3361 Orpheus (1982 HR) is an

Apollo asteroid The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Earth ...

that was discovered on 24 April 1982 by Carlos Torres at Cerro El Roble Astronomical Station. Its eccentric orbit crosses that of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

and

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

, and approaches

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

as well. From 1900 to 2100 it passes closer than 30 Gm to Venus 11, Earth 33, and Mars 14 times. It passed by Earth at a distance of about in 1937, 1978, 1982, and 2021 and will again in 2025. 3361 Orpheus is a

potentially hazardous asteroid A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and is large enough to cause significant regional damage in the event of impact. They are ...

(PHA) because its

minimum orbit intersection distance Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits o ...

(MOID) is less than and its diameter is greater than 140 meters. The Earth-MOID is . With an

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

of 36 years, the orbit is well-determined for the next several hundred years. The orbital solution includes non-gravitational forces.

Missions

3361 Orpheus had been one of the originally proposed targets for the Near Earth Asteroid Rendezvous (NEAR) mission. The proposed

AIDA ''Aida'' (or ''Aïda'', ) is an opera in four acts by Giuseppe Verdi to an Italian libretto by Antonio Ghislanzoni. Set in the Old Kingdom of Egypt, it was commissioned by Cairo's Khedivial Opera House and had its première there on 24 Decemb ...

mission's spacecraft,

Double Asteroid Redirection Test Double Asteroid Redirection Test (DART) is a NASA space mission aimed at testing a method of planetary defense against near-Earth objects (NEOs). It was designed to assess how much a spacecraft impact deflects an asteroid through its transfe ...

was a fly-by observation of 3361 Orpheus during its trajectory to asteroid 65803 Didymos but later cancelled.

References

External links

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