Don Yeomans, Paul Chodas, Steve
Chesley & Jon Giorgini
NASA/JPL Near-Earth Object Program Office
January 12, 2010
Asteroid 2010 AL30, discovered by the
LINEAR survey of MIT's Lincoln Laboratories on Jan. 10,
will make a close approach to the Earth's surface to
within 76,000 miles on Wednesday January 13 at 12:46 pm
Greenwich time (7:46 EST, 4:46 PST). Because its orbital
period is nearly identical to the Earth's one year
period, some have suggested it may be a manmade rocket
stage in orbit about the Sun. However, this object's
orbit, reaches the orbit of Venus at its closest point
to the Sun and nearly out to the orbit of Mars at its
furthest point, crossing the Earth's orbit at a very
steep angle, and this actually makes it very unlikely
that 2010 AL30 is a rocket stage. Furthermore, our
trajectory extrapolations show that this object cannot
be associated with any recent launch and it has not made
any close approaches to the Earth since well before the
Space Age began.
It seems more likely that this is a
near-Earth asteroid about 10-15 meters across, one of
approximately 2 million such objects in near-Earth
space. One would expect a near-Earth asteroid of this
size to pass within the moon's distance about once every
week on average.
To take advantage of this close
approach, there are plans to observe it with the
Goldstone planetary radar on Wednesday evening, Jan. 13
beginning at 6:20 PST. The radar data could dramatically
improve the object's orbit and provide additional
information on its size and shape.
Small Asteroid 2009 VA Whizzes By The Earth
November 9, 2009
A newly discovered asteroid designated 2009 VA,
which is only about 7 meters in size, passed about 2 Earth radii
(14,000 km) from the Earth's surface Nov. 6 at around 16:30 EST.
This is the third-closest known (non-impacting) Earth approach
on record for a cataloged asteroid.
Don Yeomans, Paul Chodas, Steve Chesley
NASA/JPL Near-Earth Object Program Office
October 23, 2009 On October 8, 2009
about 03:00 Greenwich time, an atmospheric fireball blast was
observed and recorded over an island region of Indonesia. The
blast is thought to be due to the atmospheric entry of a small
asteroid about 10 meters in diameter that, due to atmospheric
pressure, detonated in the atmosphere with an energy of about 50
kilotons (the equivalent of 110 million pounds of TNT
explosives).
The blast was recorded visually and reported
upon by local media representatives.
A report from Elizabeth Silber and Peter Brown
at the University of Western Ontario indicates that several
international very-long wavelength infrasound detectors recorded
the blast and fixed the position near the coastal city of Bone
in South Sulawesi, island of Sulewesi. They note that the blast
was in the 10 to 50 kT range with the higher end of this range
being more likely.
Assuming an estimated size of about 5-10
meters in diameter, we would expect a fireball event of this
magnitude about once every 2 to 12 years on average. As a rule,
the most common types of stony asteroids would not be expected
to cause ground damage unless their diameters were about 25
meters in diameter or larger.
FROM THE JAKARTA GLOBE
OCTOBER 8, 2009
Mysterious
Explosion Panics Locals in South Sulawesi, Police Still
Investigating
A large explosion was
reported in Latteko, Bone district, South Sulawesi, on
Thursday morning at around 11 am and may have been a plane
crash. Locals at first thought it was an earthquake and ran
out of their homes in panic.
Bone Police spokesman Abunawas confirmed the large
explosion.
“We received a report from locals that there was a plane
crash in Latteko, Bone, South Sulawesi, but we are still
investigating,” Abunawas said.
The explosion was heard from up to 11 kilometers away.
“We keep receiving phone calls from concerned locals who are
curious to know what the big bang was,” he said.
Meanwhile, a local named Nur Pairah who works as a teacher
in Bone told Metro TV that when the explosion happened she
was inside a classroom. She thought it was the sound of
thunder. Thinking it might be an earthquake, Nur Pariah
ordered her students to evacuate.
Police are coordinating with the Geophysics, Climatology and
Meteorology Agency to confirm whether or not the explosion
was an earthquake.
Elizabeth Silber and Peter Brown
Meteor Infrasound group, Dept. of Physics and Astronomy, Univ.
of Western Ontario, London, ON, N6A 3K7, CANADA
Released: October 19, 2009
Based on these initial reports, a detailed
examination was made of all International Monitoring System (IMS)
infrasound stations of the Comprehensive Nuclear-Test-Ban Treaty
Organization (CTBTO). From this initial examination, a total of
11 stations showed probable signals from a large explosion
centered near 4.5S, 120E, with an origin time near 0300 UT on
Oct 8, 2009, consistent with the media reports. This signal was
notable for having been (a) detected at many IMS stations,
including five at ranges over 10,000 km (and one at a nearly
18,000 km range) and (b) being confined to very low frequencies.
Both of these observations suggest the explosion source was of
very high total energy. All signal motions were between 0.27 -
0.32 km/s, consistent with stratospheric signal returns.
We have used the Air Force Technical
Application Centre (AFTAC) period-yield relation as described by
ReVelle (1997) as the most robust basic indicator of source
energy. To generate measured periods, the average periods of all
phase-aligned stacked waveforms at each station were measured,
according to the technique described in Edwards et al (2006).
These periods were then averaged to produce a single, global
average period of 13.4 sec and the AFTAC yield relation applied;
this produced an average source yield of 31 kT of TNT. Averaging
the individual yields from all stations produces a mean source
energy near 50 kT of TNT while using only the eight stations
having the highest signal-to-noise-ratio (SNR) and using the
local observed periods of the waveform at maximum amplitude
produces a yield estimate of 40 kT of TNT, all of which are
basically consistent. It is important to note, however, that the
standard deviation of this measurement is nearly 30 kT. That is,
the best source energy estimate would be 40 +/- 30 kT TNT. Note
that much of this variation may be due to the signal emanating
from different portions of the fireball trail as observed at
different stations; each period measurement is a "sample" of the
size of the cylindrical blast cavity at that particular segment
of the trail detected by any one station. As such, the out of
atmosphere yield for this event is likely higher than these
measurements suggest - very probably in the ~50 kT range.
The yield estimates based on infrasonic
amplitude are very uncertain in this instance as the propagation
distances are much larger than is typical and outside the range
limits where such relations have been developed (e.g. Edwards et
al, 2006) and hence the period relationship (which was generated
using a dataset of nuclear explosions having yields in this
range) is more applicable.
Some examples of the detected and processed
waveforms are shown in the appendix.
Based on these infrasound records, it appears
that a large (40-50 kT TNT) bolide detonation occurred near 0300
UT on Oct 8, 2009 near the coastal city of Bone in South
Sulawesi, Indonesia. The infrasonic geolocation is not precise
enough to determine if the bolide was over water or land, but it
was relatively near the coast.
Follow-on observations from other instruments
or ground recovery efforts would be very valuable in further
refining this unique event.
Using an average impact velocity for NEAs of
20.3 km/s, the energy limits (10 - 70 kT) suggested by this
analysis correspond to an object 5-10 m in diameter. Based on
the flux rate from Brown et al (2002), such objects are expected
to impact the Earth on average every 2 - 12 years.
NASA
Refines Asteroid Apophis' Path Toward Earth October 7, 2009
Using updated information, NASA scientists have
recalculated the path of a large asteroid. The refined path
indicates a significantly reduced likelihood of a hazardous
encounter with Earth in 2036.
The Apophis asteroid is approximately the size
of two-and-a-half football fields. The new data were documented
by near-Earth object scientists Steve Chesley and Paul Chodas at
NASA's Jet Propulsion Laboratory in Pasadena, Calif. They will
present their updated findings at a meeting of the American
Astronomical Society's Division for Planetary Sciences in Puerto
Rico on Oct. 8.
Report:
Deflecting a Hazardous Near-Earth Object April 2009
This short report on Near-Earth Object (NEO)
hazard mitigation strategies was developed in response to a
request for information by the U.S. National Research Council's
Space Sciences Board on December 17, 2008 and for the
Planetary Defense Conference that took place 27-30 April
2009 in Granada Spain. Although we present example simulations
for specific techniques that could be employed to deflect an
Earth threatening NEO, our primary goal is to discuss some of
the general principles and techniques that would be germane to
all NEO deflection scenarios. This report summarizes work that
was carried out in early 2009 and extends an earlier,
more detailed
study carried out in late 2008. The complete report is
available here (Word
Document - 316K)
NASA Team Finds Riches in Meteorite
Treasure Hunt March 30, 2009
For the first time, scientists are studying
recovered celestial meteorites that have a definitive link with
an asteroid from space. This presents the science community an
unprecedented opportunity to interpret asteroid data and learn
more about the origins and differentiations between asteroids
and may provide better answers about the formation of our solar
system.
Asteroid 2008
TC3 Strikes Earth: Predictions and Observations Agree
November 4, 2008
A spectacular fireball lit up the predawn sky
above Northern Sudan on October 7, 2008. This explosion was
caused by the atmospheric entry of a small near-Earth asteroid,
estimated to be no more than a few meters in diameter. Although
such small impact events occur several times per year around the
globe, this case was unprecedented because the asteroid was
actually discovered the day before it reached the Earth and the
impact location and time were for the first time predicted in
advance.
This is a scholarly
work for non-profit educational purposes. Presented
FREE to students, teachers & educators, and the public in the
interest of developing awareness of the subject and in helping to
preserve our common heritage. Some content is public domain, some
content used under "Fair Use" provision of section 107 U.S.
Copyright Law. Some content from third-parties. All third-party
copyrights acknowledged. Sources credited where possible or known.
If we have not correctly credited a source - please let us know. You may road and traffic signs at
your own risk.
We do not
request or use ANY personally identifiable information on this
website, nor do we collect such information.
We use
third-party advertising companies to serve ads when you visit
our website. These companies may use information (not including
your name, address, email address, or telephone number) about
your visits to this and other websites in order to provide
advertisements about goods and services of interest to you.
Google, as a
third party vendor, uses cookies to serve ads on this site.
Google's use of
the DART cookie enables it to serve ads to our users based on
their visit to our sites and other sites on the Internet.
This website is
presented in the public interest! The author makes no assertions
about the fact or fiction of its content. The information presented is believed to be correct and
accurate, but we accept no liability for the accuracy of this
information. However, please let us know of any errors. Use this
website at your own risk. We present the above in the public
interest, but recognize that some of the content may be disturbing
to some views - discretion is advised.
All Website Names,
Doom2036 (in any form), Destinesia (in any form),
DoctorStrangerWeather (in any form), Dr. Strange Weather (in any
form), Doctor Strange Weather (in any form), MentalWardPublishing
(in any form), McGuinnessPublishing (in any form),
McGuinnessDomains, (in any form), WebFossil (in any form) are all
Trademarks of Tim McGuinness, Ph.D. Copyright 2004-2009 Tim
McGuinness, Ph.D. - All Rights Reserved Worldwide & Webwide
Please
send any comments to: wesayso @ mcguinnessPublishing . com
Our Websites are
dedicated to: Kyra, and the whole McFamily! Past, Present, and
Future - Here, There, and Everywhere! And to friends in Florida,
Spain, Costa Rica, Central America, Scotland, Peru, Colombia,
Philippines, and a Land Down Under - You know who you are!
Our Websites are dedicated
to:
Kyra, Flare, and the whole McFamily!
Past, Present, and Future - Here, There, and Everywhere! And to
friends in Tarpon Springs, Florida, Spain, Costa Rica, Central
America, Scotland, and a Land Down Under - You know who you are!
The term Doom2036, as well as the domain names
Doom2036.com are Trademarks of Tim McGuinness, Ph.D.
Copyright 2008-2010 Tim McGuinness, Ph.D. - All Rights Reserved Worldwide & Webwide
Please send any
comments to: wesayso
@
McGuinnessPublishing
.
com
Report:
Deflecting a Hazardous Near-Earth Object 
