Yahoo Web Search

  1. About 190,000 search results
  1. A Martian meteorite is a rock that formed on Mars, was ejected from the planet by an impact event, and traversed interplanetary space before landing on Earth as a meteorite. As of September 2020 [update] , 277 meteorites had been classified as Martian, less than half a percent of the 72,000 meteorites that have been classified.

    • History

      By the early 1980s, it was obvious that the SNC group of...

    • Subdivision

      As of April 25, 2018, 192 of the 207 Martian meteorites are...

    • Origin

      The majority of SNC meteorites are quite young compared to...

    • Possible evidence of life

      Several Martian meteorites have been found to contain what...

  2. This is a list of Martian meteorites i.e. meteorites that have been identified as having originated from Mars.. Of the over 53,000 meteorites that have been found on Earth just 99 had been identified as Martian as of 30 July 2011.

  3. Tissint meteorite. The Tissint meteorite is a Martian meteorite that fell in Tata Province in the Guelmim-Es Semara region of Morocco on July 18, 2011. Tissint is the fifth Martian meteorite that people have witnessed falling to Earth, and the first since 1962. Pieces of the meteorite are on display at several museums, including the Museum of ...

  4. People also ask

    What did scientists find in the Martian meteorite?

    Is there evidence of life on Martian meteorites?

    Are all the 'Martian' meteorites from Mars?

    What do Martian neteorites tell us about Mars?

  5. en.wikipedia.org › wiki › MeteoriteMeteorite - Wikipedia

    • Fall Phenomena
    • Classification
    • Chemistry
    • Weathering
    • Collection
    • in Human Affairs
    • Notable Examples
    • External Links

    Most meteoroids disintegrate when entering the Earth's atmosphere. Usually, five to ten a year are observed to fall and are subsequently recovered and made known to scientists. Few meteorites are large enough to create large impact craters. Instead, they typically arrive at the surface at their terminal velocityand, at most, create a small pit. Large meteoroids may strike the earth with a significant fraction of their escape velocity (second cosmic velocity), leaving behind a hypervelocity impact crater. The kind of crater will depend on the size, composition, degree of fragmentation, and incoming angle of the impactor. The force of such collisions has the potential to cause widespread destruction. The most frequent hypervelocity cratering events on the Earth are caused by iron meteoroids, which are most easily able to transit the atmosphere intact. Examples of craters caused by iron meteoroids include Barringer Meteor Crater, Odessa Meteor Crater, Wabar craters, and Wolfe Creek cra...

    Most meteorites are stony meteorites, classed as chondrites and achondrites. Only about 6% of meteorites are iron meteorites or a blend of rock and metal, the stony-iron meteorites. Modern classification of meteorites is complex. The review paper of Krot et al. (2007)summarizes modern meteorite taxonomy. About 86% of the meteorites are chondrites, which are named for the small, round particles they contain. These particles, or chondrules, are composed mostly of silicate minerals that appear to have been melted while they were free-floating objects in space. Certain types of chondrites also contain small amounts of organic matter, including amino acids, and presolar grains. Chondrites are typically about 4.55 billion years old and are thought to represent material from the asteroid belt that never coalesced into large bodies. Like comets, chondritic asteroids are some of the oldest and most primitive materials in the Solar System. Chondrites are often considered to be "the building b...

    In March 2015, NASA scientists reported that complex organic compounds found in DNA and RNA, including uracil, cytosine, and thymine, have been formed in the laboratory under outer space conditions, using starting chemicals, such as pyrimidine, found in meteorites. Pyrimidine and polycyclic aromatic hydrocarbons (PAHs) may have been formed in red giants or in interstellar dustand gas clouds, according to the scientists. In January 2018, researchers found that 4.5 billion-year-old meteorites found on Earth contained liquid water along with prebiotic complex organic substances that may be ingredients for life. In November 2019, scientists reported detecting sugar molecules in meteorites for the first time, including ribose, suggesting that chemical processes on asteroids can produce some organic compounds fundamental to life, and supporting the notion of an RNA world prior to a DNA-based origin of lifeon Earth.

    Most meteorites date from the early Solar System and are by far the oldest extant material on Earth. Analysis of terrestrial weatheringdue to water, salt, oxygen, etc. is used to quantify the degree of alteration that a meteorite has experienced. Several qualitative weathering indices have been applied to Antarctic and desertic samples. The most commonly employed weathering scale, used for ordinary chondrites, ranges from W0 (pristine state) to W6(heavy alteration).

    A "meteorite fall", also called an "observed fall", is a meteorite collected after its arrival was observed by people or automated devices. Any other meteorite is called a "meteorite find". There are more than 1,100 documented falls listed in widely used databases, most of which have specimens in modern collections. As of January 2019[update], the Meteoritical Bulletin Databasehad 1,180 confirmed falls.

    Meteorites have figured into human culture since their earliest discovery as ceremonial or religious objects, as the subject of writing about events occurring in the sky and as a source of peril. The oldest known iron artifacts are nine small beads hammered from meteoritic iron. They were found in northern Egypt and have been securely dated to 3200 BC.

    Naming

    Meteorites are always named for the places they were found, where practical, usually a nearby town or geographic feature. In cases where many meteorites were found in one place, the name may be followed by a number or letter (e.g., Allan Hills 84001 or Dimmitt (b)). The name designated by the Meteoritical Societyis used by scientists, catalogers, and most collectors.

    Extraterrestrial

    1. Block Island meteorite and Heat Shield Rock – Discovered on Mars by Opportunity rover among four other iron meteorites. Two nickel-iron meteorites were identified by the Spirit rover. (See also: Mars rocks) 2. Bench Crater meteorite (Apollo 12, 1969) and the Hadley Rille meteorite (Apollo 15, 1971)−Fragments of asteroids were found among the samples collected on the Moon.

    Disintegrating meteoroids

    1. Tunguska event in Siberia1908 (no crater) 2. Vitim eventin Siberia 2002 (no crater) 3. Chelyabinsk eventin Russia 2013 (no known crater)

    • Untitled Comment 2
    • ALH84001
    • Determination That Meteorite Is from Mars
    • Page Needs Renaming
    • Number of Specimens
    • Comment on The History Section
    • New Section on Cosmic Radiation Exposure Ages
    • How A Martian Meteorite Can Have Escaped The Martian Gravity field?
    • CK Beauty, The Oldest Known Martian Meteorite Is Older Than 2.1 Billion Years
    • A New Standard For The Minimum Size of A life-form?

    Is there any source for this paragraph? "It should be pointed out, however, that the isotope ratios do not actually match Mars ratios especially well, to the extent that Mars ratios are known..." And this: "Although common wisdom is that the SNC meteorites are from Mars, the Mars origin theory does have some problems. The isotope ratios are not an especially good match. A widely published graph showing a near-perfect match is alleged to be constructed from examples selected to "prove" the hypothesis and to be a poor representation of the real data. For example, the Ar40/Ar36 ratio for one meteorite (1650) is almost exactly half-way between Earth (300) and Mars (3000). Carbon dioxide, the predominant gas in the current Mars atmosphere, is unaccountably rare in the trapped gases in the SNC meteorites. The SNC meteorites do not show shock artifacts that would be expected in small objects ejected with enough velocity to escape Mars. The majority of SNC meteorites are quite young by geol...

    In the article ALH84001 is described as a shergottite, but I don't know of anyone in the planetary science community who would classify it that way. McSween and Treiman [1998] says, "this meteorite does not fit into any of the previously established SNC categories." It should probably be its own category.--Will.i.am21:52, 19 September 2006 (UTC)

    It is not clear to me how this is determined. Could they possibly be from another planet, moon, or other body? Also, has any meteorite from Venus, Mercury, or the moons of Jupiter ever been found? --Eraticus04:20, 21 April 2007 (UTC) They're definitely from Mars - I'll add a section explaining all this. As for your question, there's tonnes of meteorites known from the Moon, and a few (Angrites) that *might* be from Mercury. Venus meteorites should be impossible, and there are no candidates anyway. This page is a bit messy, I'll give it a proper overhaul when I get the time - just finished a master's project on the Shergottites so I've got a reasonable idea what's going on... Ezkerraldean (talk) 13:54, 6 June 2010 (UTC)

    Although there are a few prominent NASA websites that call these objects Mars meteorites, e.g., http://www2.jpl.nasa.gov/snc/ and http://curator.jsc.nasa.gov/antmet/mmc/, the overwhelming usage among scientists is martian meteorites. In the NASA ADS bibliographic website, there are 26 publications listed that use the former term in the title and 636 publications that use the latter. In light of this, there is little doubt about the preferred term, so this page should be renamed. Unless there are reasonable objections that I can't think of, I will rename it. JeffG (talk) 01:21, 7 April 2010 (UTC)

    There is now about 110 specimens according to this article: Meteorite From Mars is Water-Rich. Danrok (talk) 21:06, 3 January 2013 (UTC) 1. The reference given for the 99 number is now showing 114. Perhaps we should update this number (and date), and expect to have to do this again in a few years. Watchwolf49z (talk) 00:37, 9 January 2013 (UTC) 1. 1.1. Done - Would someone please review the edit, I made a few changes to the prose that should be looked at. That dataBase gives the 61,000 number as well. This is really one of the best articles I come across in a while, especially concerning HIGHLY controversial subject material. Well done !!! Watchwolf49z (talk) 15:01, 12 January 2013 (UTC)

    This section states the following, "Then in 1983, various trapped gases were reported in impact-formed glass of the EET79001 shergottite, gases which closely resembled those in the martian atmosphere as analyzed by Viking. These trapped gases provided direct evidence for a martian origin." The last sentence that the trapped gasses provide direct evidence is not true since it cannot be proven merely from the resemblence to the current Martian atmosphere that they (the trapped gasses) actually came from it; especially from an object with an undetermined time of origin. (The article goes on to give speculations about when shergottites were actually formed.) It seems to me that you cannot obtain facts from speculations, no matter how reasonable they might be. This is not to say the meteorites could not have come from Mars, or even that it is unlikely that they have. But, based on what is written in this article, there is still no direct evidence. Skinnerd (talk) 15:59, 8 January 2013 (U...

    I came here looking for this information and didn't find anything, so added a table based on a 2006 book about meteorite exposure ages which has a section on Martian meteorites. It's obviously just a starting point and needs to be updated with the most recent research. Since they all originate apparently from only a few distinct impact events, I feel that it shouldn't be too much overload to the article to have a complete table of all the exposure ages determined so far. Robert Walker (talk) 09:41, 14 July 2013 (UTC)

    Can it be a volcanic object project with a velocy superior to the escape velocity.If no. What else? — Preceding unsigned comment added by 87.231.74.157 (talk) 12:59, 17 October 2013 (UTC) 1. Yes. I would like to know the escape velocity to go from Mars to Earth. --Error (talk) 00:58, 30 July 2018 (UTC)

    News article says it is 4.4 billion years old: http://edition.cnn.com/2013/11/20/tech/innovation/mars-meteorite/ — Preceding unsigned comment added by 141.135.9.205 (talk) 12:03, 22 November 2013 (UTC)

    The evidence for life on martian meteorites has been largely discounted because "the structures are too small to be Earthly bacteria." This is flawed for two reasons: 1. It has already been established that the meteorite is not from Earth. Consequently, what is possible on Earth should not constitute what is possible on Mars. Micropaleontologist Schopf also commented that, "the structures don't look especially like lifeforms to him." This statement should be deleted, as opinions aren't worth much in science. 2. According to an article published in Nature Communications, (6, Article number: 6372) "Diverse uncultivated ultra-small bacterial cells in groundwater", Bacteria from phyla are widespread in natural systems and some have very small genomes. Metagenomic analysis of groundwater that passed through a ~0.2-μm filter reveals a wide diversity of bacteria from the WWE3, OP11 and OD1 candidate phyla. Cryogenic transmission electron microscopy demonstrates that, despite morphological...

  6. NWA 7034 is the first Martian meteorite that is a breccia and does not fall in any of the known Martian meteorite groups (shergottite, nakhlite, chassignite and ALH 84001). NWA 7034 was classified as an ungrouped planetary achondrite until the Meteoritical Society approved the new designation "Martian (basaltic breccia)" in January 2013.

  1. People also search for