Definition 2
An asteroid belongs to the Amor group if:
1. Its orbital period is greater than one year. This is equivalent to saying that its semi-major axis (a) is greater than 1.0 AU. Mathematically, a > 1.0 AU.
2. Its orbit doesn't cross Earth's orbit. That is, its lowest point (perihelion distance q) is higher than Earth's highest point (aphelion distance 1.017 AU). Mathematically, q > 1.017 AU.
3. It's a near-Earth object (NEO), that is, its perihelion distance q < 1.3 AU.
In summary, a > 1.0 AU and 1.017 AU < q < 1.3 AU.
While the above is the definition given in the source, the a > 1.0 AU constraint isn't necessary because if the perihelion distance q is greater than 1.017 AU, then the semi-major axis a will also be greater than 1.017 AU (and greater than 1.0 AU).
Read more about this topic: Amor Asteroid
Famous quotes containing the word definition:
“The definition of good prose is proper words in their proper places; of good verse, the most proper words in their proper places. The propriety is in either case relative. The words in prose ought to express the intended meaning, and no more; if they attract attention to themselves, it is, in general, a fault.”
—Samuel Taylor Coleridge (1772–1834)