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EUROPEAN EDUCATIONAL
ASTRONOMICAL PROGRAMME "CATCH A STAR" 2004 |
Toutatis – one of the nearest and most dangerous asteroids

Summary: We
chose for our project a very interesting asteroid called Toutatis. We found
a lot of interesting information about it and its movement. We made our own
observations of this dangerous for the Earth object. The animation of the fast-moving
asteroid that we made using our observations received from the Schmidt telescope
in NAO-Rozhen is of great interest for us. We prepared and conducted an amusing
exercise about asteroids with 12-year-old students who study astronomy. Together
with them we made a small 3D model of Toutatis from plasticine and used photographs
and animations from Internet for its creation. Guided by our desire to expand
students’ knowledge we made a paper model of the asteroid Eros. Then,
we compared the two asteroids. Thus students received a real notion for various
asteroids and their ways of movement.
Contents: 1. Introduction 2. Discovery 3. Scientists explore Toutatis - Rotation of the asteroid - Nature of the asteroid 4. Orbital elements 5. The last passage of the asteroid 6. Our observations of Toutatis 7. Exercise”Let’s make an asteroid” 8. Conclusion 9. Bibliography |
![]() Fig.1 Team: Trayan Petkov – 16 years old Leader: Veselka Radeva Astronomical Observatory, Varna, Bulgaria |
Fig.2. The high-resolution image of Toutatis |
From High Resolution Goldstone
Images
These are 8 of the "high resolution" Goldstone images that are being used to produce a higher-resolution 3D model of Toutatis. (From Ostro et al., Science 270:80-83, 1995--© Copyright 1995 by the AAAS) [2] High Resolution Image |
Shaded Relief Map of Asteroid 4179 Toutatis
This is a shaded relief map of asteroid 4179 Toutatis. As with all maps, it is the cartographer's interpretation and not all features are necessarily certain given the limited data available. This interpretation stretches the data as far as is feasible. (Courtesy Phil Stooke, NSSDC, and NASA) |
Scientists have made a computer model of the Earth-orbit-crossing
asteroid Toutatis. These views of the asteroid show shallow craters, linear
ridges, and a deep topographic "neck" whose geologic origin
is not known. It may have been sculpted by impacts into a single, coherent
body, or Toutatis might actually consist of two separate objects that
came together in a gentle collision. (Courtesy Scott Hudson, Washington
State University)[2] |
![]() Fig.3. Computer Model of Toutatis Scott Hudson, Washington State University |
![]() Fig.4. The rotation of the asteroid Copyright 1995 by the AAAS |
We were most interested in the rotation
of the asteroid. This image shows the shape and non-principal-axis spin
state of asteroid 4179 Toutatis rendered at a particular instant. The
red, green, and blue axes are the principal axes of inertia; the magenta
axis is the angular momentum vector; the yellow axis is the spin vector.
If a flashlamp was attached to the short axis of inertia (the red axis)
and flashed it every 15 minutes for a month, it would trace out the intricate
path indicated by the small spheres stacked end-to-end. If this process
was continued forever the path would never repeat. Toutatis's spin state
differs radically from those of the vast majority of solar system bodies
that have been studied. (© Copyright 1995 by the AAAS) |
For us it was very interesting to understand how
the asteroid turns on Nine Successive Days. This image
shows the non-principal-axis spin state of asteroid 4179 Toutatis at one-day
intervals (from left to right, top to bottom). The red, green, and blue
axes are the principal axes of inertia; the magenta axis is the angular
momentum vector; the yellow axis is the spin vector. Toutatis does not
spin about a single axis. Instead, its spin vector traces a curve around
the asteroid's surface once every 5.41 days. During this time the object
rotates once about its long axis, and every 7.35 days, on average, the
long axis precesses about the angular momentum vector. The combination
of these two motions with different periods give Toutatis its bizarre
"tumbling" rotation. (Courtesy Scott Hudson, Washington State
University)[2] |
![]() Fig.5. Axes of rotation Copyright 1995 by the AAAS |
In December 1992, Toutatis made a close approach to Earth. At the time, it was an average of about 4 million kilometers (2.5 million miles) from Earth. Images of Toutatis were acquired using radar carried out at the Goldstone Deep Space Communications Complex in California's Mojave desert. For most of the work, a 400,000-watt coded radio transmission was beamed at Toutatis from the Goldstone main 70-meter (230-foot) antenna. The echoes, which took as little as 24 seconds to travel to Toutatis and back, were received by the new 34-meter (112-foot) antenna and relayed back to the 70-meter (230-foot) station, where they were decoded and processed into images. [3] The most important facts drawn from the observations of scientists: The images of Toutatis reveal two irregularly shaped, cratered objects
about 4 and 2.5 kilometers (2.5 and 1.6 miles) in average diameter which
are probably in contact with each other. These "contact binaries"
may be fairly common since another one, 4769 Castalia, was observed
in 1989 when it passed near the Earth. Numerous surface features on
Toutatis, including a pair of half-mile-wide craters, side by side,
and a series of three prominent ridges -- a type of asteroid mountain
range -- are presumed to result from a complex history of impacts. |
Toutatis close approaches |
|
Date |
Distance in AU |
1996 Nov. 29.96 |
0.0354 |
2000 Oct. 31.19 |
0.0739 |
2004 Sept.29.5 |
0.0104 |
2008 Nov. 9.50 |
0.0503 |
Objects | Distance to the Sun | Closest distance to the Earth | e | Size | Number of the axes of turning |
4179 Toutatis | 1.15AE | 1 549 719 km | 0.6336092 | 4.6 x 2.4 km | 5 |
433 Eros | 1.13AE | 54 900 000 km | 0.2228069 | 33x13x13 km | 1 |
Animation of Toutatis - http://www.solarviews.com/cap/ast/toutspin.htm 6. Our observations
of the asteroid |
![]() Fig.6 The asteroid Toutatis |
![]() Fig.7 The asteroid Toutatis |
![]() Fig.8 The asteroid Toutatis |
The images were made on 08/11/2004 with Schmidt telescope,
exp.180s, We made an animation that shows the path of the asteroid
Toutatis among the stars. We convinced ourselves that the asteroid moves
very fast because it is very close the Sun. |
For us it was extremely interesting
to make an exercise with our friends from the astronomical courses in
the Observatory in Varna.
![]() Fig.9. The class photo by Nadezhda Radeva |
![]() Fig.10. Explanation of the rotation of the asteroids photo by Nadezhda Radeva |
Teacher lesson plan |
Objective: Most asteroids
are not spherical like planets. Students will mode the 3D from of asteroids
Toutatis and a paper model of asteroid Eros. Necessary materials: plasticine, wooden sticks, scissors, glue, a sheet of paper with the shape of the asteroid Eros that will be made during the lesson. Estimated Time: Depending on the ability level of your students this could take from 20 to 40 minutes. |
![]() Fig.11 The model of Toutatis photo by Nadezhda Radeva |
![]() Fig.12 The model of Toutatis photo by Nadezhda Radeva |
Procedure: Step1: The teacher has to present to students short information about the discovery of the asteroid and to show the movement of the asteroid around the Sun. The students discuss the moments of the passage of the asteroid through perihelion, the speed of the asteroid in perihelion and aphelion and the slope of the asteroid’s orbit. Step 2: Students look at photos of the asteroid that have been obtained by different observatories in the Internet. They make a 3D model of the asteroid from plasticine. By using the maps of the surface of the asteroid they make the craters and the swellings on it. They discuss the real size of the asteroid that has been obtained by radio observations. They watch animations of Toutatis and show the movement of the asteroid around its 5 axes. The 5 axes are made from the wooden sticks that have to be put in the plasticine. Step 3: Students look at photos and animations of the asteroid Eros. They discuss its size, parameters of its orbit and its rotation. Then, they put together the asteroid Eros from paper and compare the two objects’ orbital elements, size and rotation around their axes. |
![]() Fig.13.The paper model of the asteroid Eros photo by Nadezhda Radeva |
![]() Fig.14.The paper models of the asteroid Eros photo by Nadezhda Radeva |
We would like to thank Nadezhda Lyubomirova Radeva
(student from the astronomical courses in the Astronomical Observatory,
Varna) for the creation of the web-page of our project! For contacts: |