![]() Radar image of Icarus taken by the Goldstone Observatory in June 2015 | |
Discovery [1] | |
---|---|
Discovered by | W. Baade |
Discovery site | Palomar Obs. |
Discovery date | 27 June 1949 |
Designations | |
(1566) Icarus | |
Pronunciation | /ˈɪkərəs/ [2] |
Named after | Icarus [3] (Greek mythology) |
1949 MA | |
Adjectives | Icarian /aɪˈkɛəriən/ [5] |
Symbol | ![]() |
Orbital characteristics [4] | |
Epoch 1 July 2021 (JD 2459396.5) | |
Uncertainty parameter 0 | |
Observation arc | 72.11 yr (26,339 d) |
Aphelion | 1.9697 AU |
Perihelion | 0.1865 AU |
1.0781 AU | |
Eccentricity | 0.8270 |
1.12 yr (409 d) | |
180.73° | |
0° 52m 49.8s / day | |
Inclination | 22.812° |
87.981° | |
31.419° | |
Earth MOID | 0.0341 AU (13.3 LD) |
Physical characteristics | |
Dimensions | 1.61 km × 1.60 km × 1.17 km [6] |
16.35 [1] [4] | |
1566 Icarus ( /ˈɪkərəs/ IK-ə-rəs; provisional designation : 1949 MA) is a large near-Earth object of the Apollo group and the lowest numbered potentially hazardous asteroid. [20] It has an extremely eccentric orbit (0.83) and measures approximately 1.4 km (0.87 mi) in diameter. In 1968, it became the first asteroid ever observed by radar. [3] Its orbit brings it closer to the Sun than Mercury and further out than the orbit of Mars, which also makes it a Mercury-, Venus-, and Mars-crossing asteroid. This stony asteroid and relatively fast rotator with a period of 2.27 hours was discovered on 27 June 1949, by German astronomer Walter Baade at the Palomar Observatory in California. [1] It was named after the mythological Icarus. [3]
Icarus orbits the Sun at a distance of 0.19–1.97 AU once every 13 months (409 days; semi-major axis of 1.08 AU). Its orbit has an eccentricity of 0.83 and an inclination of 23° with respect to the ecliptic. [4] The body's observation arc begins with its official discovery observation at Palomar in 1949. [1]
At perihelion, Icarus comes closer to the Sun than Mercury, i.e. it is a Mercury-crossing asteroid. It is also a Venus and Mars-crosser. From 1949 until the discovery of 3200 Phaethon in 1983, it was known as the asteroid that passed closest to the Sun. Since then hundreds of Mercury-crossers have been found, the closest ones are now being 2005 HC4 and (394130) 2006 HY51 (also see List of Mercury-crossing minor planets § List).
Icarus is thought to be the source of the Arietids, [21] a strong daylight meteor shower. However other objects such as the short-period Sun-grazing comet 96P/Machholz are also possible candidates for the shower's origin. [22]
Icarus has an Earth minimum orbital intersection distance of 0.0352 AU (5,270,000 km ), which translates into 13.7 lunar distances (LD). [4] This near-Earth object and potentially hazardous asteroid makes close approaches to Earth in June at intervals of 9, 19, or 28 years.
On 14 June 1968, it came as close as 0.042482 AU (6,355,200 km ; 16.533 LD ). [23] During this approach, Icarus became the first minor planet to be observed using radar, with measurements obtained at the Haystack Observatory [24] and the Goldstone Tracking Station. [25]
The last close approach was on 16 June 2015, when Icarus passed Earth at 0.05383 AU (8,053,000 km; 20.95 LD). [6] [23] Before that, the previous close approach was on 11 June 1996, at 0.10119 AU (15,138,000 km), almost 40 times as far as the Moon. The next notably close approach will be on 13 June 2043, at 0.0586 AU (8,770,000 km) from Earth. [23]
This minor planet was named after Icarus, son of Daedalus (also see 1864 Daedalus) from Greek mythology. They attempted to escape prison by means of wings constructed from feathers and wax. Icarus ignored his father's instructions not to fly too close to the Sun. When the wax in his wings melted he fell into the sea and drowned. [3] The naming was suggested by R. C. Cameron and Dr. Folkman. The official naming citation was published by the Minor Planet Center in January 1950 ( M.P.C. 347). [26] Both mythological figures are honored with the lunar craters Icarus and Daedalus . [3]
Radiometric observation characterized Icarus as a stony S-type and Q-type asteroid. [19]
Since 1968, several rotational lightcurves of Icarus were obtained from photometric and radiometric observations. [10] [13] [14] During the asteroid's close approach in June 2017, observations of the fast-moving object were taken by Italian astronomers Virginio Oldani and Federico Manzini, Brian Warner at the Palmer Divide Station ( U82 ) in California, and by Australian astronomers at the Darling Range and Blue Mountains Observatories ( Q68 ). [11] [12] [15] [b]
Lightcurve analysis gave it a consolidated rotation period of 2.2726 hours with a brightness variation of 0.22 magnitude ( U=3 ). [18] [b] Icarus is a relatively fast rotator, near the threshold where non-solid rubble piles fly apart.
Analysis of 2015 radar observations obtained at the Arecibo Observatory and the Goldstone Observatory yields a spin axis of (270.0°, −81.0°) in ecliptic coordinates (λ, β). [6]
According to several radiometric, photometric, and radar observations, including the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Icarus measures between 1.0 and 1.44 kilometers in diameter and its surface has an albedo between 0.14 and 0.51. [7] [8] [9] [6] [16] [a]
Analysis of the radar data obtained at the Arecibo and Goldstone observatories in June 2015 gives the body's dimensions: 1.61 × 1.60 × 1.17 kilometers, with equivalent diameter of 1.44 kilometers. [6] The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.14 based on the radar-derived equivalent diameter of 1.44 kilometers and absolute magnitude of 16.96. [18]
Icarus is being studied to better understand general relativity, solar oblateness, and Yarkovsky drift. [27] [28] In its case, the perihelion precession caused by general relativity is 10.05 arcseconds per Julian century. [27] [28]
"Project Icarus" was a student project conducted at the Massachusetts Institute of Technology (MIT) in the spring of 1967 as a contingency plan in case of an impending collision with 1566 Icarus.
This project was an assignment by Paul Sandorff for his group of MIT systems engineering graduate students to devise a plan to use rockets to deflect or destroy Icarus in the case that it was found to be on a collision course with planet Earth. [29] [30] [31] Time magazine ran an article on the endeavor in June 1967 [30] and the following year the student report was published as a book. [29] [31] [32]
The students' plan relied on the new Saturn V rocket, which did not make its first flight until after the report had been completed. During the course of their study, the students visited the Kennedy Space Center, Florida, where they were so impressed with the Vehicle Assembly Building that they wrote of "the awesome reality" that had "completely erased" their doubts over using the technology associated with the Apollo program and Saturn rockets.
The final plan hypothesized that six Saturn V rockets (appropriated from the then-current Apollo program) would be used, each launched at variable intervals from months to hours away from impact. Each rocket was to be fitted with a single 100-megaton nuclear warhead as well as a modified Apollo Service Module and uncrewed Apollo Command Module for guidance to the target. The warheads would be detonated 30 meters from the surface, deflecting or partially destroying the asteroid. Depending on the subsequent impacts on the course or the destruction of the asteroid, later missions would be modified or cancelled as needed. The "last-ditch" launch of the sixth rocket would be 18 hours prior to impact. [33]
The Project Icarus report later served as the basis and inspiration for the 1979 science fiction film Meteor . [31] [34]
"Summertime on Icarus" is a science fiction short story by British writer Arthur C. Clarke.
1620 Geographos is a highly elongated, stony asteroid, near-Earth object and potentially hazardous asteroid of the Apollo group, with a mean diameter of approximately 2.5 km (1.6 mi). It was discovered on 14 September 1951, by astronomers Albert George Wilson and Rudolph Minkowski at the Palomar Observatory in California, United States. The asteroid was named in honor of the National Geographic Society.
1036 Ganymed, provisional designation 1924 TD, is a stony asteroid on a highly eccentric orbit, classified as a near-Earth object of the Amor group. It was discovered by German astronomer Walter Baade at the Bergedorf Observatory in Hamburg on 23 October 1924, and named after Ganymede from Greek mythology. With a diameter of approximately 35 kilometers, Ganymed is the largest of all near-Earth objects but does not cross Earth's orbit. The S-type asteroid has a rotation period of 10.3 hours. In October 2024, it is predicted to approach Earth at a distance of 56,000,000 km; 35,000,000 mi (0.374097 AU).
4197 Morpheus, provisional designation 1982 TA, is a highly eccentric asteroid and near-Earth object of the Apollo group, approximately 3 kilometers in diameter. It was discovered on 11 October 1982, by American astronomers Eleanor Helin and Eugene Shoemaker at Palomar Observatory in California, United States. The asteroid was later named for Morpheus from Greek mythology.
4486 Mithra, is an eccentric asteroid and suspected contact-binary, classified as near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter. It belongs to the Apollo group of asteroids and is a relatively slow rotator.
(53319) 1999 JM8 is an asteroid, slow rotator and tumbler, classified as a near-Earth object and potentially hazardous asteroid (PHA) of the Apollo group, approximately 7 kilometers (4 miles) in diameter, making it the largest PHA known to exist. It was discovered on 13 May 1999, by astronomers of the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico.
69230 Hermes is a sub-kilometer sized asteroid and binary system on an eccentric orbit, classified as a potentially hazardous asteroid and near-Earth object of the Apollo group, that passed Earth at approximately twice the distance of the Moon on 30 October 1937. The asteroid was named after Hermes from Greek mythology. It is noted for having been the last remaining named lost asteroid, rediscovered in 2003. The S-type asteroid has a rotation period of 13.9 hours. Its synchronous companion was discovered in 2003. The primary and secondary are similar in size; they measure approximately 810 meters (2,700 ft) and 540 meters (1,800 ft) in diameter, respectively.
(6178) 1986 DA is a metallic asteroid, classified as near-Earth object of the Amor group, approximately 3 kilometers in diameter. It was discovered on 16 February 1986, by Japanese astronomer Minoru Kizawa at Shizuoka Observatory, Japan.
3752 Camillo is an inclined contact-binary asteroid, classified as near-Earth object of the Apollo group, approximately 2.3 kilometers in diameter. It was discovered on 15 August 1985, by astronomers Eleanor Helin and Maria Barucci using a 0.9-metre (35 in) telescope at the CERGA Observatory in Caussols, France. Lightcurve studies by Petr Pravec in 1998 suggest that the assumed S-type asteroid has an elongated shape and a longer-than average rotation period of 38 hours.
(185851) 2000 DP107 is a sub-kilometer sized asteroid, classified as potentially hazardous asteroid and near-Earth object of the Apollo group that is notable because it provided evidence for binary asteroids in the near-Earth population. The PROCYON probe developed by JAXA and the University of Tokyo was intended to flyby this asteroid before its ion thruster failed and could not be restarted.
14827 Hypnos is a highly eccentric, sub-kilometer-sized carbonaceous asteroid that is thought to be an extinct comet. It is classified as near-Earth object and potentially hazardous asteroid of the Apollo group.
1916 Boreas, provisional designation 1953 RA, is an eccentric, stony asteroid and near-Earth object of the Amor group, approximately 3 kilometers in diameter. After its discovery in 1953, it became a lost asteroid until 1974. It was named after Boreas from Greek mythology.
3122 Florence is a stony trinary asteroid of the Amor group. It is classified as a near-Earth object and potentially hazardous asteroid. It measures approximately 5 kilometers in diameter. It orbits the Sun at a distance of 1.0–2.5 AU once every 2 years and 4 months ; the orbit has an eccentricity of 0.42 and an inclination of 22° with respect to the ecliptic. Florence has two moons.
5143 Heracles is a highly eccentric, rare-type asteroid and synchronous binary system, classified as near-Earth object of the Apollo group, approximately 4.8 kilometers in diameter. The asteroid was discovered on 7 November 1991, by American astronomer Carolyn Shoemaker at Palomar Observatory in California, United States. It is named for the Greek divine hero Heracles. It has an Earth minimum orbit intersection distance of 0.058 AU (8.7 million km) and is associated with the Beta Taurids daytime meteor shower.
7088 Ishtar, provisional designation 1992 AA, is a synchronous binary asteroid and near-Earth object from the Amor group, approximately 1.3 kilometers in diameter. It was discovered on 1 January 1992, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California. The relatively bright asteroid with an unknown spectral type has a rotation period of 2.7 hours. In December 2005, a 330-meter sized satellite was discovered, orbiting its primary every 20.65 hours.
3102 Krok, provisional designation 1981 QA, is a rare-type asteroid and slow rotator, classified as a near-Earth object of the Amor group, that measures approximately 1.5 kilometers in diameter.
12923 Zephyr (prov. designation:1999 GK4) is a stony asteroid, classified as potentially hazardous asteroid and near-Earth object of the Apollo group, approximately 2 kilometers (1.2 miles) in diameter. It was discovered on 11 April 1999, by astronomers of the Lowell Observatory Near-Earth Object Search at Anderson Mesa Station near Flagstaff, Arizona. The asteroid was named after the deity Zephyrus from Greek mythology.
(31345) 1998 PG is an eccentric, stony asteroid and binary system, classified as near-Earth object of the Amor group of asteroids, approximately 900 meters in diameter. It minor-planet moon, S/2001 (31345) 1, has an estimated diameter of 270 meters.
(66063) 1998 RO1 is a stony near-Earth object of the Aten group on a highly-eccentric orbit. The synchronous binary system measures approximately 800 meters (0.50 miles) in diameter. It was discovered by astronomers of the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, on 14 September 1998.
(436724) 2011 UW158, provisionally known as 2011 UW158, is a stony, walnut-shaped asteroid and fast rotator, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters in diameter. It was discovered on 25 October 2011, by Pan-STARRS at Haleakala Observatory on the island of Maui, Hawaii, in the United States.
(164121) 2003 YT1, provisional designation 2003 YT1, is a bright asteroid and synchronous binary system on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 2 kilometers (1.2 miles) in diameter. It was discovered on 18 December 2003, by astronomers with the Catalina Sky Survey at the Catalina Station near Tucson, Arizona, in the United States. The V-type asteroid has a short rotation period of 2.3 hours. Its 210-meter sized minor-planet moon was discovered at Arecibo Observatory in May 2004.