Amor asteroid

The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor. The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth (i.e., the objects do not cross Earth's orbit), with most Amors crossing the orbit of Mars. The Amor asteroid 433 Eros was the first asteroid to be orbited and landed upon by a robotic space probe (NEAR Shoemaker). The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor. The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth (i.e., the objects do not cross Earth's orbit), with most Amors crossing the orbit of Mars. The Amor asteroid 433 Eros was the first asteroid to be orbited and landed upon by a robotic space probe (NEAR Shoemaker). The orbital characteristics that define an asteroid as being in the Amor group are: As of 2019 there are 7427 known Amor asteroids. 1153 are numbered, and 75 of them are named. An outer Earth-grazer asteroid is an asteroid that is normally beyond Earth's orbit, but which can get closer to the Sun than Earth's aphelion (1.0167 AU), and not closer than Earth's perihelion (0.9833 AU); i.e., the asteroid's perihelion is between Earth's perihelion and aphelion. Outer Earth-grazer asteroids are split between Amor and Apollo asteroids. Using the definition of Amor asteroids above, 'Earth grazers' that never get closer to the Sun than Earth does (at any point along its orbit) are Amors, whereas those that do are Apollos. To be considered a potentially hazardous asteroid (PHA), an object's orbit must, at some point, come within 0.05 AU of Earth's orbit, and the object itself must be sufficiently large/massive to cause significant regional damage if it impacted Earth. Most PHAs are either Aten asteroids or Apollo asteroids (and thus have orbits that cross the orbit of Earth), but approximately one tenth of PHAs are Amor asteroids. A potentially hazardous Amor asteroid therefore must have a perihelion of less than 1.05 AU. Approximately 20% of the known Amors meet this requirement, and about a fifth of those are PHAs. The fifty known Amor PHAs include the named objects 2061 Anza, 3122 Florence, 3908 Nyx, and 3671 Dionysus. This is a non-static list of named Amor asteroids.