Plutonic Star Tar!

There comes a time when words fail, and all you can do is stare in amazement. The Friday press conference from the New Horizons team had that effect on many of us. (I’m not the only one who wept with sheer joy.)

Pluto haze

From behind the planet, the Sun illuminates Pluto’s 100 mi layer of haze.

They say pictures are worth thousands of words, so I’ll let the pictures do most of the talking (click on any image to go to the source)…

These images come from Friday’s press conference. See the July 24 Press Conference page at NASA for the source of these images and words to go along with them. I’m just too… impressed… by them to say much (and if you know me, you know how rare that is).

I’m in my own haze!

Pluto hi rez
The above looks like the image we got before New Horizons began its passby of Pluto, but it has twice the resolution of the July 13 image. Both use color data to create an image of Pluto as it really looks.

Pluto ices
The above false color image shows the complexity of Pluto’s surface. The different colors represent different chemistry. Different kinds of ices as well as the tholins (dark red stuff).

The image shows how the two halves of Pluto’s “heart” (Tombaugh Regio) are geologically distinct. The left half has been named Sputnik Planum.

Pluto ice plains
Above is a closeup of the northern edge of Sputnik Planum showing how the (exotic) ices have flowed into the rougher region. It’s thought possible that the region is a source of those ices (nitrogen ice, carbon monoxide ice, but not water ice, which is too hard at Pluto’s temps).

Pluto south plain
Above is a closeup of the southern edge of Sputnik Planum also showing the flow of exotic ices (note how the crate just below the center of the image has filled with ices) as well as a bit of the dark tholin-rich region.

We’ve certainly come a long way from this Hubble image of Pluto:

Pluto Hubble

You might be asking, so exactly what are tholins? Read this blog post, What in the world(s) are tholins?, for an excellent description. I do want to mention that tholins are due, in large part, to the inestimable Carl Sagan.

Below I quote the linked blog post quoting Carl Sagan and Bishun Khare from their article in Nature, January 11, 1979…

For the past decade we have been producing in our laboratory a variety of complex organic solids from mixtures of the cosmically abundant gases CH4, C2H6, NH3, H2O, HCHO, and H2S. The product, synthesized by ultraviolet (UV) light or spark discharge, is a brown, sometimes sticky, residue, which has been called, because of its resistance to conventional analytical chemistry, “intractable polymer”.

However, we have recently succeeded, through sequential and non-sequential pyrolysis followed by gas chromatography-mass spectrometry (GC-MS) in determining something of the composition of this material. It is clearly not a polymer—a repetition of the same monomeric unit—and some other term is needed.

We have discussed this material as a constituent of the Earth’s primitive oceans and therefore as relevant to the origin of life; as a component of red aerosols in the atmospheres of the outer planets and Titan; as present in comets, carbonaceous chondrites, and pre-planetary solar nebulae; and as a major constituent of the interstellar medium, which is the concept discussed here.

We propose, as a model-free descriptive term, ‘tholins’ (Gk ϴὸλος, muddy; but also ϴoλòς, vault or dome), although we were tempted by the phrase ‘star-tar’. The properties of tholins will depend on the energy source used and the initial abundances of precursors, but a general physical and chemical similarity among the various tholins is evident.

-Carl Sagan and Bishun Khare, 1979, “Tholins: organic chemistry of interstellar grains and gas”, Nature, Vol 277, 11 January 1979

Note: The original was one paragraph. I added paragraphs to make reading easier. Also, I highlighted ‘star-tar’ because I really wish they’d called it that! Also, it’s been observed that: “tholins” … “the origin of life” … coincidence? Yeah, probably, but still.

If you’re into the whole Pluto thing, and you’re not already, you should be reading Emily Lakdawalla’s outstanding blog on The Planetary Society blog site. Definitely one of the best blogs on Pluto out there.

Me, I’m just speechless. (Hey. For me, this is speechless!)

Stay hazy my friends!

About Wyrd Smythe

The canonical fool on the hill watching the sunset and the rotation of the planet and thinking what he imagines are large thoughts. View all posts by Wyrd Smythe

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