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#### Trivia: Asteroid 2004 MN4

This Code-Doku is a trivia question about the asteroid formerly known as 2004 MN4. This object will come so close to the Earth in 2029 that it will be visible with the naked eye. Although this is a good topic for a trivia question in late 2005, it was a much more serious matter earlier this year.

This asteroid will pass approximately 36,200 km from the center, or approximately 30,000 km from the surface of the Earth. This might seem like a safe distance (and it is), but it was a wake-up call for many people who hadn't taken the threat of an asteroid collision seriously. It took a lot of careful observation to determine that this asteroid would not hit the Earth in 2029. In fact, the area of the Earth as a target is about 3% of the area of a 36,000 km circle. In other words, about 3% of the asteroids passing this close to the Earth would actually hit us. Since this asteroid is about one-third of a kilometer in diameter, coming in at about 12.5 km/s, it would cause a devastating amount of damage—no matter where it hit.

Because the orbit is extremely well known, this asteroid has been numbered and named. That number and name form the hidden message in this code-doku.

Place each of the characters in SOPHIA 249 exactly once in each row, column and 3×3 box. When you have completed the puzzle, one of the shaded diagonals will form the number and the other will form the name of the asteroid formerly known as 2004 MN4. (The name is not Sophia.)

Difficulty: Tough

Here is a print-friendly version of this puzzle.