The story of asteroid 2008 TC3 - PowerPoint PPT Presentation

Loading...

PPT – The story of asteroid 2008 TC3 PowerPoint presentation | free to download - id: 81d4a-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

The story of asteroid 2008 TC3

Description:

2008 October 6, 6:39 UT. Discovery of a small asteroid, soon called 2008 TC3 ... 2008 October 6, about 18h UT. Unusual: Meteor community (a.o. Dr. Jenniskens) ... – PowerPoint PPT presentation

Number of Views:47
Avg rating:3.0/5.0
Slides: 44
Provided by: toberman
Learn more at: http://archive.seti.org
Category:
Tags: asteroid | story | tc3 | ut

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: The story of asteroid 2008 TC3


1
  • The story of asteroid 2008 TC3


Peter Jenniskens (SETI Institute)
07/14/09
2
Meteorites are great, but from which asteroid do
they come?
3
Earth is in a shooting gallery,lots of asteroids
passing close...
http//www.cfa.harvard.edu/iau/Animations/EarthRid
e2008.gif
4
2008 October 6, 639 UT Discovery of a small
asteroid, soon called 2008 TC3
Discovery Image
Catalina Sky Survey (Richard Kowalski)
5
2008 October 6, 1459 UT Minor Planet Center
Its coming right at us!
MPEC 2008-T50 The nominal orbit given above has
2008 TC3 coming to within one earth radius around
Oct. 7.1. The absolute magnitude indicates that
the object will not survive passage through the
atmosphere. Steve Chesley (JPL) reports that
atmospheric entry will occur on 2008 Oct 07 0246
UTC over northern Sudan.
6
2008 October 6, about 18h UT Unusual Meteor
community (a.o. Dr. Jenniskens) is alerted.
Small asteroid Big meteoroid!
7
Over the course of 20 hours, the asteroids
position relative to the stars is measured some
570 times...
La Sagra Sky Survey - S. Sanchez et al., Mallorca
8
Orbit in space determined 10,000 times better
than typical orbit derived from few seconds long
bolide
  • Orbital elements (Steven R. Chesley)
  • a 1.308201 0.000009 AU
  • q 0.899957 0.000002 AU
  • i 2.54220 0.00004º
  • W 194.101139 0.000002º
  • w 234.44897 0.00008º J2000

9
Astronomical reflectance spectrum color of the
asteroid is gray A. Fitzsimmons and
collaborators (La Palma / U.K.)
10
Asteroid flickering tumbling and shapeR.
Dantowitz and M. Kozubal, Clay Center
Observatory, USA
11
(No Transcript)
12
Impact point in Nubian Desert of northern Sudan
Meteosat 8
In Kenya Distant rumble (Infrasound) P. Brown,
UWO
13
End of the story?
37-km explosion Apparently, object will not
survive passage through the atmosphere, no
fragments survived. Never before have meteorites
been recovered from such a high explosion. But
was this really the end of the meteor?
14
October - early November 2008Jenniskens
established contact with Dr. Muawia Shaddad
(University of Khartoum) to gather eye witness
accounts. Shaddad forwards images of train taken
by cell phone.
M. Elhassan
15
Cell phone images of train APOD Nov 8
16
2008 Dec. 4 Visit location of APOD train image
Mohamed Elhassan, Wadi Halfa
17
Train drift due to winds
Calculations by Jim Albers
Wadi Halfa
18
Sinking feeling...
  • Fireball had abrupt ending No big fragments
    emerged from the explosion below about 32 km
  • Search for small pieces?
  • These should have fallen close to explosion (deep
    into desert)
  • If anything small survived, it would be spread
    over huge area because, at this high altitude,
    the asteroid had not significantly slowed down.

19
Back at Station 6 Busload of students from U.
of Khartoum!
20
Next day take bus along freshly created30-km
long Asteroid Track
21
Start search just down range of explosion
22
Foot search required gravel plain,hard to see
small things far away...
23
Very end of day 1 They can be
found!Incredible - M. H. Shaddad
Mohammed Alameen
24
4 2nd day more scruffy black looking meteorites
25
3rd day they finally got bigger as they should,
but 29 km down track...
15
26
2009 Feb 27 - Mar 02 (back to Sudan) Peters
first find!
27
Almahata Sitta Consortiumhttp//asima.seti.org/20
08TC3/
  • Peter Jenniskens, SETI Institute
  • Muawia Shaddad, U. of Khartoum
  • Mike Zolensky, JSC
  • Doug Rumble, Carnegie Institute
  • Jon Friedman, Univ. Fordham, NY
  • Andrew Steele, Carnegie Institute
  • Scott Sandford, NASA Ames
  • Kees Welten, Berkeley
  • Rainer Weiler, Switzerland
  • Carla Taricco, Turin, Italy
  • Noriko Kita, Univ. Wisconsin-Madison
  • S.V.S. Murty, Navrangpura, India
  • U. Ott, MPI fuer Chemie, Mainz
  • Takahiro Hiroi, Brown Univ.
  • .
  • Reflection spectroscopy
  • Mass, type, density, XRF
  • SEM, EPMA, petrography
  • Oxygen isotopes
  • Bulk chemistry
  • Raman spectroscopy
  • Mid-IR transmission spectroscopy
  • Cosmic radio nucleides
  • Nobel gasses
  • Gamma-ray spectroscopy
  • SEM, EPMA, SIMS
  • Nobel gasses
  • Nobel gasses
  • Reflection spectroscopy
  • .

28
Lucky 7 first one analysed
29
7 broken along white layer tensile strength 56
26 MPastrength of asteroid (explosion)
0.2-0.3 MPa!
30
Meteorite spectrum asteroid spectrum(no
dust/sand on the surface)
31
Astronomical spectrum F
Average asteroid spectra by Takahiro Hiroi
32
Size 3-4 meter object
  • From brightness asteroid albedo gt size
  • Kinetic energy 6.4 x 1012 J (Albedo 0.046
    4.1m, assume density 2.3 g/cm3)
  • From acoustic signal
  • Kinetic energy 6.7 2.1 x 1012 J
  • Bolide light curve (Meteosat 8)
  • Kinetic energy 4 x 1012 J

33
Petrography anomalousData Mike Zolensky, NASA
JSC
34
Pores are lined with olivine crystals
35
Find out what type of meteorite this is from
oxygen isotopes
17 16
O/ O
18 16
O/ O
36
anomalous polymict Ureilite (an achondrite)!
(Data Doug Rumble, Carnegie Institution of
Washington)
17 16
O/ O
18 16
O/ O
37
Rare Earth Element abundances residue of partial
melt (Data Jon Friedman, Fordham University, NY)
lt chondrite
lt everything molten and sunk
38
Asteroid formation growing by collisions
39
Ureilites a brief history in the origin of
differentiated planets like Earth -on the cusp
of complete melting
Chondrite
Basaltic achondrite Iron meteorite
Ureilites
40
Asteroid evolution collisions, decay
41
Trail of crumbs trace F-class asteroids back to
their region of origin in the asteroid belt
Elongation of orbit (eccentricity)
Orbital period (semi-major axis)
42
The moral of the story...
  • As far as asteroids are concerned smaller can be
    better (but not easier).
  • As far as meteorite falls are concerned whole
    new game in town by following up on high
    explosions.
  • As far as meteorites are concerned Ureilites may
    finally be understood.
  • As far as impact location (Sudan) is concerned
    We couldnt have been more lucky with this one!

University of Khartoum staff and students Well
done!
43
  • The impact and recovery of asteroid 2008 TC3

P. Jenniskens et al., 2009. May 26 issue of
Nature
About PowerShow.com