Thursday, July 16, 2015

New Pluto Images Show The World Many Of Us Expected

Mountains on Pluto
One of recent images of Pluto taken near its equator showing mountains 11,000 ft. high.

The images we'd all been waiting for from New Horizons, those taken during the pass at a distance of 7,700 miles - surprised many  - but not all of us. I always expected to see a rugged terrain complete with mountains, although ice-covered, as opposed to the "giant snowball" or "iceball" model peddled for decades. Another astronomer, Dr. Kenneth Franklin - then Director of the Hayden Planetarium- also agreed with that take when we discussed the planet on his visit to Barbados in 1975. "Icy snowball"? Merely a "first approximation" that will be squelched "if we ever get there",  according to Dr. Franklin..

Dr. Franklin,  after giving a guest lecture at the Harry Bayley Observatory, was also asked a question on the possible future demotion of Pluto. The questioner wanted to know, given we knew so little about Pluto (Viking hadn’t even landed on Mars yet) whether a possible demotion, e.g. to an asteroid, might be in the works if we discovered it was much smaller than then believed. (At that time, it was presumed to be about 3600 miles in diameter or about the size of Mercury).

Franklin’s answer – which I captured on audiotape- was clear and distinct:

That depends. If someday it’s found that Pluto is only half as large as Mercury or even less, BUT if it’s found around the same time to have satellites of its own, then it is still a planet.”

Thus in one clear concise definition, Franklin disclosed how and why even a planet found to be much smaller than originally thought, can retain its status

Flashing forward, all the incoming photos of Pluto have been collected during the fly-by via two New Horizons'  cameras: LORRI (Long Range Reconnaissance Imager) , which takes black-and-white images, and "Ralph", which takes both panchromatic and color images. It will take nearly a year to get all the images back on account of the vast distance involved.

Because some of the color data returned from New Horizons is outside the spectrum the human eye can see, a team of Boulder-based Southwest Research Institute planetary scientists had to work overnight Monday to translate the latest image from LORRI into colors within our visible spectrum.

Incredibly, New Horizons' seven science instruments operate on a mere 200 watts, or about one-fifth the wattage of a standard household toaster — energy generated by a device called a Radioisotope Thermoelectric Generator. This low energy source also explains why the craft maintained radio silence (during the fly by) to conserve energy.

In the image shown above, we behold the most clear view of Pluto ever seen, revealing never-before-seen details of Pluto's surface. The image is at a resolution of 4 kilometers per pixel, or about 1,000 times better than what the best telescopes on Earth can see of the planet.

In the words of Southwest Research Institute's Alex Parker said from mission control Tuesday.

  "It's emotionally impactful to see the planet go from a flat planet in the distance to now seeing it. Somehow it just became a real place."

She was referring to the fact that  craters, peaks and ridges have now been revealed and there is evidence of surface impacts from space objects as well as evidence of current or previous tectonic activity. As one specialist put it:

"I think the biggest discovery for me is that Pluto has a complicated geological history. That's really basic information about Pluto that we had no idea about before yesterday ... Is it an ancient surface or a young surface? And now we see maybe it's both."

"Complicated geological history" generally means mountain  formation,  especially via the "folding process" associated with tectonic activity. In other words, Pluto's mountains are not simply two mile high ice packs. (In any case they'd never be able to support an estimated mass of 4 trillion kilograms!)

In addition, the fly by produced a spectacular image of Pluto's moon, Charon:

Charon shows a surface somewhat like our Moon but far less cratered, suggesting a much younger object.

Stay tuned!

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