)

[neufer]

"Two moons walk single file into a bar... you'd think the second one would have noticed."

---------------------------------------
http://en.wikipedia.org/wiki/Hi%27iaka_(moon)

<<Hiʻiaka or Haumea I, nicknamed "Rudolph" by the Caltech team, was the first satellite discovered around Haumea. The team discovered Hiʻiaka on January 26, 2005. The outer of Haumea's two known satellites, it orbits once every 49 days. The discovery team missed by only a few years mutual occultations of Hiʻiaka and Haumea , which occurred in 1999 and will not occur again until 2138. Assuming Hiʻiaka has the same density and albedo as Haumea, its mass is 1% that of the mass of Haumea and its diameter is approximately 310 km.

Strong absorption features at 1.5 and 2 micrometres discovered in the infrared spectrum are consistent with absorption due to water ice. Their depth suggests that much of the satellite’s surface is covered with ice. Hiʻiaka's water ice absorption spectrum is stronger than that of any other body in the Solar System . This unique feature, and similar absorption lines observed on Haumea itself, led Brown et. al. to conclude that capture was an unlikely model for the system's formation, and that Haumea's moons must have been split off from Haumea itself.>>
---------------------------------------
http://en.wikipedia.org/wiki/Namaka_(moon)

<<Namaka or Haumea II, nicknamed "Blitzen" by the Caltech team, is the smaller inner satellite of Haumea. Its discovery was announced on November 7, 2005. It is inclined 39 ± 6° from the larger moon, but as of 2008 its orbit is not yet known. The measured brightness implies a diameter 12% that of Haumea, or some 170 km, assuming a similar surface composition. Namaka (probably) orbits Haumea in 34.7 days, and is inclined 39 ± 6° relative to the larger moon Hi'iaka. Namaka is large enough to perturb the outer moon Hiʻiaka and keep it from having a circular orbit>>
---------------------------------------

[emc]

I couldn't find any reference to an artist except NASA. And my search in the NASA site lead to a dead end. I'm betting there was a lot of collaboration to create it.

It's a cool rendering deserving credit.

you linked to wiki, but they DO have credits here:

Description: An artist's impression of (136108) Haumea and moons
Source: [1]
Date: April 2006
Author: A. Feild (Space Telescope Science Institute)

Thanks makc,

It's nice to have savvy people around. I was looking in the wrong places.

A. Feild has a lot of cool work to her credit. If anyone else is interested, here is the search results at the site makc lead us to...
http://hubblesite.org/search/index.php?query=Feild

[makc]

Author: A. Feild (Space Telescope Science Institute)

I runned advanced search Her (!) full name is Ann Feild Didyk, she is Senior Graphic Designer at STSI (obviously). You could even find her phone and email here, as of Jul. 13, 2006.

[apodman]

STSI

They prefer "STScI" - it's much snazzier, though totally arbitrary as far as I can see.

[peate]

You know, I think it's cheese, Gromitt.

Doesn't it look more like a big head of cheese than a giant egg?

The moons look like eggs though, especially the right one.

I've just joined but I''ve been a daily viewer for many years and I always enjoy the day's picture, but that dancing fella was definitively something else.

Cheers

[bstout]

I confess I don't understand jesusfreak's and bystander's responses to my earlier post. I was pointing out that when you go to the APOD main page, and click on the picture, you get this picture: http://antwrp.gsfc.nasa.gov/apod/image0 ... sa_big.jpg which lists the old designations of the Kuiper Belt Objects. I noticed this because I use APOD as my background screen.

I thought that the powers that be would have wanted to post the updated version of the picture, with the actual names Eris, Makemake and Haumea. You can see that picture by following the hyperlink to the Wikipedia article on Haumea. Since I have seen APOD pictures updated during the day they were posted on other occasions, I thought that an early notice might let someone have a chance to change this picture on the APOD website.


On another note, the title of my post -- before it was merged in -- was:

Wrong picture for "Largest Known Kuiper Belt Objects&qu

I tried editing out the '&qu' out of the title, but the system kept replacing the final double quote with '&qu'. Is there someplace to report bugs?

Thanks!

[apodman]

I tried editing out the '&qu' out of the title, but the system kept replacing the final double quote with '&qu'. Is there someplace to report bugs?

Once again I think this is an issue with phpBB which is beyond the usual realm of those who use the canned phpBB software product to run their forum.

It appears that the truncation of the title to a maximum length takes place at an inappropriate time (after punctuation that needs to be escaped is temporarily converted to a character code and before it is converted back). The truncated code at the end of the title is not valid and is not converted back. I'd try the phpBB blog to start my search to see where to submit my trouble ticket. What I would really do is be a sheep, accept the ground rules even though I don't appreciate them, and avoid using punctuation I'm not sure of at the end of long titles.

[bystander]

I confess I don't understand jesusfreak's and bystander's responses to my earlier post.

I suspect jesusfreak was providing a link to the original APOD and Pic, as a courtesy to future readers.

I was searching for more info on the pic you provided and found your pic with links to info about the individual TNOs and thought others may be interested.

Neither, in the strictest sense, were meant as a reply to your post. Generally, if I'm responding to a question or statement you make, I'll quote it as I did here.

Welcome to Asterisk!

[emc]

Author: A. Feild (Space Telescope Science Institute)

I runned advanced search Her (!) full name is Ann Feild Didyk, she is Senior Graphic Designer at STSI (obviously). You could even find her phone and email here, as of Jul. 13, 2006.

Thanks again makc for your good detective work! I emailed Ann asking her for a link to her website and she politely responded below...

<<"I work with the folks who manage the Hubble Space Telescope but also do work of a more whimsical sort. I used to be featured on the Folio Planet site but am now with AltPick.com:

http://altpick.com/annfeilddidyk

I use a combination of Adobe Illustrator and Photoshop (CS3 for now) for most of my artwork, and I often start with a scanned pencil rough.

I build textures and layers of light to get a luminescent look.

Thank you for you interest! Please check out the Hubble's website at:

http://hubblesite.org
http://hubblesite.org/newscenter

Best,

Ann">>

[makc]

I think "Starcatcher" is her self-portrait.

[emc]

I think "Starcatcher" is her self-portrait.

That's what I thought too... I will ask.

My favorite in her whimsical gallery so far is "Star party". I wonder if she is in the center toasting the stars.

I believe you can learn something about every artist within the confines of their private works (non-commercial). Work that is done for the sake of art. Sometimes easy to see, sometimes hidden. The same is true of writing.

I hope others also enjoyed learning a bit more about the author of this APOD.