The Most Spectacular Image of the Day, Science-Wise

On January 1 New Horizons encountered the Kuiper Belt object nicknamed Ultima Thule. Some 6.5 billion kilometers from the Sun, Ultima Thule is the most distant world ever explored by a spacecraft from Earth. This historic image, the highest resolution image released so far, was made at a range of about 28,000 kilometers only 30 minutes before the New Horizons closest approach. Likely the result of a gentle collision shortly after the birth of the Solar System, Ultima Thule is revealed to be a contact binary, two connected sphere-like shapes held in contact by mutual gravity. Dubbed separately by the science team Ultima and Thule, the larger lobe Ultima is about 19 kilometers in diameter. Smaller Thule is 14 kilometers across.

Nextbigfuture Commenter Goatguy Shares How Impressed He Is by the Ultima Thule Space Mission

To think.
Mankind has lobbed a space probe 6.5 BILLION kilometers off, and come within 3,000 km of this tiny contact binary. It just boggles the mind — well at least mine.

A pair of Kuiper Belt Objects (KBO’s), apparently “gently in contact”, very probably shortly after the formation of the nascent Solar System. Untouched. Oh… you can tell by looking that they have had their encounters with a few scathing impactors, but really, they’re pretty good looking for 4.5 billion years whizzing around the sun. Actually, more like “slowly cruising”, since their solar orbit is at 42 to 46 AU.

Using the formula, (period = AU to the 3/2 power), and geometric mean: M = sqrt( A * B ), we have

period = ((A * B) to the 1/2 power) to the 3/2 power
period = (A * B) to the 3/4 power.
period = (42 * 46) ^ (3/4)
period = 291 years

and to get orbital velocity, we have to use

velocity = [ 2π sqrt( 42 * 46 ) · 149.5e6 km/AU ] / (291 * 365.25 * 24 * 60 * 60)
velocity = 4.5 km/sec

By comparison, Earth is rather more “whizzing” around Sol, at 29.8 km/s.
Wouldn’t it be something to someday land on Ultima Thule (pronounced “UL-tim-uh, THOO-lee”)?

Also, its personal, but I’m as pleased as punch that the contact pair have been dubbed Ultimate (the larger) and Thule (the smaller). Cute.

Anyway, just more goatbits.


23 thoughts on “The Most Spectacular Image of the Day, Science-Wise”

  1. Mars already has ~3% nitrogen in its atmosphere, which is plenty for industrial uses.

    For terraforming, you’ll need a lot more than a few comets. You may be better off mining nitrogen from Titan’s atmosphere (it’s 98% nitrogen), and combining it with hydrogen from nearby Saturn to make your own pure ammonia comets. It’s much closer than the Kuiper belt. But this too would require titan efforts.

    However, the mean temperature on Mars is barely above the melting point of ammonia, so I wouldn’t be surprised to find ammonia ice and other nitrogen compounds near the poles and below the surface of Mars.

  2. I don’t care about landing on it – other than to perhaps hurl it at Mars. I bet it’s partly made of ammonia, and Mars needs nitrogen.

  3. How do they come up with those names?
    I wish I had such ability when playing sci fi games. Never can decide on ship names.

  4. See yesterday’s PBS NOVA show about New Horizons for a good look at what went into this. They even updated it with the pictures that came out just hours before the show aired.

  5. An intercept target existing on the path is one thing, finding it is another. The team at NASA was sweating it out trying to find a target in the right area with enough time to determine its orbital path for an intercept. The PBS NOVA show yesterday does a great job talking about that (and they even had the pictures from the flyby, so they must have been editing that episode just hours before it aired).

  6. I suppose I could fire a rifle round down an infinite plain, one teaming with a nearly infinite herd of elk, and eventually one “lucky” fellow will wander into an intercept path with the bullet.

    As a hunter, a kill is a kill. I can hardly wait for the feast that’ll be following this appetizer of a photo!

  7. True.

    But putting it in perspective, Ultima Thule is about as far from Pluto as Earth is from Jupiter (at out closest conjunction). … Which is to say QUITE a distance away.  

    And in such a distance, given the poorly known, but still statistically relevant distribution of KBOs, well … that there’d be an intercept opportunity somewhere on the path with a nudge or two, wasn’t really a million-to-one probability. More like 10 to 1 or better. Because the word “somewhere” (along the path) has a LOT of kilometers of potential interception.  In this case, nearly a billion of them. 

    Just saying,

  8. You’re right, the mission team always believed they’d get a second target to aim at, and prepared they were. But, it wasn’t a guarantee that a target would present itself. There’s where luck came into the picture.

    It’s true. We most often tell the story of the one-in-a-million chance event that happens, not the 999,999 times it doesn’t.

  9. Luck favours the prepared … mission profile.

    Deliberately build in flexibility to the controls and trajectory, and luck is more likely to occur.

    In the context of the Oumuamua discussion, I vaguely recall that in the original Rendezvous with Rama story, the rendezvous party was on an unrelated mission that was “lucky” enough to be able to match trajectories when the new mission appeared.

  10. By my calculations, the pair were orbiting their common center-of-gravity at about 3.5 days/orbit and about 1.8 m/s or so, just before touching. Slow enough that even the rub-impact would be slight. Like a “sanding off” if they hadn’t also come into tide-lock well before then.

  11. Impressive shot, but one taken from the vicinity of Pluto, not Earth.

    One thing I take from this is how common these cosmic clumps must be, even while being so widely dispersed; each object commanding as much space as does a solitary dust speck, as it floats through the coloured Sunlight of its’ own otherwise pristine cathedral.

    And what part luck had in New Horizons predetermined path, that it could continue on after Pluto, with a relatively small push, push from back home, to speed past a second target that no one even knew existed at the start of the probes journey.

  12. I think they must have been in orbit, which decayed to the point of contact. Because it would have taken a remarkably mild “impact” to leave them intact like that.

  13. Of course the orbital mechanics is quite impressive… It would be nice to read others’ discussion regarding the radio communications…

  14. Calling it “world” is being generous. There are asteroids bigger than that.

    Otherwise it really is an interesting one, due to its dual body composition, that seems to come from a very slow original dance between two separated bodies, gently approaching and caressing each other until becoming one.

    And I certainly hope humans will visit it one day, in a future never ending hegira towards the stars.


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