Russian Meteor May Have Gangmates In Tow QuoteThe house-sized rock that exploded spectacularly in the skies near Chelyabinsk, Russia, in February may have been a member of a gang of asteroids that still poses a threat to Earth, a new study says. The evidence is circumstantial, but future observations could help to settle the question.
On 15 February, an 11,000-tonne space rock slammed into the atmosphere above Russia, producing the most powerful impact since the Tunguska explosion in 1908 — which may also have been caused by an asteroid — and generating a shock wave that damaged buildings and injured more than 1,000 people. The 18-metre-wide object could not be seen as it approached the planet because it was obscured by the Sun's glare, but observations made while it was in the atmosphere have enabled several groups of researchers to estimate its orbit2.
However, the estimates varied so much that there was no clear orbit that researchers could use to hunt for sibling asteroids on a similar path, say Carlos and Raúl de la Fuente Marcos, orbital dynamicist brothers at the Complutense University of Madrid.
They decided to tackle the problem with brute computational force, running simulations of billions of possible orbits to find the ones most likely to have led to a collision. They then used the average of the ten best orbits to search a NASA asteroid catalogue for known objects on similar paths. They found about 20, ranging in size from 5 to 200 metres across, they report in an article to be published in Monthly Notices of the Royal Astronomical Society: Letters1.
Broken family
The researchers propose that these rocks are pieces of a rubbly asteroid that came apart some time in the past 40,000 years. The break-up may have been triggered by stresses from temperature swings as the parent asteroid looped out past Mars and then back towards Venus on its travels around the Sun, says Carlos de la Fuente Marcos.
The rocky fragments could one day follow their planet-pummelling sibling to Earth, he says. "More objects with the same orbital signature may encounter our planet in the future." http://www.nature.com/news/russian-meteor-may-have-gangmates-in-tow-1.13498
On the website I have documents about 200 meteor craters on Earth... sooner or later a big one will hit again
Lets hope the Star Wars laser cannons Reagan built will stop them :D
Lets hope so Zorgon, would be a form of defense if this were the case.
Understanding how they figure these cosmic bodies out for impact scenarios is quite fascinating, and even becomes somewhat more alarming when we see such Magnitude probable cosmic missile's.
Here's the arithmetical trick for personal configuration's when such events occur:
QuoteConversion of Absolute Magnitude to Diameter
The following table lists the diameters of minor planets corresponding to the given values of the absolute magnitude, H. The diameter is to be read as kilometers when H is in the left-hand column, meters when in the middle column or millimeters when in the right-hand column. E.g., for a rocky body, H = 8.0 corresponds to a probable diameter range of 65 to 150 km , whereas H = 23.0 corresponds to a probable diameter range of 65 to 150 m. For icy bodies, the corresponding probable diameter ranges are 45 to 150 km and 45 to 150 m.
Conversion of H to a diameter for a specific object requires knowledge of the object's albedo. This quantity is not known for most objects, so the diameters listed here are given as ranges: the smallest value corresponding to an albedo of 0.5 (intended for icy objects), the middle value corresponding to an albedo of 0.25 and the larger to an albedo of 0.05. Most main-belt minor planet will have albedos in the range 0.05 to 0.25. If a specific object has an albedo < 0.05, the diameter will be larger than the upper limit listed here.
QuoteExplanation Of Symbols
The symbols used in the lists of unusual objects and on MPECs have the following meanings (for detailed descriptions of what the meanings mean, you are referred to standard texts on celestial mechanics):
Designation (and name)
For numbered minor planet, this column contains the object's number and name (if named).
Prov. Des.
This is the object's provisional designation. Note that some of the low-numbered objects have old-style provisional designations, where the letters were recycled without regard to the calendar.
Ln
For Trojans, this column indicates whether the minor planet is near the L4 or the L5 point of the planet. L4 is 60° preceding the planet and L5 is 60° following.
q
Perihelion distance (in AU).
Q
Aphelion distance (in AU).
EMoid/Earth MOID
The value (in AU) of the Earth MOID. This is the minimum distance between the orbit of the earth and the minor planet. The MOID value is for the earth (not the earth-moon barycenter) and is for the epoch of the minor-planet orbit. Note that the MOID does not give any information on actual close approaches--you should refer to lists of close encounters for such information. A value less than the radius of the earth does NOT indicate that a hit will occur.
H
Absolute visual magnitude. A table converting H to a diameter range is available.
Epoch, M
These columns give the value of the mean anomaly for the specified epoch (in YYYYMMDD format).
Peri., Node, Incl.
The angular J2000.0 elements of the orbit, in degrees: argument of perihelion, longitude of the ascending node and inclination.
e
Orbital eccentricity.
a
Semimajor axis (in AU).
Opps.
Number of oppositions at which the object has been observed. If observations have been made at one opposition only, the arc length in days is given in parentheses.
Ref.
Reference to the published orbit, generally to the MPCs (= Minor Planet Circulars), MPOs (= Minor Planet Circulars Orbit Supplement) or Icarus.
Types of Object
NEAs are Near-Earth Asteroids. NEOs are Near-Earth Objects (including both asteroids and comets). The definitions for the various classes of NEA differ between different sources. Here, the following definitions are used: Atens have semimajor axes, a, less than 1 AU; Apollos have semimajor axes, a, greater than 1 AU, and perihelion distances, q, less than 1 AU; and Amors have perihelion distances between 1 and 1.3 AU.
PHA
PHAs are potentially-hazardous objects. These are objects with H brighter than V = 22 and an Earth MOID less than 0.05 AU.
Some other quantities were given on older lists.
M+, M-
The perpendicular distance to the earth's orbit when an object is at the earth's distance from the sun (in AU, omitted if greater than 0.3 AU). These quantities are given only for objects with perihelion distances less than 1.05 AU, although they are physically meaningful only when the orbit of an object intersects that of the earth. For Amor objects with perihelion distances less than 1.05 AU, a single value spans the two columns. For more information on these quantities, see Marsden, B. G. (1993) To Hit Or Not To Hit. In Proceedings of the Near-Earth-Object Interception Workship, pp. 67-71. Eds. G. H. Canavan, J. C. Solem and J. D. G. Rather. Los Alamos National Laboratory.
N+, N-
The distances of an object's nodal points from the earth's orbit (in AU, omitted if greater than 0.3 AU). N+ refers to the distance from the ascending node, N- to the distance from the descending node. These quantities are only given for objects with perihelion distances less than 1.3 AU. For more information on these quantities see Marsden (1993, ibid.).
Min.
This quantity, in AU and given only in the list of the larger potentially dangerous minor planets, is the minimum value of N+, N-, M+ and M-. If the minimum value corresponds to one of the value of N, it is followed by a `D' (to denote that the minimum value occurs at the descending node) or by an `A' (to denote that the minimum value occurs at the ascending node). Note that quantity does not give any information on actual close approaches--you should refer to lists of close encounters for such information. A value of 0.000 does NOT indicate that a hit will occur.
The following table lists the predicted encounters by Potentially Hazardous Asteroids (PHAs) to within 0.05 AU of the earth from the start of this year through 2178. (http://www.minorplanetcenter.net/iau/lists/PHACloseApp.html)
Plot of the Innermost Solar System (http://www.minorplanetcenter.net/iau/lists/InnerPlot2.html)
List Of The Potentially Hazardous Asteroids (PHAs) (http://www.minorplanetcenter.org/iau/lists/Dangerous.html)
Always suffice to deduce our local flying rocks for true deductive realization of just how many we have in our neighborhood at any given time.
Why Russia seems to get these type of events has yet to be figured out, but as many have attested with these event's "Eventually" the big one will come in, and not much more that we can do at this point.
The PHA of the 2011 E040 is the next big thing I do believe, is a fascinating time to be watching the skies for sure.
1WW
ETA: Highlight text descriptions
I am still not totally convinced that the "Russian Meteor" was not the lost NSA space plane, the X37, or what ever they call it. Unless you all have totally ruled that out and I missed it? :-\
Quote from: Phedre on August 05, 2013, 07:22:48 PM
I am still not totally convinced that the "Russian Meteor" was not the lost NSA space plane, the X37, or what ever they call it. Unless you all have totally ruled that out and I missed it? :-\
The X-37B: Exploring expanded capabilities for ISS missions
March 12, 2013 by Chris Gebhardt (http://www.nasaspaceflight.com/2013/03/x-37b-expanded-capabilities-iss-missions/)
QuoteThe United States' X-37B robot mini-shuttle spaceplane, which was launched into orbit on a classified mission in April, has changed its orbit. However the "secret space warplane" - as the X-37B has been dubbed by the Iranian government - has now been re-acquired by alert amateur skywatchers.
24th August 2010
Secret X-37B space plane lost by sat-spotters for 2 weeks (http://www.theregister.co.uk/2010/08/24/x37b_orbit_change/)
I can't find anything really more recent than the March 12, 2013 article, but , for some reason, I am not convinced it is the X-37B Phage, there would have been something on the lines of debris field, and they can't even find an impact-or fragment as of right now. so, Hard too say, not a Post I was expecting for this thread ... LOL Thinking out side the box are we? :P
1WW
Quote from: Phedre on August 05, 2013, 07:22:48 PM
I am still not totally convinced that the "Russian Meteor" was not the lost NSA space plane, the X37, or what ever they call it. Unless you all have totally ruled that out and I missed it? :-\
X-37B is officially OTV-3 (3 being the mission number...) also designated USA-240
The Russian meteorite has benn found in several hundred pieces but th dang Russians are asking too much for it :P