Martian Meteorite - Origin

Origin

The majority of SNC meteorites are quite young compared to most other meteorites and seem to imply that volcanic activity was present on Mars only a few hundred million years ago. The young formation ages of martian meteorites was one of the early recognized characteristics that suggested their origin from a planetary body such as Mars. Among martian meteorites, only ALH 84001 has a radiometric age older than about 1400 Ma (Ma = million years). All nakhlites, as well as Chassigny and NWA 2737, give similar if not identical formation ages around 1300 Ma, as determined by various radiometric dating techniques. Formation ages determined for many shergottites are variable and much younger, mostly ~150-575 Ma. The chronological history of shergottites is not totally understood, and a few workers have suggested that some may actually have formed prior to the times given by their radiometric ages, a suggestion not accepted by most workers. Formation ages of SNC meteorites are often linked to their cosmic-ray exposure (CRE) ages, as measured from the nuclear products of interactions of the meteorite in space with energetic cosmic ray particles. Thus, all measured nakhlites give essentially identical CRE ages of approximately 11 Ma, which when combined with their possible identical formation ages indicates ejection of nakhlites into space from a single location on Mars by a single impact event. Some of the shergottites also seem to form distinct groups according to their CRE ages and formation ages, again indicating ejection of several different shergottites from Mars by a single impact. However, CRE ages of shergottites vary considerably (~0.5-19 Ma), and several impact events are required to eject all the known shergottites. It has been asserted that there are no large young craters on Mars that are candidates as sources for the martian meteorites, but recent research claims to have a likely source for ALH 84001 and a possible source for other shergottites.

Read more about this topic:  Martian Meteorite

Other articles related to "origin, origins":

Jade Emperor - Chinese Mythology - Origin
... After 1,550 kalpas, each kalpa lasting for 129,600 years, he attained Golden Immortality ... After another one hundred million years of cultivation, he finally became the Jade Emperor ...
2006 State Of Origin Series
... The 2006 State of Origin series was the 25th year that the annual best-of-three series of interstate rugby league football matches between the Queensland and New South Wales representative ...
Origin Of Language - History - History of Research
... The question of language origins seemed inaccessible to methodical approaches, and in 1866 the Linguistic Society of Paris famously banned all discussion of the origin of ... However, scholarly interest in the question of the origin of language has only gradually been rekindled from the 1950s on (and then controversially) with ideas such as universal grammar, mass ... The "origin of language" as a subject in its own right emerged out of studies in neurolinguistics, psycholinguistics and human evolution ...
Origin - Other Uses
... early Christian scholar and theologian Origins Game Fair, an annual board game event in Columbus Ohio Origins Award, presented by the Academy of Adventure Gaming Arts and Design at the Origins ...
Walk-in - Origin
... Subsequently, a belief system grew up around the walk-in ... It included New Age attributes such as the concept of ascending into higher frequencies of evolution, a variety of psi powers, traditional "predictions regarding Earth Changes" first cited in the Bible (Book of Daniel and the Book of Revelation) but popularized by Edgar Cayce, and predictions of dire fates for those whose vibrational levels remain unraised ...

Famous quotes containing the word origin:

    The real, then, is that which, sooner or later, information and reasoning would finally result in, and which is therefore independent of the vagaries of me and you. Thus, the very origin of the conception of reality shows that this conception essentially involves the notion of a COMMUNITY, without definite limits, and capable of a definite increase of knowledge.
    Charles Sanders Peirce (1839–1914)

    Though I do not believe that a plant will spring up where no seed has been, I have great faith in a seed,—a, to me, equally mysterious origin for it.
    Henry David Thoreau (1817–1862)

    In the woods in a winter afternoon one will see as readily the origin of the stained glass window, with which Gothic cathedrals are adorned, in the colors of the western sky seen through the bare and crossing branches of the forest.
    Ralph Waldo Emerson (1803–1882)