Introduction
Background
Meteorites, Meteors, meteoroids or as we call it, shooting stars are all terms that we’ve heard and often used interchangeably. We love to watch the bright light streaks on the night sky travelling at a remarkable speed, you would miss it in the blink of an eye. People love to search for these shooting stars and make a wish, but they seldom learn what these are and which term to use to describe them. According to NASA, Meteoroids are small, rocky objects that could be a fragment of an asteroid, comet or a planet. These objects stay in space. When a meteoroid enters the earths atmosphere, it becomes a meteor. That is what we usually call a shooting star. They enter our atmosphere at high speed and start to burn up. Some meteors survive the trip from space through the atmosphere and reach the ground, those meteors are called meteorites (NASA, 2024).
According to K.S. Wisniewski et al, about 48.5 tons or 44,000 kilograms of meteorite particles falls on earth each day (Wisniewski, Brown, & Moser, 2024). Most of these fragments will vaporize by the time they reach the ground. Any meteors big enough will survive and make impact with the earth.
History of Meteor Sightings
Until the early 19th century, meteors were thought to be atmospheric phenomenon, hence the word Meteor which derives from the Greek work meteoron, meaning something in the heaven or atmospheric phenomena. The first record of scientists starting to consider cosmic connections was in 1807 when Yale professor Benjamin Silliman investigated a meteorite which fell in Weston Connecticut. However, more serious attention to meteors were given after the meteor storm in the USA in November 1833 (Littmann & Suomela, 2014).
The American astronomer Denison Olmstead studied the meteor storm extensively and concluded that it had originated from space. Since then, people have been observing and analyzing meteors and their patterns. Meteor showers are when more than one fragment of meteoroids enter the earth’s atmosphere at a similar time. Meteor showers can happen during the daytime as well but because of the sunlight we can hardly see them. But during the night time, meteor showers can be an absolute spectacle. Meteor showers are named after the constellation from where the showers appears to be coming from. For example, the famous Perseid meteor shower seems to be coming from the Perseus constellation.
Composition of Meteorites
According to Kring, there are three main types of meteorites; Iron, Stone and Stony-irons (Kring, 1998). Iron meteorites are primarily composed of iron and nickel. Stone meteorites are composed of silicate minerals. Stony-iron meteorites are composed of a combination of silicate minerals and nickel-iron alloy.
Iron meteorites are thought to be formed in the cores of asteroids in the asteroid belt. When asteroids collide with each other, fragments break off from asteroids and some of these fragments might find their way towards the earth. Some iron meteorites contain Widmanstätten patterns, which are unique crystallin structures formed as the meteorite cooled.
Stoney meteorites or simply stones are similar to the rocks found on earth. They are further divided into two categories; Chondrites and Achondrites. Chondrites are the most common type of stony meteorites containing small round structures called chondrules. Chondrules are believed to have formed in the early stages of the formation of the solar system. Therefore, these meteorites contain valuable information about the formation of the solar system and the materials present during that stage. Achondrites are small stony meteorites that do not contain chondrules. These are believed to have originated from comets, asteroid or moons.
Stony-iron meteorites as the name suggests is a combination of the above two. They are believed to originate from the boundary region between a planets mantle and core, and they represent a very unique class of meteorites making up about 1% of all the known meteorite falls. Stony-iron meteorites are divided into two categories; pallasites and mesosiderites.
Pallasites are visually stunning and highly sought after by collectors and researcher due to its striking intergrowth of olivine crystals and metallic matrix.
Mesosiderites are much rarer than pallasites. They have a heterogeneous appearance with metal veins and silicate clasts mixed together.
Impact of Meteorites on Earth
The impact of meteorites is a fascinating topic, which takes us all the way to the formation of the earth. Massive impact events in the very early days of the earth’s formation are believed to have led to the formation of the moon, altered the earth’s spin, tilt and orbit, and brought water to the earth as it was formed (berkeley, 2024). It is now widely believed that meteorites had a big role to play in the formation of life on earth (Osinski, Cockell, & Pontefract, 2020).
G. R. Osinski in his 2021 article outlines that the impact of meteorites can be both good and bad. Many of us have heard of the bad outcomes of meteorites, especially the one that wiped out dinosaurs from the face of the earth (Osinski G. , 2021).
Around 66 million years ago, this famous extinction event wiped out approximately two-thirds of Earth’s species. In the early 1990s, scientists discovered the impact crater responsible for this catastrophe which was the 200 km-wide Chicxulub structure buried beneath nearly a kilometer of sediment near the Yucatán Peninsula, Mexico. Research over the decades has shown that the Chicxulub impact triggered massive tsunamis and earthquakes, launched vast amounts of dust and debris into the air, ignited global wildfires, and released significant sulfur aerosols into the atmosphere. These combined effects led to a dramatic drop in global temperatures by about 15°C, creating conditions similar to a nuclear winter. Such large-scale meteorite impacts have devastating global consequences, and if a similar event were to occur in the future, it could bring about the collapse of civilization.
The impact of meteorites is not all bad. Meteorites have played a crucial role in shaping Earth and life itself. They delivered essential elements like water, amino acids, and phosphorus, possibly aiding the origin of life. Also, studying meteorites provides insights into planetary history and space exploration, while asteroid mining could offer future resources for deep-space missions.
Importance of Analyzing Meteorite Landing Data
Coming back to the task at hand, the aim of this project is to analyze the past data of meteorite landings on earth. The importance of analyzing past meteorite data is crucial due to a few reasons,
Understanding the history of the solar system – as discussed earlier, the chemical composition of certain meteorites can offer clues to the formation of the solar system and the materials present at the time.
Impact studies – by analyzing past data, scientist can make predictions to future asteroid impacts on earth and identify any large scale threats.
Clues about early life – as it is widely accepted that the building blocks of life came to earth with meteorites, analyzing the data can offer clues into the past of our very own origins.
There are many other benefits to analyzing meteorite data on earth. This area of study is very fascinating and dynamic with potential to expand to many other related studies.
The Dataset
The aim of this study is to analyze previous meteorite landing data by NASA. The author has downloaded the dataset from NASA public data portal at https://data.nasa.gov/Space-Science/Meteorite-Landings/gh4g-9sfh/about_data. The dataset consists of 34,513 meteorites and includes the following fields,
Name
Nametype – valid for meteorites and relict for objects that were once meteorites but are now highly altered by weathering on Earth
Class of meteorite
Mass in grams
Fall – whether it fell or found
Year
Latitude
Longitude
Geolocation
Tools
The following tools were used to analyze the data,
Jupyter Notebook
SQL – for querying the dataset
Python – for data preparation, analysis and visualization
SQLite