Monster impact leaves Mars lopsided

BEIJING, June 26 (Xinhuanet) -- Scientists in U.S. offered fresh evidence for the lopsided shape of Mars saying that a monster impact punched the red planet, leaving behind perhaps the largest gash on any heavenly body in the solar system, media reported Friday.

An asteroid or comet whacked Mars some 4 billion years ago, blasting away much of its northern crust and creating a giant hole over 40 percent of the surface, researchers said.

"The betting odds have gone up a lot in favor of the impact model," said Walter Kiefer, a staff scientist at the Lunar and Planetary Institute in Houston.

At present, Mars is double-faced with the southern hemisphere pockmarked and filled with ancient rugged highlands, and the northern part smoother and covered by low-lying plains.

Researchers believe there was a single giant blow and not several small hits because there's no evidence of other basins.

(Agencies)