Jump to content

2020 VT4

From Wikipedia, the free encyclopedia

2020 VT4
Discovery [1][2]
Discovered byATLAS-MLO
Discovery siteMauna Loa Obs.
Discovery date14 November 2020
Designations
2020 VT4
A10sHcN [3][4]
NEO·Apollo(pre-flyby)[5]
Aten(post-flyby)[2]
Orbital characteristics [2]
Epoch17 December 2020 (JD2459200.5)
(post-flyby as pre-flyby was very different)
Uncertainty parameter5
Observation arc5 days
Aphelion1.092AU
Perihelion0.724 AU
0.908 AU
Eccentricity0.20299
0.86 yr (315.92 d)
143.860°
1° 8m22.286s/ day
Inclination10.173°
231.422°
14 November 2020 12:17 UT (pre-flyby)[5]
53.678°
EarthMOID0.0002 AU
Physical characteristics
5–11m(assumed)[6]
20.0 (current)[7]
17.3 (at discovery)[1]
28.66±0.50[5]
28.7[2]

2020 VT4is a tinynear-Earth asteroidthat passed 370 km (230 mi) above Earth's surface on 13 November 2020 at 17:20UTC.[a]The asteroid was discovered by theAsteroid Terrestrial-impact Last Alert System(ATLAS) survey at theMauna Loa Observatoryfifteen hours after its closest approach to Earth.[b]The Earth encounterperturbedthe asteroid's trajectory from an Earth-crossingApollo-type orbit to anAten-type orbit, subsequently reducing the asteroid's heliocentricorbital periodfrom 1.5 years to 0.86 years.[5][2]

2020 VT4passed closer to Earth than any known asteroid, except for those that becamemeteors.It passed closer than2020 QGand2011 CQ1,which passed about 3,000 km and 5,500 km from Earth's surface, respectively.[6]Given an estimatedabsolute magnitudeof 28.7,2020 VT4is estimated to be around 5 to 10 metres in diameter. Had itimpactedEarth, it would mostly have disintegrated duringatmospheric entryand might have left a commonstrewn field.[4]

Discovery

[edit]

2020 VT4was discovered on 14 November 2020, by theAsteroid Terrestrial-impact Last Alert System(ATLAS) survey at theMauna Loa ObservatoryinHawaii.The asteroid was discovered fifteen hours after its closest approach to Earth, moving about 0.28degreesper hour across theconstellationFornaxat anapparent magnitudeof 17.3.[1][c]At the time of discovery,2020 VT4was about 0.003astronomical units(450,000 km; 280,000 mi) from Earth and had asolar elongationof 134 degrees.[8]

The discovery was subsequently reported to theMinor Planet Center'sNear-Earth Object Confirmation Page(NEOCP) under the internal designation A10sHcN.[3][4]Further refinements to the asteroid's preliminary trajectory were made with additional follow-up observations by theGalhassin Robotic Telescope,iTelescope Observatory,and theGlenlee Observatory.The asteroid was also identified in earlier observations by theZwicky Transient Facilityone hour before its discovery by ATLAS-MLO. The asteroid was then confirmed by the Minor Planet Center and announced with theprovisional designation2020 VT4on 14 November 2020.[1]

Orbit and classification

[edit]

2020 VT4is currently on anEarth-crossingAten-typeorbit with an orbitalsemi-major axisof 0.908 AU (136 million km; 84.4 million mi) and anorbital periodof 0.86 years or 316 days.[2]With a nominalperiheliondistance of0.724 AUand anapheliondistance of1.092 AU,2020 VT4's orbit extends fromVenusto Earth, resulting in occasional close passes with these planets. The nominalminimum orbit intersection distances(MOID) with Venus and Earth are approximately 0.0351 AU (5,250,000 km; 3,260,000 mi) and 0.0002 AU (30,000 km; 19,000 mi), respectively.[4]2020 VT4has anorbital eccentricityof 0.203 and aninclinationof 10.2 degrees to theecliptic.[2]

Before the Earth encounter on 13 November 2020,2020 VT4had anApollo-typeorbit crossing the paths of Earth andMars.It had a perihelion distance of0.989 AUand a semi-major axis of 1.31 AU (196 million km; 122 million mi), with an orbital period of 1.5 years or 550 days. The orbit had an orbital eccentricity of 0.246 and an inclination of 12.9 degrees to the ecliptic. TheJet Propulsion Laboratory'sSmall-Body Databasestill provides an Apollo-typeosculating orbitfor2020 VT4based on theepoch31 May 2020 (JD2459000.5) before the Earth encounter; excluding all gravitationalperturbations,the given orbit implies the asteroid would have passed perihelion 19 hours after it passed Earth.[5]

Orbital Elements
Parameter Epoch Period
(p) 		Aphelion
(Q) 		Perihelion
(q) 		Semi-major axis
(a) 		Eccentricity
(e) 		Inclination
(i)
Units (days) AU (°)
Pre-flyby 2020-May-31[5] 549.2 1.636 0.989 1.313 0.2462 12.909°
Post-flyby 2020-Dec-17[2][9] 315.9 1.092 0.724 0.908 0.2028 10.161°

2020 flyby

[edit]

On 13 November 2020, 15 hours prior to its discovery,2020 VT4passed 373 ± 25 km (232 ± 16 mi) over theSouth Pacific Oceanat 17:20 UTC.[5][10]At this time of closest approach,2020 VT4's on-sky position was close to the Sun with a minimum solar elongation of 36 degrees, making it unobservable to Earth-based telescopes.[11][12]2020 VT4passed closer to Earth than any known asteroid, except for those that becamemeteors.It passed closer than2020 QGand2011 CQ1,which passed about 3,000 km and 5,500 km from Earth's surface, respectively.[6]

Animation of 2020 VT4's orbit - 2020 flyby
Around the Sun
Around the Earth
Sun·2020 VT4·Earth
Closest non-impacting asteroids to Earth, exceptEarth-grazing fireballs
(usingJPL SBDBnumbers and Earth radius of 6,378 km)
Asteroid Date Distance from
surface of Earth 		Uncertainty in
approach distance 		Observation arc Reference
2020 VT4 2020-11-13 17:21 368 km ±11 km 5 days (34 obs) data
2020 QG 2020-08-16 04:09 2939 km ±11 km 2 days (35 obs) data
2021 UA1 2021-10-25 03:07 3049 km ±10 km 1 day (22 obs) data
2023 BU 2023-01-27 00:29 3589 km ±<1 km 10 days (231 obs) data
2011 CQ1 2011-02-04 19:39 5474 km ±5 km 1 day (35 obs) data
2019 UN13 2019-10-31 14:45 6235 km ±189 km 1 day (16 obs) data
2008 TS26 2008-10-09 03:30 6260 km ±970 km 1 day (19 obs) data
2004 FU162 2004-03-31 15:35 6535 km ±13000 km 1 day (4 obs) data

See also

[edit]

Notes

[edit]
  1. ^2020 VT4's nominal closest approach distance from Earth's center is approximately 4.509×10−5AU(0.01755LD), or 6,745 km (4,191 mi). The asteroid'saltitudefrom Earth's surface is the difference between the geocentric approach distance andEarth's radius:6,745 – 6,371 = 374 km.
  2. ^2020 VT4did not have asolar elongationgreater than 90 degrees until about 10 minutes after closest approach.
  3. ^Thecelestial coordinatesof2020 VT4at the time of discovery were02h45m59.46s−27° 18′ 36.9″.[1]SeeFornaxfor constellation coordinates.

References

[edit]
  1. ^abcde"MPEC 2020-V152: 2020 VT4".Minor Planet Electronic Circular.Minor Planet Center.14 November 2020.Archivedfrom the original on 14 November 2020.Retrieved14 November2020.
  2. ^abcdefgh"2020 VT4".Minor Planet Center.International Astronomical Union.Archivedfrom the original on 3 December 2020.Retrieved14 November2020.
  3. ^ab"2020 VT4".NEO Exchange.Las Cumbres Observatory.14 November 2020.Archivedfrom the original on 14 November 2020.Retrieved14 November2020.
  4. ^abcd""Pseudo-MPEC" for A10sHcN = 2020 VT4".Project Pluto. 14 November 2020.Archivedfrom the original on 14 November 2020.Retrieved14 November2020.
  5. ^abcdefg"JPL Small-Body Database Browser: 2020 VT4"(2020-11-19 last obs.).Jet Propulsion Laboratory.Archivedfrom the original on 15 November 2020.Retrieved17 November2020.
  6. ^abc"NEO Earth Close Approaches".Center for Near Earth Object Studies.Jet Propulsion Laboratory.Archivedfrom the original on 19 October 2017.Retrieved14 November2020.
  7. ^"2020VT4".Near Earth Objects – Dynamic Site.Department of Mathematics, University of Pisa, Italy.Archivedfrom the original on 22 November 2020.Retrieved14 November2020.
  8. ^"2020VT4 Ephemerides".Near Earth Objects – Dynamic Site(Ephemerides at discovery (obs. code T08)). Department of Mathematics, University of Pisa, Italy.Archivedfrom the original on 27 November 2020.Retrieved18 November2020.
  9. ^"Orbital Elements for Asteroid (2020 VT4)".Horizonsoutput.Jet Propulsion Laboratory.Retrieved14 November2020.( "Ephemeris Type" select "Orbital Elements"·Set "Time Span" to 2020-Dec-17)
  10. ^Irizarry, Eddie (16 November 2020)."This asteroid just skimmed Earth's atmosphere".EarthSky.Archivedfrom the original on 16 November 2020.Retrieved18 November2020.
  11. ^"2020VT4 Ephemerides".Near Earth Objects – Dynamic Site(Ephemerides at closest approach (geocentric)). Department of Mathematics, University of Pisa, Italy.Archivedfrom the original on 3 December 2020.Retrieved18 November2020.
  12. ^Dickinson, David (17 November 2020)."A Record Close Shave: Asteroid 2020 VT4 Just Skimmed by Earth".Universe Today.Archivedfrom the original on 17 November 2020.Retrieved18 November2020.
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=2020_VT4&oldid=1204729588"