* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Solar System -> Toutates
Post Info TOPIC: Toutates
Blobrana


L

Posts: 131433
Date:
Asteroid (4179) Toutatis
Permalink  
 

Asteroid (4179) Toutatis makes its closest approach to the Earth (2.818 AU) on the 9th April 2018.



__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Title: Orientation and Rotational Parameters of Asteroid 4179 Toutatis: New Insights from Chang'e-2's Close Flyby
Author: Yuhui Zhao, Jianghui Ji, Jiangchuan Huang, Shoucun Hu, Xiyun Hou, Yuan Li, Wing-Huen Ip

In this work, we investigate the rotational dynamics of the ginger-shaped near-Earth asteroid 4179 Toutatis, which was closely observed by Chang'e-2 at a distance of 770±120 meters from the asteroid's surface during the outbound flyby Huang2013 on 13 December 2012. A sequence of high-resolution images was acquired during the flyby mission. In combination with ground-based radar observations collected over the last two decades, we analyze these flyby images and determine the orientation of the asteroid at the flyby epoch. The 3-1-3 Euler angles of the conversion matrix from the J2000 ecliptic coordinate system to the body-fixed frame are evaluated to be -20.1°±1°, 27.6°±1° and 42.2°±1°, respectively. The least-squares method is utilized to determine the rotational parameters and spin state of Toutatis. The characteristics of the spin-state parameters and angular momentum variations are extensively studied using numerical simulations, which confirm those reported by Takahashi2013. The large amplitude of Toutatis' precession is assumed to be responsible for its tumbling attitude as observed from Earth. Toutatis' angular momentum orientation is determined to be described by lambdaH=180.2+0.2°-0.3° and BetaH=-54.75+0.15°-0.10°, implying that it has remained nearly unchanged for two decades. Furthermore, using Fourier analysis to explore the change in the orientation of Toutatis' axes, we reveal that the two rotational periods are 5.38 and 7.40 days, respectively, consistent with the results of the former investigation. Hence, our investigation provides a clear understanding of the state of the rotational dynamics of Toutatis.

Read more (1170kb, PDF)



__________________
Blobrana


L

Posts: 131433
Date:
Asteroid Toutatis
Permalink  
 

Asteroid (4179) Toutatis makes its closest approach to the Earth (2.852 AU) on the 10th April 2014



__________________
Blobrana


L

Posts: 131433
Date:
Asteroid (4179) Toutatis
Permalink  
 

Title: Orbital Evolution of 4179 Toutatis
Authors: Suryadi Siregar, Endang Soegiartini

Asteroid 1934 CT;1989 AC, well known as 4179 Toutatis, is an Apollo and Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with Jupiter and a 1:4 resonance with the Earth, and frequent close approaches to the Earth. It is listed as a potential hazardous object (PHA). The aim of this study is to investigate the possibility of 4179 Toutatis to be ejected from the Solar System. This paper presents an orbital evolution of 4179 Toutatis in time interval of ~300 kyr. Investigation of its orbital evolution is conducted by using the Mercury subroutine package, where the gravitational perturbations of eight major planets in the Solar System are considered. Over very short time scales (~300 kyr) relative to the Solar System life time (~10 Gyr), the asteroid 4179 Toutatis gave an example of chaotic motion that can cause asteroid to move outward and may be followed by escaping from the Solar System.

Read more (381kb, PDF)



__________________
Blobrana


L

Posts: 131433
Date:
RE: Toutates
Permalink  
 

Ephemeris

Date       UT      R.A. (J2000) Decl.    Delta     r     El.    Ph.   Mag
2012 12 16 000000 03 14 03.6 +12 01 59   0.053   1.028  144.7  33.6  10.5
2012 12 17 000000 03 38 03.3 +14 01 15   0.057   1.034  149.9  28.6  10.5
2012 12 18 000000 03 59 17.1 +15 37 56   0.061   1.039  154.2  24.3  10.5
2012 12 19 000000 04 17 53.8 +16 55 22   0.066   1.045  157.9  20.8  10.6
2012 12 20 000000 04 34 08.4 +17 57 04   0.071   1.051  160.8  17.9  10.7
2012 12 21 000000 04 48 18.1 +18 46 17   0.077   1.057  163.3  15.5  10.8
2012 12 22 000000 05 00 39.9 +19 25 42   0.082   1.064  165.3  13.6  10.9
2012 12 23 000000 05 11 29.3 +19 57 27   0.089   1.070  166.9  12.1  11.0
2012 12 24 000000 05 21 00.1 +20 23 13   0.095   1.077  168.1  10.8  11.1
2012 12 25 000000 05 29 23.9 +20 44 17   0.101   1.083  169.1   9.9  11.2
2012 12 26 000000 05 36 50.5 +21 01 40   0.108   1.090  169.9   9.1  11.3
2012 12 27 000000 05 43 28.2 +21 16 07   0.115   1.097  170.5   8.6  11.4
2012 12 28 000000 05 49 24.1 +21 28 14   0.122   1.104  170.9   8.1  11.5
2012 12 29 000000 05 54 43.8 +21 38 27   0.129   1.111  171.1   7.9  11.7
2012 12 30 000000 05 59 32.4 +21 47 08   0.136   1.118  171.2   7.7  11.8
2012 12 31 000000 06 03 53.8 +21 54 34   0.143   1.125  171.2   7.7  11.9


__________________
Blobrana


L

Posts: 131433
Date:
Asteroid 4179 Toutatis (1989 AC)
Permalink  
 

Local Astronomer Gets Video of Near-Miss Asteroid

Dan Marcus, observatory director of the Buffalo Astronomical Association, was manning the telescopes at the Beaver Meadow Audubon Centre in North Java Tuesday night to capture the images
Read more



__________________
Blobrana


L

Posts: 131433
Date:
RE: Toutates
Permalink  
 

"Chang'e II" detection of asteroids

Read more  



__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Surface Features of Asteroid Toutatis Revealed by Radar

Spoiler

This video, generated from Goldstone's Solar System Radar, shows the rotation of the asteroid when it was 4.3 million miles from Earth.



__________________
Blobrana


L

Posts: 131433
Date:
Asteroid 4179 Toutatis (1989 AC)
Permalink  
 

The 5400 metre wide asteroid 4179 Toutatis will make a close pass (18.0 lunar distances, 0.0463 AU), travelling at 11.91 km/second, to the Earth-Moon system on the 12th December, 2012 @ 06:40 UT ±00:01. 

See more 

The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).



__________________
Blobrana


L

Posts: 131433
Date:
RE: Toutates
Permalink  
 

Title: Composition of Near-Earth Asteroid (4179) Toutatis
Authors: Vishnu Reddy, Juan Andreas Sanchez, Michael Gaffey, Paul Abell, Lucille Le Corre, Paul Hardersen

Surface composition of near-Earth asteroid (4179) Toutatis is consistent with an undifferentiated L-chondrite composition. This is inconsistent with early observations that suggested high pyroxene iron content and a differentiated body.

Read more (325kb, PDF)



__________________
1 2  >  Last»  | Page of 2  sorted by
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Solar System -> Toutates


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard