20th
ALH84001
Historic meteorites in the 20th century? Sure. They may not be historic in terms of their age, but many have booked a place in the history books.
The Nakhla impact (Egypt, *1911), for instance. Not only was it alleged to have struck and killed a dog, it was subsequently discovered that it originated from an impact on the planet Mars. Indeed, a whole class of meteorites (Nahklites) are named after it.
Allende (Mexico, *1969) is still by far the largest recorded fall of carbonaceous material. It was used as test specimens for the NASA moon rock receiving labs.
ALH84001 – the “proof” of life on Mars, was recovered in Antarctica in 1984. Some ten years later, researchers claimed they had found evidence of fossilised Martian microbes trapped in the meteorite. The jury is still out.
Allende
Allende – Chihuahua,Mexico
Type – Stone ,Carbonaceous Chondrite
Class – (CV3)
Fell – Feb 8,1969
Fell in the area of Chihuahua, Mexico on Feb 9, 1969 The strewnfield is one of the biggest stone strewnfields ever recorded. Allende contains grains of dust from stars that existed long ago before our Solar System formed. This makes this meteorite one of the only meteorites truly containing “stardust”. Ancient stardust in meteorites helps explain the evolution of the our galaxy. Allende is one of the most studied meteorites in the world. So for, this the oldest thing man has ever touched, which dates 4.5 billion years old.
This meteorite is of a rarest type known, a carbonaceous chondrite (CV3 – only 16 examples of which are known). Carbonaceous chondrites are considered to represent the most primitive material in the solar system, and are of particular interest to planetary scientists, which formed during the evolution of the our galaxy.
The fine-grained grey matrix consists largely of the silicate mineral olivine, which hosts abundant spherical chrondrules and light colored clusters of minerals known as Calcium Aluminium Inclusions (CAIs). Both chondrules and CAIs formed when superheated dust in the solar nebula cooled, crystallising CAIs and then chodrules, 10 to 50 million years before larger objects such as our planet began to form. CAIs have been isotopically dated at 4.57 billion years old (4,570,000,000 years), making this meteorite the oldest thing you will ever hold.
Perhaps even more amazing is that scientists found tiny microdiamonds within the Allende Meteorite. Studies show that these tiny diamonds came from stars that existed before our solar system formed.
In 2009 from American Mineralogist, scientists have found a new mineral only present in Allende meteorite, which is called Tistarite.
The name of the new mineral is derived from the word “star” and the composition “Ti,” implying that this new mineral
is likely a condensate among the first solids formed in the solar system at the birth of our Sun.