Discovery [1] | |
---|---|
Discovered by | Pan-STARRS |
Discovery date | 10 October 2015 |
Designations | |
2015 TB145 | |
Orbital characteristics [2] | |
Epoch 31 May 2020 (JD 2459000.5) | |
Uncertainty parameter 0 | |
Observation arc | 3.11 yr (1,137 d) |
Aphelion | 3.9073 AU |
Perihelion | 0.2941 AU |
2.1007 AU | |
Eccentricity | 0.86002 |
3.04 yr (1,112.1 d) | |
121.744° | |
0° 19m 25.364s / day | |
Inclination | 39.6899° |
37.698° | |
121.744° | |
Earth MOID | 0.00295731 AU (442,407 km) |
Jupiter MOID | 2.41052 AU |
TJupiter | 2.97 |
Physical characteristics | |
Dimensions | |
0.06 [5] | |
20.0 [2] [6] | |
2015 TB145 is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 650 meters (2,000 feet) in diameter. [3] It safely passed 1.27 lunar distances from Earth on 31 October 2015 at 17:01 UTC, [7] and passed by Earth again in November 2018.
The asteroid was first observed on 10 October 2015 by Pan-STARRS at an apparent magnitude of 20 using a 1.8-meter (71 in) Ritchey–Chrétien telescope. [1] [6] [lower-alpha 1] The asteroid was not discovered sooner because it spends most of its time beyond the orbit of Mars, has a large orbital inclination, and is usually well below the plane of the ecliptic. [9] The asteroid last passed within 0.064 AU (9,600,000 km ; 5,900,000 mi ) of Earth on 29 October 1923 and will not pass that close again until 1 November 2088. [7]
The media has nicknamed the asteroid the "Great Pumpkin" [10] after the animated Halloween television special It's the Great Pumpkin, Charlie Brown , [11] "Spooky", [12] the "Halloween Asteroid", [13] [14] and the "Skull Asteroid" [11] due to its skull-like appearance following radio frequency images taken at Arecibo Observatory and closest approach coincidentally occurring on Halloween day. [11]
On 31 October 2015 the asteroid passed 0.00191 AU (286,000 km ; 178,000 mi ) from the Moon and then passed 0.00325 AU (486,000 km; 302,000 mi) from Earth. [7]
The last approach this close by an object with absolute magnitude brighter than 20 was 2004 XP14 on 3 July 2006 at 1.1 lunar distances. The next object this large known to pass this close to Earth is (137108) 1999 AN10 that will pass about 1 lunar distance from Earth on 7 August 2027. [15] It is estimated that there are about 2400 near-Earth asteroids 300–500 meters in diameter, of which about 1100 have been discovered. [16]
During closest approach to Earth the asteroid reached about apparent magnitude 10, [17] which is much too faint to be seen by the naked eye. Even at peak brightness, the asteroid was a challenging target for amateur astronomers with small telescopes, best seen in the Northern hemisphere. The glare from an 80% waning gibbous Moon also hindered observations.[ citation needed ]
At 11:00 UT the asteroid was in the constellation of Taurus about 9 degrees from the Moon and moving at a rate of 3.4 degrees per hour. [17] At the time of closest approach of 17:00 UT the asteroid was in the constellation of Ursa Major about 56 degrees from the Moon and moving at a rate of 14.7 degrees per hour. [17] After closest approach it quickly became too faint and too close to the Sun in the sky to be seen. [15]
PHA | Date | Approach distance in lunar distances | Abs. mag ( H ) | Diameter (C) (m) | Ref (D) | ||
---|---|---|---|---|---|---|---|
Nominal(B) | Minimum | Maximum | |||||
(152680) 1998 KJ9 | 1914-12-31 | 0.606 | 0.604 | 0.608 | 19.4 | 279–900 | data |
(458732) 2011 MD5 | 1918-09-17 | 0.911 | 0.909 | 0.913 | 17.9 | 556–1795 | data |
(163132) 2002 CU11 | 1925-08-30 | 0.903 | 0.901 | 0.905 | 18.5 | 443–477 | data |
69230 Hermes | 1937-10-30 | 1.926 | 1.926 | 1.927 | 17.5 | 700-900 [18] | data |
69230 Hermes | 1942-04-26 | 1.651 | 1.651 | 1.651 | 17.5 | 700-900 [18] | data |
2017 NM6 | 1959-07-12 | 1.89 | 1.846 | 1.934 | 18.8 | 580–1300 | data |
(27002) 1998 DV9 | 1975-01-31 | 1.762 | 1.761 | 1.762 | 18.1 | 507–1637 | data |
2002 NY40 | 2002-08-18 | 1.371 | 1.371 | 1.371 | 19.0 | 335–1082 | data |
2004 XP14 | 2006-07-03 | 1.125 | 1.125 | 1.125 | 19.3 | 292–942 | data |
2015 TB145 | 2015-10-31 | 1.266 | 1.266 | 1.266 | 20.0 | 620-690 | data |
(137108) 1999 AN10 | 2027-08-07 | 1.014 | 1.010 | 1.019 | 17.9 | 556–1793 | data |
(153814) 2001 WN5 | 2028-06-26 | 0.647 | 0.647 | 0.647 | 18.2 | 921–943 | data |
99942 Apophis | 2029-04-13 | 0.0981 | 0.0963 | 0.1000 | 19.7 | 310–340 | data |
2017 MB1 | 2072-07-26 | 1.216 | 1.215 | 2.759 | 18.8 | 367–1186 | data |
2011 SM68 | 2072-10-17 | 1.875 | 1.865 | 1.886 | 19.6 | 254–820 | data |
(163132) 2002 CU11 | 2080-08-31 | 1.655 | 1.654 | 1.656 | 18.5 | 443–477 | data |
(416801) 1998 MZ | 2116-11-26 | 1.068 | 1.068 | 1.069 | 19.2 | 305–986 | data |
(153201) 2000 WO107 | 2140-12-01 | 0.634 | 0.631 | 0.637 | 19.3 | 427–593 | data |
(276033) 2002 AJ129 | 2172-02-08 | 1.783 | 1.775 | 1.792 | 18.7 | 385–1242 | data |
(290772) 2005 VC | 2198-05-05 | 1.951 | 1.791 | 2.134 | 17.6 | 638–2061 | data |
(A) This list includes near-Earth approaches of less than 2 lunar distances (LD) of objects with H brighter than 20. (B) Nominal geocentric distance from the center of Earth to the center of the object (Earth has a radius of approximately 6,400 km). (C) Diameter: estimated, theoretical mean-diameter based on H and albedo range between X and Y. (D) Reference: data source from the JPL SBDB, with AU converted into LD (1 AU≈390 LD) (E) Color codes: unobserved at close approach observed during close approach upcoming approaches |
After it had been unobservable for almost three years, 2015 TB145 was recovered on 7 October 2018 by L. Buzzi at Schiaparelli Observatory (observatory code 204), at apparent magnitude 21. [19]
The 11 November 2018 flyby was about 0.267 AU (39,900,000 km ; 24,800,000 mi ) from Earth. [7] [20]
The close approach was studied with radar using Goldstone, the Green Bank Telescope, [15] and the Arecibo Observatory. It was one of the best radar targets of the year with a resolution as high as 2 meters (7 ft) per pixel. [15] Bistatic radar images created with the Green Bank Telescope had a resolution of 4 meters (13 ft) per pixel. [21] Arecibo images had a resolution of 7.5 meters (25 ft) per pixel. [5]
30 October | 31 October 12:55–13:08 UTC | 1 November |
---|---|---|
The high orbital inclination and eccentricity suggest 2015 TB145 may be an extinct comet that has shed its volatiles after numerous passes around the Sun. [5] [22] Orbital calculations by Petrus Jenniskens and Jérémie Vaubaillon showed that it was not expected to produce associated meteors in 2015. [23] Any meteoroids were expected to pass more than 0.0007 AU (100,000 km; 65,000 mi) from Earth's orbit. [23]
If meteoroids related to this asteroid were to cross Earth's path, the radiant is expected to be near Northern Eridanus. [23] Cameras for Allsky Meteor Surveillance (CAMS) did not detect any activity in the presumed area of the sky during 2013 and 2014. [23] The object has a low albedo of 0.06, which is only slightly more than a typical comet that has an albedo of 0.03-0.05. [5]
3200 Phaethon, provisionally designated 1983 TB, is an active Apollo asteroid with an orbit that brings it closer to the Sun than any other named asteroid. For this reason, it was named after the Greek myth of Phaëthon, son of the sun god Helios. It is 5.8 km (3.6 mi) in diameter and is the parent body of the Geminids meteor shower of mid-December. With an observation arc of 35+ years, it has a very well determined orbit. The 2017 Earth approach distance of about 10 million km was known with an accuracy of ±700 m.
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.
2007 TU24 is an Apollo near-Earth asteroid that was discovered by the Catalina Sky Survey in Arizona on 11 October 2007. Imaging radar has estimated that it is 250 meters (820 ft) in diameter. The asteroid passed 554,209 kilometer (344,370 mile or 1.4-lunar distance) from Earth on 29 January 2008 at 08:33 UTC. (At the time of the passage it was believed the closest for any known potentially hazardous asteroid (PHA) of this size before 2027, but in 2010 2005 YU55 was measured to be 400 meters in diameter.) At closest approach 2007 TU24 had an apparent magnitude of 10.3 and was about 50 times fainter than the naked eye can see. It required about a 3-inch (76 mm) telescope to be seen.
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.
(450894) 2008 BT18 is a sub-kilometer asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 31 January 2008, by the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. The eccentric asteroid measures approximately 600 meters in diameter and has a composition of a basaltic achondrite.
(308635) 2005 YU55, provisionally named 2005 YU55, is a potentially hazardous asteroid 360±40 meters in diameter, as measured after its Earth flyby. Previously it was estimated to be 310 meters or about 400 m (1,300 feet) in diameter. It was discovered on 28 December 2005 by Robert S. McMillan at Steward Observatory, Kitt Peak. On 8 November 2011 it passed 0.85 lunar distances (324,900 kilometers; 201,900 miles) from Earth.
2012 BX34 is a small Aten asteroid that made one of the closest recorded asteroid close approaches of Earth on 27 January 2012. It passed within 0.0004371 AU (65,390 km; 40,630 mi) of Earth during its closest approach at 15:25 GMT. 2012 BX34 measures around 8 meters (26 ft) across; if it had impacted in 2012, it would have been too small to pass through Earth's atmosphere intact.
367943 Duende (provisional designation 2012 DA14) is a micro-asteroid and a near-Earth object of the Aten and Atira group, approximately 30 meters (98 ft) in diameter. It was discovered by astronomers of the Astronomical Observatory of Mallorca at its robotic La Sagra Observatory in 2012, and named for the duende, a goblin-like creature from Iberian and Filipino mythology and folklore. Duende is likely an uncommon L-type asteroid and significantly elongated. For an asteroid of its size, it has a relatively long rotation period of 9.485 hours.
(285263) 1998 QE2, provisional designation 1998 QE2, is a dark asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Amor group, approximately 3 kilometers in diameter. It was discovered on 19 August 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. Its sub-kilometer minor-planet moon was discovered by radar on 30 May 2013.
(192642) 1999 RD32, provisional designation: 1999 RD32, is an asteroid and suspected contact binary on an eccentric orbit, classified as a large near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 5 kilometers (3 miles) in diameter. It was discovered on 8 September 1999, at a magnitude of 18, by astronomers of the LINEAR program using its 1-meter telescope at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. The asteroid is likely of carbonaceous composition and has a rotation period of 17.08 hours.
2014 HQ124 is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Aten group, approximately 400 meters (1,300 feet) in diameter. It passed 3.25 lunar distances (LD) from Earth on 8 June 2014. It was discovered on 23 April 2014 by NEOWISE. It is estimated that an impact event would have had the energy equivalent of 2,000 megatons of TNT and would have created a 5 km (3 mi) impact crater. The news media misleadingly nicknamed it The Beast. 2014 HQ124 previously passed this close to Earth in 1952 and will not again until at least 2307. Radar imaging suggests it may be a contact binary.
(357439) 2004 BL86 is a bright sub-kilometer asteroid and binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters (980 ft) in diameter. It was discovered on 30 January 2004 by astronomers of the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. Its 70-meter (200 ft) moon was discovered during the asteroid's close approach to the Earth in January 2015.
2014 SC324 is a sub-kilometer asteroid and fast rotator, classified as a near-Earth object of the Apollo group, approximately 50 meters in diameter. It was first observed on 30 September 2014, by the Mount Lemmon Survey at an apparent magnitude of 21 using a 1.5-meter (59 in) reflecting telescope. With an absolute magnitude of 24.3, the asteroid is about 37–85 meters in diameter.
2012 TC4 is a tumbling micro-asteroid classified as a bright near-Earth object of the Apollo group, approximately 10 meters (30 feet) in diameter. It was first observed by Pan-STARRS at Haleakala Observatory on the Hawaiian island of Maui, in the United States. As of 1 October 2017, it had a small Earth minimum orbital intersection distance of 0.000149 AU (22,300 km). On 12 October 2017, it passed Earth at 0.00033524 AU (50,151 km). The asteroid was removed from the Sentry Risk Table on 16 October 2017 and with a 5-year observation arc has a well-known orbit. For example, on the previously risk-listed date of 12 October 2022, it is now known that the asteroid will be more than 3 AU (450 million km) from Earth.
(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.
(671294) 2014 JO25 is a near-Earth asteroid. It was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona - a project of NASA's NEO (Near Earth Object) Observations Program in collaboration with the University of Arizona.
(163899) 2003 SD220 is a sub-kilometer asteroid and tumbling slow rotator, classified as near-Earth object and potentially hazardous asteroid of the Aten group, which orbit the Sun between Venus and Earth. Its orbital period of 0.75 years means that it orbits the Sun about 4 times for every 3 of the Earth. It was discovered on 29 September 2003, by astronomers of the Lowell Observatory Near-Earth-Object Search at Anderson Mesa Station near Flagstaff, Arizona.
(505657) 2014 SR339, provisional designation 2014 SR339, is a dark and elongated asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 970 meters (3,200 feet) in diameter. It was discovered on 30 September 2014, by NASA's Wide-field Infrared Survey Explorer telescope (WISE) in Earth's orbit. Closely observed at Goldstone and Arecibo in February 2018, it has a rotation period of 8.7 hours.
2017 VR12 is a sub-kilometer asteroid with a somewhat elongated and angular shape, approximately 160 meters (500 feet) in diameter. It is classified as near-Earth object and potentially hazardous asteroid of the Apollo or Amor group. The V-type asteroid has a rotation period of approximately 1.5 hours. It was first observed on 10 November 2017 by the 60-inch Pan-STARRS 1 telescope at Haleakala Observatory in Hawaii.
2017 YE5 is a binary pair of asteroids of approximately equal size and mass, each about 0.9 km (0.56 mi) in diameter. Classified as a near-Earth asteroid and potentially hazardous object of the Apollo group, 2017 YE5 was discovered by amateur astronomer Claudine Rinner at the Oukaïmeden Observatory on 21 December 2017. On 21 June 2018, the pair of asteroids passed within 15.5 lunar distances or approximately 6 million km (3.7 million mi) from Earth. During the close encounter, 2017 YE5 was resolved in high detail by concurrent radar observations by the Arecibo and Green Bank observatories, along with individual observations by the Goldstone Solar System Radar. 2017 YE5 is likely an extinct or dormant comet due to its distant elliptical orbit and dark red surface.