Wednesday, December 4, 2013

The Asteroid Vesta—‘old’ yet ‘young’!

from here
NASA, JPL-caltech, UCLA, MPS,DLR, IDA
Asteroid-Vesta
NASA’s robotic spacecraft ‘Dawn’, launched in 2007 to go to the asteroid belt between Mars and Jupiter, has now orbited around Vesta—second largest of the asteroids. And it’s sent back eye-popping photos and other data that have shocked and surprised scientists, to say the least.
For example, Vesta has a south polar mountain three times the height of Everest. Twenty-one kilometres (13 miles) higher than the surrounding terrain, it is one of the largest mountains in the solar system,1 yet stands on a body smaller in width than Texas. Why should Vesta have such “surprisingly complex”2 structural features, compared to other asteroids?

However, with its equatorial troughs and other large impact basins, Vesta had another surprise reminiscent of some of the outer-planet moons like Enceladus and Miranda: parts that look ‘old’, and parts that look ‘young’!

The northern half of Vesta, seen on the upper left of the photo here, appears to show some of the densest cratering in the solar system, while the southern half is “unexpectedly smooth”.3 That’s because—according to uniformitarian assumptions about meteorite impacts—the greater the number of craters, the greater the age. But why then is the southern half not as pock-marked—even “smooth”? As Science Daily headlined it, “Massive Mountains, Rough Surface, and Old-Young Dichotomy in Hemispheres.”2 Our own moon has a similar asymmetry in cratering. Astronomer Danny Faulkner suggests that instead of bombardment over millions of years, most craters were caused by a narrow, intense, but brief swarm of impactors that passed by before the moon had moved very far in a single orbit, perhaps during the year of the Flood.4 A similar explanation could apply to Vesta.
Perhaps planetary scientists may have to concoct a new word like yold for this oxymoronic dichotomy. It’s yet another example of the contradictory evidence and problems inherent in using crater density, or any other feature observable at present, to guess the unobservable past history of the bodies in our solar system. Such ‘dating’ methods don’t work5—only a true eyewitness account of the asteroid’s origin can definitively provide its age.

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References and notes

  1. It is just 3 km (2 miles) shy of the record holder on Mars, Olympus Mons. Return to text.
  2. Dawn at Vesta: Massive Mountains, Rough Surface, and Old-Young Dichotomy in Hemispheres, Science Daily, www.sciencedaily.com/releases/2011/10/111003093344.htm, 3 October 2011. Return to text.
  3. Nemiroff, R. and Bonnell, J., Astronomy picture of the day—2 August 2011, apod.nasa.gov/apod/ap110802.html. Return to text.
  4. Faulkner, D., A biblically-based cratering theory, J. Creation 13(1):100–104, 1999; creation.com/cratering; Spencer, W.R., Response to Faulkner’s biblically-based cratering theory , J. Creation 14(1):46–49, 2000; creation.com/crateringresponse. Return to text.
  5. Coppedge, D., Young Saturn, Creation 33(3):44–46, 2011. Return to text.

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