Aerial view of Arizona's Meteor Crater, a 180 meter deep, 1.2 kilometer diameter bowl-shaped impact crater in Northern Arizona. The crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite that was approximately 30 meters in diameter and struck at an approximate speed of 12-20 km/sec.
I think I found a meteorite. How can I tell for sure?
Meteorites are fragments of rock or metal that fall to Earth from space. They are very rare, but many people find unusual rocks or pieces of metal and wonder if they might have found a meteorite. The USGS doesn't verify meteorites, but they have several properties that help distinguish them from other rocks:
- Density: Meteorites are usually quite heavy for their size, since they contain metallic iron and dense minerals.
- Magnetic: Since most meteorites contain metallic iron, a magnet will often stick to them. For “stony” meteorites, a magnet might not stick, but if you hang the magnet by a string, it will be attracted.
- Unusual shape: iron-nickel meteorites are rarely rounded. Instead, they have an irregular shape with unusual pits like finger prints in their surface called “regmaglypts.”
- Fusion crust: stony meteorites typically have a thin crust on their surface where it melted as it passed through the atmosphere.
Meteorites do NOT have the following:
- Light-colored crystals: Quartz is a common, light-colored crystal in Earth’s crust, but it is not found on other bodies in the solar system.
- Bubbles: volcanic rocks or metallic slag on Earth often have bubbles or vesicles in them, but meteorites do not.
- Streak: if you scratch a meteorite on an unglazed ceramic surface, it should not leave a streak. A dense rock that leaves a black or red streak probably contains the iron minerals magnetite or hematite, respectively, neither of which are typically found in meteorites.
These tips for identifying a meteorite were adapted from a guide by the University of New Mexico Meteorite Museum.
Rocks and minerals--including potential meteorites--must be examined in person for proper identification. For suggestions on where to do that, see: Can you identify my rock or mineral?
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How can I tell if I have found an impact crater?
There are many natural processes other than impacts that can create circular features and depressions on the surface of the Earth. Examples include glaciation, volcanism, sinkholes, atolls, salt domes, intrusions, and hydrothermal explosions (to name just a few). Prehistoric mines and quarries are also sometimes mistaken for impact craters. Although the USGS has been involved in impact crater...
Can you identify my rock or mineral?
Rocks and minerals must be examined in person from all perspectives for accurate identification; they are extremely difficult to identify through photographs. You will get the best results by taking your rock or mineral to a local source where it can be handled and examined closely. Possibilities include: Your state geological survey A natural science museum A college or university with a geology...
What is the difference between a rock and a mineral?
A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. Common minerals include quartz, feldspar, mica, amphibole, olivine, and calcite. A rock is an aggregate of one or more minerals, or a body of undifferentiated mineral matter. Common rocks include granite, basalt...
Aerial view of Arizona's Meteor Crater, a 180 meter deep, 1.2 kilometer diameter bowl-shaped impact crater in Northern Arizona. The crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite that was approximately 30 meters in diameter and struck at an approximate speed of 12-20 km/sec.
Meteor Crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite, ~30 m in diameter, which struck at an approximate speed of 12-20 km/sec.
Meteor Crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite, ~30 m in diameter, which struck at an approximate speed of 12-20 km/sec.
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Related
How can I tell if I have found an impact crater?
There are many natural processes other than impacts that can create circular features and depressions on the surface of the Earth. Examples include glaciation, volcanism, sinkholes, atolls, salt domes, intrusions, and hydrothermal explosions (to name just a few). Prehistoric mines and quarries are also sometimes mistaken for impact craters. Although the USGS has been involved in impact crater...
Can you identify my rock or mineral?
Rocks and minerals must be examined in person from all perspectives for accurate identification; they are extremely difficult to identify through photographs. You will get the best results by taking your rock or mineral to a local source where it can be handled and examined closely. Possibilities include: Your state geological survey A natural science museum A college or university with a geology...
What is the difference between a rock and a mineral?
A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. Common minerals include quartz, feldspar, mica, amphibole, olivine, and calcite. A rock is an aggregate of one or more minerals, or a body of undifferentiated mineral matter. Common rocks include granite, basalt...
Aerial view of Arizona's Meteor Crater, a 180 meter deep, 1.2 kilometer diameter bowl-shaped impact crater in Northern Arizona. The crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite that was approximately 30 meters in diameter and struck at an approximate speed of 12-20 km/sec.
Aerial view of Arizona's Meteor Crater, a 180 meter deep, 1.2 kilometer diameter bowl-shaped impact crater in Northern Arizona. The crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite that was approximately 30 meters in diameter and struck at an approximate speed of 12-20 km/sec.
Meteor Crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite, ~30 m in diameter, which struck at an approximate speed of 12-20 km/sec.
Meteor Crater formed approximately 50,000 years ago by the impact of a 100,000-ton iron-nickel meteorite, ~30 m in diameter, which struck at an approximate speed of 12-20 km/sec.