2012 TC 4

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Asteroid
2012 TC 4
Composite image from 2012 TC4 (2017)
Composite image from 2012 TC4 (2017)
Properties of the orbit ( animation )
Epoch:  February 16, 2017 ( JD 2,457,800.5)
Orbit type Near-Earth asteroid, Apollo-type
Major semi-axis 1.406  AU
eccentricity 0.336
Perihelion - aphelion 0.934 AU - 1.878 AU
Inclination of the orbit plane 0.9 °
Length of the ascending node 198.3 °
Argument of the periapsis 222.6 °
Time of passage of the perihelion 16th November 2017
Sidereal period 1.67 years
Mean orbital velocity 24.4 km / s
Physical Properties
Medium diameter 10-30 m
12-27 m
Rotation period 12 min 14 sec
Absolute brightness 26.7 mag
history
Explorer Pan-STARRS
Date of discovery 4th October 2012
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

2012 TC 4 is a near-Earth asteroid of the Apollo type , which was discovered on October 4, 2012 by the large telescope system Pan-STARRS .

2012 TC 4 moves at a distance of 0.934 ( perihelion ) to 1.878 ( aphelion ) astronomical units in 607 days around the sun. The orbit is inclined only 0.9 ° to the ecliptic , its eccentricity is relatively large at 0.34.

The original, based on still few observations classified as potentially hazardous asteroid ( english potentially hazardous asteroid , PHA ) was lifted in the course of further observations.

Little is known about the asteroid itself other than the properties of its orbit and rotation. However, it can be assumed that it is a monolith and not a rubble pile .

List of approximations

List of approaches to earth

Time (UT) Uncertainty time Distance (km) Uncertainty (km) Relative speed (km / s)
March 11, 1987 6:40 PM ± 53 hours 48808468.000 1054757.000 4.7383
October 13, 1996 2:03 am ± 4 min 753163.000 7069.000 6.4448
March 3, 1997 6:05 am ± 18 min 46927831.000 5385.000 4.1904
August 2, 2009 9:30 am ± 2 min 68968901.000 516.000 7.0395
February 12, 2010 2:34 am ± <1 min 40182970.000 1253.000 14.6402
October 12, 2012 5:30 am ± <1 min 94965.000 0.324 7.1227
October 12, 2017 5:42 am ± <1 min 50151.793 0.394 7.6470
August 28, 2019 3:58 PM ± 5 min 68910500.000 816.000 2.8074
December 29, 2019 9:42 am ± <1 min 34467321.000 1063.000 13.8174
September 5, 2048 3:34 PM ± 2 min 51740568.000 14557.000 17.2265

Status: October 25, 2017 ( status prior to 2017 )

List of approaches to the moon

Time (UT) Uncertainty time Distance (km) Uncertainty (km) Relative speed (km / s)
October 11, 1986 10:25 ± <10 hours 1324129 1438085.000 7.6929
October 13, 1996 5:39 PM ± <4 min 529709 6371.000 7.1435
October 12, 2012 9:45 PM ± <1 min 113886 0.670 6.7732
October 12, 2017 7:19 PM ± <1 min 277697 0.992 6.1012
October 19, 2050 1:31 AM ± <13 min 1402487 7919.000 7,1462

Status: October 25, 2017 ( status prior to 2017 )

(Bold line marks discovery time.)

Flyby 2017

When a forecast was published in August 2017 that the asteroid would fly relatively close to Earth, it received a certain amount of media attention.

Animation of a forecast

The following calculated animation from September 11, 2017 shows how 2012 TC4 (green) is deflected by the earth (day side: blue) as it flies past it. To illustrate the distances, a geosynchronous satellite (pink) and the moon (gray) are also drawn in this animation. The green line of the orbit of the asteroid becomes darker in the area in which it dips below (= south) the ecliptic. 2012 TC4 animation.gif

Last forecasts before the flyby

A forecast made by NASA's Goldstone team on October 11, 2017 said: The Earth's flyby on October 12, 2017 could result in a change in the rotation of the asteroid. There is also a small probability that the surface or even the shape of the asteroid will change if it is a loose rock pile ("rubble pile"). During the flyby , the earth's gravity will bend the orbit of 2012-TC4, resulting in a new orbit: the major semi-axis will increase and the eccentricity will decrease. The inclination and the orbital time increase. Since the exact extent and the exact direction of the deflection could only be predicted with limited accuracy on October 11, 2017 - the time of the last calculation by JPL to date - due to the uncertainty of the orbit forecast, the orbit measurement after the October passage will be higher Probability also yield significantly different values ​​for the future approximations.

Flyby on October 12, 2017

On October 12, 2017, the asteroid flew past Earth as predicted at around 6:00 a.m. UT , its speed being 7.647 km / s and its distance to the center of the earth (50,151.793 ± 0.394) km . Its distance to the earth's surface was thus a little more than 44,000 km or about 3.5 earth's diameter .

Remarks

  1. ↑ The distances are measured from the asteroid to the center of the earth.
  2. ↑ The distances are measured from the asteroid to the center of the moon.

swell

  1. ↑ Asteroid 2012 TC4 to Safely Pass Earth This October. In: cneos.jpl.nasa.gov. July 12, 2017. Retrieved August 20, 2017.
  2. ↑ Teletext of ZDF of October 12, 2017, p. 141: “Asteroid 2012 TC4 flies just past the earth”.
  3. ↑ Tomasz Nowakowski: Will Asteroid 2012 TC4 Hit Earth in October 2017. In: spacedaily.com. April 17, 2015, accessed October 12, 2017.
  4. ↑ MPEC 2012-T18: 2012 TC4. In: minorplanetcenter.net. April 17, 2015, accessed August 20, 2017.
  5. ↑ a b c JPL Small-Body Database Browser. Retrieved October 29, 2017.
  6. ↑ 20-meter-chunk races close to earth. In: Spiegel online . August 18, 2017. Retrieved August 20, 2017 .
  7. ↑ Goldstone Radar Observations Planning: 2012 TC4.
  8. ↑ Asteroid 2012 TC4 races just past the earth. In: focus.de. October 12, 2017.