Lunar Highlands - Classic Riker Box Specimens
Lunar Highlands - Classic Riker Box Specimens
Rare Lunar Meteorite Material!
The Moon has captured the human eye for millennia. It hangs in the night sky as Earth's singular and beautiful natural satellite. Our moon is uncommonly large proportional to our planet, a fact owed to its likely origin as an asteroid. When we look up to it, we can see the light "terra" and dark "mare," both sections of igneous rock.
This specimen is a hand-crafted resin "moon" containing lunar dust material. It comes from the lunar meteorite NWA 5000 and has been crafted to replicate the shape of our nighttime neighbor. The material's geologic composition has been determined to have come from the lighter highlands of the Moon.
From the Moon to your Hand
3,200,000,000 years ago, an asteroid struck the surface of the Moon. Immediately, a mass of rock, dust, and other regolith material was ejected from the ground. Most of this material likely fell back to the surface, but due to the Moon's low gravity, one piece managed to fly so high it escaped into outer space. Eventually, it was caught up in Earth's own orbit and was pulled down to our planet as a burning meteorite.
This meteorite is known as NWA 5000 and is part of a unique class of meteorites called a "lunaite." While most impactors that land on Earth come from the Asteroid Belt, this amazing specimen actually comes from the surface of the Moon. It is made up of highland anorthosite which tells us it came from the brighter colored sections of the Moon's surface.
📸 Macro Shot of the Lunar Material
This specimen is a handcrafted “moon” composed of fine-grained dust extracted from lunar meteorite NWA 5000. It has been prepared in a resin circle that represents the heavily cratered face of the Moon.
Each specimen is hand crafted and may exhibit differences in placement and texture. The specimen is enclosed in a handsome, glass-topped riker box case measuring 4 1/2" x 3 1/2". A small information card which serves as the authenticity statement is also included.
One of the largest lunar meteorites, NWA 5000 is a gabbroic rock typical of highlands origin with evidence of impact melt. Argon isotopes indicate the mass crystalized after a large impact 3.2 billion years ago, then experienced a second impact just 500 million years ago which ejected it into space, sending it on a relatively quick trip to Earth.
Meteorite age: 3,2000,000,000 years old
MORE ABOUT THE LUNAR HIGHLANDS
📸 Giovanni Battista Riccioli's Almagestum Novum (1651)
Mapping the Moon
It might be hard to imagine volcanoes on the Moon, but evidence of an active volcanic past covers our neighbor's cratered surface. More recent studies suggest the moon may still have a little life in it yet!
When looking at the Moon on a clear night with the naked eye, one is struck by contrasting shades of light and dark. In the autumn of 1609, Galileo Galilei created a series of watercolors based on his observation of the Moon through his telescope. Decades later, this landscape inspired astronomer Giovanni Battista Riccioli to give specific names to detailed features in Almagestum Novum (1651) and associating large regions with "Terra" and "Mare" (land and sea in Latin).
These regions are marked by the contrasting tones of color present on the lunar surface. The lighter terra is made up of igneous rocks and are sometimes referred to as the “highlands”, while the darker mare is composed of basalts. Both of these lands were formed by volcanic eruptions, with the highlands being older eruptions and the mare being more recent discharges.
The lunar highlands are made up of bright hills and domes, dominated by a range of intrusive igneous rocks which formed as large plumes of magma cooled. This occurred relatively close to the origin of the moon, laying a foundation of anorthosite rock.
When the Moon's "seas" were named, it was believed they were just as they appeared to be, vast oceans of water harbored on the lunar surface. Riccioli’s astronomical work ran parallel to his theological work, as the study of space was the study of God’s creation. Today we know that the dark spots are actually massive zones of basalt. As it turns out, referring to the dark spots of the moon as its seas was not so far from the truth. Billions of years ago, they were formed by the cooling of massive lava flows, hot oceans of molten rock.
The last major volcanic outflows on the Moon peaked about 3.2 billion years ago, but recent studies show that smaller outflows have taken place as recently as 100 million years ago. As with volcanoes here on earth, the flood basalts also leave behind lava tubes, natural conduits through which the lava once flowed. Tubes near the surface sometimes collapse as a result of meteor impacts or seismic events. This creates windows or skylights, revealing a hidden world within.
Over the course of billions of years, both high and low sections of the Moon have been pelted by asteroids and meteorites. Without an atmosphere like on Earth, these impactors do not burn up or break apart which causes major damage to the surface. The pieces of rock and dust that are scattered after an impact are known as the regolith, and over time this material has covered the entire surface of the Moon in a layer of loose sediments.
Some of this regolith has even made its way to Earth. These are lunar meteorites, pieces of the Moon that were ejected into space during a large impact and later fell to Earth. This specimen is a handcrafted “moon” composed of fine-grained dust extracted from one such lunar meteorite, NWA 5000.
One of the largest lunar meteorites, NWA 5000 is a gabbroic rock typical of highlands origin with evidence of impact melt. Argon isotopes indicate the mass crystalized after a large impact 3.2 billion years ago, then experienced a second impact just 500 million years ago which ejected it into space, sending it on a relatively quick trip to Earth.
📸 An artist's depiction of a planetoid impact, like the one that may have made our moon (Source: NASA)
A Moon Sized Explosion
Many theories have been posited as to the formation of Earth’s Moon. Natural satellites often occur when small bodies are caught in the gravitational field of a planet. Our moon, however, is quite a massive lunar body, relative to Earth. This complicates the theory that Earth was able to catch the Moon. After lunar samples had been collected by the Apollo mission revealing the presence of igneous rocks, a new theory was suggested that states a giant impactor struck the Earth early in its formation.
This impacting body has been named Theia after the mother of the Moon in Greek myth and is estimated to be roughly the size of Mars. This event threw a disk of debris into orbit around the Earth where it consolidated into a molten satellite. Over time, the lava cooled and the Moon as we know it today was formed.
Front of the Specimen Card
Back of the Specimen Card
Further Reading
Connolly Jr, Harold C. et al. “The Meteoritical Bulletin, No. 93, 2008 March.” Meteoritics & Planetary Science 43.3 (2008): 571–632. Web.
Grange, M. L., M. D. Norman, and V. Assis Fernandes. "Clues to the Origin of Gabbroic Lunar Meteorite Northwest Africa 5000." Lunar and Planetary Science Conference. Vol. 47. 2016.
Riccioli, Giovanni Battista. "Almagestum novum", Bologna, 1651.
Wood, Charles Arthur, and Maurice JS Collins. 21st century atlas of the Moon. West Virginia University Press, 2013.
Joy, Katherine H. Studies in Lunar Geology and Geochemistry using Sample Analysis and Remote Sensing Measurements, University of London, University College London (United Kingdom), Ann Arbor, 2007.
Halliday, Alex. “Terrestrial accretion rates and the origin of the Moon.” Earth and Planetary Science Letters, Vol 176, no. 1, 2000, pp. 17-30.