Astronomy:Amor asteroid

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Overview of all groups of Near-Earth Objects (NEOs)

The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor /ˈmɔːr/. 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),[1] 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).

Definition

Amor asteroid Eros visited by NEAR Shoemaker in 2000

The orbital characteristics that define an asteroid as being in the Amor group are:[2]

  • The orbital period is greater than one year; i.e., the orbital semi-major axis (a) is greater than 1.0 AU (a > 1.0 AU);
  • The orbit does not cross that of Earth; i.e., the orbital perihelion (q) is greater than Earth's orbital aphelion (q > 1.017 AU);
  • The object is a near-Earth object (NEO); i.e., q < 1.3 AU.

Populations

As of November 2023 there are 12,020 known Amor asteroids. Of those objects, 1275 are numbered and 80 are named.[3]

Outer Earth-grazer asteroids

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.

Potentially hazardous asteroids

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), and as of November 2023 70 Amors are classified as a PHA, the named objects 2061 Anza, 3122 Florence, 3908 Nyx, and 3671 Dionysus.[4]

Lists

Prominent Amor asteroids

Name Year Discoverer Refs
3908 Nyx 1980 Hans-Emil Schuster MPC · JPL · LCDB
1221 Amor 1932 Eugène Delporte MPC · JPL · LCDB
1036 Ganymed 1924 Walter Baade MPC · JPL · LCDB
887 Alinda 1918 Max Wolf MPC · JPL · LCDB
719 Albert 1911 Johann Palisa MPC · JPL · LCDB
433 Eros 1898 Gustav Witt MPC · JPL · LCDB

Named Amor asteroids

This is a non-static list of named Amor asteroids.[5]

Designation Prov. designation
433 Eros 1898 DQ
719 Albert 1911 MT
887 Alinda 1918 DB
1036 Ganymed 1924 TD
1221 Amor 1932 EA1
1580 Betulia 1950 KA
1627 Ivar 1929 SH
1915 Quetzalcoatl 1953 EA
1916 Boreas 1953 RA
1917 Cuyo 1968 AA
1943 Anteros 1973 EC
1980 Tezcatlipoca 1950 LA
2059 Baboquivari 1963 UA
2061 Anza 1960 UA
2202 Pele 1972 RA
2368 Beltrovata 1977 RA
2608 Seneca 1978 DA
3102 Krok 1981 QA
3122 Florence 1981 ET3
3199 Nefertiti 1982 RA
3271 Ul 1982 RB
3288 Seleucus 1982 DV
3352 McAuliffe 1981 CW
3551 Verenia 1983 RD
3552 Don Quixote 1983 SA
Designation Prov. designation
3553 Mera 1985 JA
3671 Dionysus 1984 KD
3691 Bede 1982 FT
3757 Anagolay 1982 XB
3908 Nyx 1980 PA
3988 Huma 1986 LA
4055 Magellan 1985 DO2
4401 Aditi 1985 TB
4487 Pocahontas 1987 UA
4503 Cleobulus 1989 WM
4947 Ninkasi 1988 TJ1
4954 Eric 1990 SQ
4957 Brucemurray 1990 XJ
5324 Lyapunov 1987 SL
5332 Davidaguilar 1990 DA
5370 Taranis 1986 RA
5620 Jasonwheeler 1990 OA
5653 Camarillo 1992 WD5
5751 Zao 1992 AC
5797 Bivoj 1980 AA
5863 Tara 1983 RB
5869 Tanith 1988 VN4
5879 Almeria 1992 CH1
6050 Miwablock 1992 AE
6456 Golombek 1992 OM
Designation Prov. designation
6569 Ondaatje 1993 MO
7088 Ishtar 1992 AA
7336 Saunders 1989 RS1
7358 Oze 1995 YA3
7480 Norwan 1994 PC
8013 Gordonmoore 1990 KA
8034 Akka 1992 LR
8709 Kadlu 1994 JF1
9172 Abhramu 1989 OB
9950 ESA 1990 VB
11284 Belenus 1990 BA
13553 Masaakikoyama 1992 JE
15745 Yuliya 1991 PM5
15817 Lucianotesi 1994 QC
16064 Davidharvey 1999 RH27
16912 Rhiannon 1998 EP8
18106 Blume 2000 NX3
20460 Robwhiteley 1999 LO28
21088 Chelyabinsk 1992 BL2
52387 Huitzilopochtli 1993 OM7
65803 Didymos 1996 GT
96189 Pygmalion 1991 NT3
154991 Vinciguerra 2005 BX26
162011 Konnohmaru 1994 AB1
164215 Doloreshill 2004 MF6
Designation Prov. designation
189011 Ogmios 1997 NJ6
452307 Manawydan 1997 XV11
481984 Cernunnos 2009 KL2

See also

References

External links