CELESTIAL PAYOFF
Pluto images astound
Mankind’s first close- up look at Pluto did not disappoint Wednesday: The pictures showed ice mountains on Pluto about as high as the Rockies and canyons on its big moon Charon that appear deeper than those on Earth.
Especially astounding to scientists was the absence of craters in a zoom- in shot of Pluto, the dwarf planet that hosted its first visitor from Earth on Tuesday, NASA’s New Horizons spacecraft.
They said that suggests to their surprise that Pluto is geologically active even now and is being sculpted not by outside forces but by internal heat.
The long- awaited images were unveiled Wednesday in Maryland, home to mission operations for NASA’s New Horizons spacecraft.
“I don’t think any one of us could have imagined that it was this good of a toy store,” principal scientist Alan Stern said at a news conference. He marvelled: “The Pluto system is something wonderful.”
Added Lowell Observatory’s Will Grundy: “This is what we came for.”
“This exceeds what we came for,” corrected deputy project scientist Cathy Olkin.
The zoom- in of Pluto, showing an approximately 240- kilometre swath of the planet, reveals a mountain range about 3,350 metres high and tens of kilometres wide. John Spencer, a planetary scientist at Southwestern Research Institute, said the mountains appeared to be formed from Pluto’s icy bedrock.
The canyons on Charon look to be five kilometres to nine kilometres deep.
The images were collected as New Horizons swept within 12,000 kilometres of Pluto on Tuesday, becoming Pluto’s first visitor in its 4.5 billion- year existence.
Scientists didn’t know until Tuesday night — when the spacecraft phoned home — that the encounter was a success.
New Horizons already is 1.6 million kilometres beyond the dwarf planet, and 4.8 billion miles from Earth.
Travelling at more than 48,000 km/ h, New Horizons — the size of a baby grand piano — is the fastest spacecraft ever launched. At about $ 700 million, it was a modest expense by spacefaring standards.
And its measurements may yet yield crucial clues about how the early solar system evolved and how life began on Earth.
The journey began 9 ½ years ago, back when Pluto was still considered a full- fledged planet. The U. S. is now the only country to have visited every planet in the solar system ( Pluto’s unconscionable downgrading to a “dwarf planet” notwithstanding).
New Horizons is also expected to observe Pluto’s four little moons. It will take until late 2016 for all the data to reach Earth.
New Horizons already has confirmed that Pluto is, indeed, the King of the Kuiper Belt. New measurements it made show that Pluto is 2,370 kilometres in diameter, or about 80 kilometres bigger than estimated.
That’s still puny by solar- system standards. Pluto is just two- thirds the size of Earth’s moon. But it is big enough to be the largest object in the Kuiper Belt, a zone rife with comets and tens of thousands of other small bodies.
I don’t think any one of us could have imagined that it was this good of a toy store.