A meteorite crashed into an engineering college in Vellore district on Saturday, causing an explosion that killed one man and injured three others, the Tamil Nadu government said on Sunday.Scientists, however, said it wasn't clear how the government concluded that a meteorite strike caused the blast. There has been no established death due to a meteorite hit in recorded history, they said.If a meteorite indeed caused the death, bus driver Kamaraj will be the first person ever to have died in a meteorite strike. Saturday's blast also injured two gardeners and a student.“You have a better chance of getting hit by a tornado and a bolt of lightning and a hurricane all at the same time,“ is how astronomer and author of the book, Falling Stars: A Guide to Meteors & Meteorites Michael Reynolds describes the likelihood of such an event in a National Geographic report.Regardless of the scepticism of experts, chief minister J Jayalalithaa on Sunday said the government would pay compensation of Rs 1 lakh to Kamaraj's family .The three people injured in the explosion will receive Rs 25,000 each, she said.Witnesses said the blast left a crater 5ft deep and 2ft wide. Policemen recovered a black, pockmarked stone weighing 11g from the blast site.A police officer said the department would consult experts from the Indian Institute of Astrophysics in Bengaluru and ask them for a detailed analysis of the stone to ascertain whether it is debris from a meteorite. A team of experts from the institute will visit the site on February 8.A bomb squad from Chennai took debris samples on Sunday for analysis at Regional Forensic Science Laboratory in Mylapore. Police said preliminary investigation by police forensics experts ruled out the possibility that explosives caused the blast.“We did not find any trace of explosive substances, so we ruled out the possibility that explosives caused the blast,“ an investigating officer said. “We will wait for a final autopsy report on the body of driver Kamaraj and the report from the forensic lab to confirm what triggered the explosion.“The blast, which took place during class hours on Saturday when students, teachers and other staff were within the college's main building, shattered several windowpanes and damaged the windscreens of buses parked nearby . Police said Kamaraj went to wash his face at a tap near a water tank in the parking lot of the college when the explosion occurred around noon on Saturday . Thick smoke engulfed the area, witnesses said. A student, Santhosh, and two gardeners, Sasi and Murali, were injured. The blast deafened Santhosh, although doctors could not immediately say if the condition would be permanent.The first person in history that a meteorite is confirmed to have hit was American Ann Hodges, 'National Geographic' reported. A softball-size hunk of black rock broke through the ceiling of her house in Sylacauga, Alabama, in November 1954 and hit her in the thigh, leaving a pineapple-shaped bruise. Scientists closely watch space bodies that come to earth and predict in advance when a meteor large enough to stay intact after burning up in the atmosphere is going to hit the planet.“Organizations like International Meteor Organization have already put out the calendar for 2016 -for the days we can expect meteor showers and if there are any chances of them hitting earth. These occurrences are catalogued for the benefit of stargazers,“ said Isro Mars Orbiter Mission project director V Adimurthy.“They even predict the time of the meteor showers and are almost never wrong,“ he said. “The last meteor shower was on January 3 and the next one is between April 22 and 23. There is nothing for February." ||||| A 40-year-old Indian man may have become the first person known to be killed by a meteorite falling from space. The presumed meteorite left a four-feet deep crater after falling into the campus of a private college in the state of Tamil Nadu at 12.30 p.m. on Saturday. 
 
 The powerful explosion also injured three gardeners and shattered window panes, but the students who were attending classes at the time were safe. On Sunday, Tamil Nadu chief minister J Jayalalithaa said that the death of the man named Kamaraj, who worked as driver working in the Bharathdasan Engineering College Campus in Vellore district, had been caused by a meteorite. 
 
 However, some scientists are skeptical of the claim. 
 
 @BadAstronomer do you have an opinion on the alleged TamilNadu meteorite fatality? My skeptical spideysense is tingling — Jonathan McDowell (@planet4589) February 8, 2016 
 
 @planet4589 @BadAstronomer small meteorites do not create blast wave upon impact. Damage reported very local, undeep crater. Does not ad up — Dr Marco Langbroek (@Marco_Langbroek) February 8, 2016 
 
 @Marco_Langbroek @planet4589 @BadAstronomer I was sent picture of a minute meteorite recovered from the alleged impact site: makes no sense. — Daniel Fischer (@cosmos4u) February 8, 2016 
 
 While officials initially investigated it as a possible terror attack, they were not able to find any explosives. According to some reports, a similar incident had occurred in a village nearby last week. 
 
 Local scientists still have to confirm that a meteorite was responsible for the death. 
 
 Piece of a meteorite found at a private engineering college in Vellore. One person was dead in the explosion. pic.twitter.com/TON5qzIw7N — J Sam Daniel Stalin (@jsamdaniel) February 7, 2016 
 
 Windows shattered due to Meteor impact at Naatraampalli, Vellore. Just like russian meteor impact . pic.twitter.com/5ioJdNBV1c — Prashanth (@itisprashanth) February 7, 2016 
 
 There have been no recorded deaths by meteorites so far. According to a study by astronomer Alan Harris, the odds of being killed by a meteorite are 1 in 700,000. However, this risk increases as the size of the meteorite gets bigger. For instance, in 2013, a meteorite hit the Russian city of Chelyabinsk injuring over 1,000 people and damaging buildings. ||||| Asteroids, meteors, and meteorites … It might be fair to say these rocks from space inspire both wonder and fear among us Earthlings. But knowing a bit more about each of them and how they differ may eliminate some potential misgivings. While all these rocks originate from space, they have different names depending their location — i.e. whether they are hurtling through space or hurtling through the atmosphere and impacting Earth’s surface. 
 
 In simplest terms here are the definitions: 
 
 Asteroid: a large rocky body in space, in orbit around the Sun. 
 
 Meteoroid: much smaller rocks or particles in orbit around the Sun. 
 
 Meteor: If a meteoroid enters the Earth’s atmosphere and vaporizes, it becomes a meteor, which is often called a shooting star. 
 
 Meteorite: If a small asteroid or large meteoroid survives its fiery passage through the Earth’s atmosphere and lands on Earth’s surface, it is then called a meteorite. 
 
 Another related term is bolide, which is a very bright meteor that often explodes in the atmosphere. This can also be called a fireball. 
 
 Let’s look at each in more detail: 
 
 
 
 Asteroids 
 
 
 
 Asteroids are found mainly in the asteroid belt, between Mars and Jupiter. Sometimes their orbits get perturbed or altered and some asteroids end up coming closer to the Sun, and therefore closer to Earth. In addition to the asteroid belt, however, there have been recent discussions among astronomers about the potential existence of large number asteroids in the Kuiper Belt and Oort Cloud. You can read a paper about this concept here, and a good article discussing the topic here. 
 
 Asteroids are sometimes referred to as minor planets or planetoids, but in general, they are rocky bodies that do not have an atmosphere. However, a few have their own moons. Our Solar System contains millions of asteroids, many of which are thought to be the shattered remnants of planetesimals – bodies within the young Sun’s solar nebula that never grew large enough to become planets. 
 
 The size of what classifies as an asteroid is not extremely well defined, as an asteroid can range from a few meters wide – like a boulder — to objects that are hundreds of kilometers in diameter. The largest asteroid is asteroid Ceres at about 952 km (592 miles) in diameter, and Ceres is so large that it is also categorized as a dwarf planet. 
 
 Most asteroids are made of rock, but as we explore and learn more about them we know that some are composed of metal, mostly nickel and iron. According to NASA, a small portion of the asteroid population may be burned-out comets whose ices have evaporated away and been blown off into space. Recently, astronomers have discovered some asteroids that mimic comets in that gas and dust are emanating from them, and as we mentioned earlier, there appears to be a large number of bodies with asteroid-like compositions but comet-like orbits. 
 
 How Often Do Asteroids Hit Earth? 
 
 While we know that some asteroids pass very close to Earth’s orbit around the Sun, we’ve been lucky in the history of humanity that we haven’t had a large asteroid hit Earth in the past several thousand years. It wasn’t until satellite imagery of Earth became widely available that scientists were able to see evidence of past asteroid impacts. 
 
 One of the more famous impact craters on Earth is Meteor Crater in Arizona in the US, which was made by an impact about 50,000 years ago. But there are about 175 known impact around the world – a few are quite large, like Vredefort Crater in South Africa which has an estimated radius of 190 kilometers (118 miles), making it the world’s largest known impact structure on Earth. Another notable impact site is off the coast of the Yucatan Peninsula in Mexico, and is believed to be a record of the event that led to the extinction of the dinosaurs 65 million years ago. You can see images of some of the most impressive Earth impact craters here. 
 
 These days, asteroid impacts are less of a threat. NASA estimates that about once a year an automobile-sized asteroid enters Earth’s atmosphere, creates an impressive fireball and disintegrates before ever reaching the surface. Studies of Earth’s history indicate that about once every 5,000 years or so on average an object the size of a football field hits Earth and causes significant damage. Once every few million years on average an object large enough to cause regional or global disaster impacts Earth. You can find more information about the frequency of impacts in this article from NASA. 
 
 
 
 Meteors, Meteoroids and Bolides 
 
 Space debris smaller than an asteroid are called meteoroids. A meteoroid is a piece of interplanetary matter that is smaller than an asteroid and frequently are only millimeters in size. Most meteoroids that enter the Earth’s atmosphere are so small that they vaporize completely and never reach the planet’s surface. When they burn up during their descent, they create a beautiful trail of light known as a meteor, sometimes called a shooting star. 
 
 Mostly these are harmless, but larger meteors that explode in the atmosphere – sometimes called bolides — can create shockwaves, which can cause problems. In February 2013 a meteor that exploded over Chelyabinsk, Russia shattered windows with its air blast. This meteoroid or bolide was estimated to be 18 meters (59 feet) in diameter. In 1908, a rocky meteoroid less than 100 meters in diameter is believed to have entered the atmosphere over the Tunguska region of Siberia in 1908 and the resulting shockwave knocked down trees for hundreds of square kilometers 
 
 How often is Earth hit by meteroids? 
 
 Because of the Chelyabinsk meteor in 2013, astronomers have acquired more information about the frequency of larger meteors that hit Earth, and there is now a growing consensus that the Earth gets hit by bigger space rocks more often than we previously thought. You can read more about that concept here. 
 
 This video from the B612 Foundation shows a visualization of the location of 26 space rocks that hit Earth between 2000 and 2013, each releasing energy equivalent to some of our most powerful nuclear weapons. The B612 foundation says that a Hiroshima-scale asteroid explosion happens in our atmosphere on average once a year, but many are not detected because they explode high in the atmosphere, or because most of the Earth’s surface is water and even a large percentage of land is fairly uninhabited by humans. 
 
 Estimates vary of how much cosmic dust and meteors enter Earth’s atmosphere each day, but range anywhere from 5 to 300 metric tons. Satellite observations suggest that 100-300 metric tons of cosmic dust enter the atmosphere each day. This figure comes from the rate of accumulation in polar ice cores and deep-sea sediments of rare elements linked to cosmic dust, such as iridium and osmium. 
 
 But other measurements – which includes meteor radar observations, laser observations and measurements by high altitude aircraft — indicate that the input could be as low as 5 metric ton per day. Read more about this here. 
 
 For a documented list of bolide events, you can check out this page from JPL. 
 
 Meteorite 
 
 
 
 If any part of a meteoroid survives the fall through the atmosphere and lands on Earth, it is called a meteorite. Although the vast majority of meteorites are very small, their size can range from about a fraction of a gram (the size of a pebble) to 100 kilograms (220 lbs) or more (the size of a huge, life-destroying boulder). Meteorites smaller than 2mm are classified as micrometeorites. 
 
 Meteorites have traditionally been divided into three broad categories, depending on their structure, chemical and isotopic composition and mineralogy. Stony meteorites are rocks, mainly composed of silicate minerals; iron meteorites that are largely composed of metallic iron-nickel; and, stony-iron meteorites that contain large amounts of both metallic and rocky material. 
 
 Meteorites have also been found on the Moon and Mars and conversely, scientists have traced the origination of the meteorites found here on Earth to four other bodies: the Moon, Mars, the asteroid 4 Vesta, and the comet Wild 2. Meteorites are the source of a great deal of the knowledge that we have have about the composition of other celestial bodies. 
 
 How Often Do Meteorites Hit Earth? 
 
 According to the Planetary Science Institute, it is estimated that probably 500 meteorites reach the surface of the Earth each year, but less than 10 are recovered. This is because most fall into water (oceans, seas or lakes) or land in remote areas of the Earth that are not accessible, or are just not seen to fall. 
 
 You can read more about meteorites that were found from the Chelyabinsk meteor here. 
 
 Summary 
 
 In short, the difference between asteroids and meteors all comes down to a question of location. Asteroids are always found in space. Once it enters an atmosphere, it becomes a meteor, and then a meteorite after it hits the ground. Each are made of the same basic materials – minerals and rock – and each originated in space. The main difference is where they are when they are being observed. 
 
 We have many great articles on the subject of asteroids and meteorites here at Universe Today, such as this general information article on asteroids, this article and infographic about the difference between comets, asteroids and meteors, and these articles that deal with Ceres and Vesta. And here are some recent articles about the Chelyabinsk meteor that landed in Russia, as well as a 2 billion-year old Martian meteorite that contains evidence of water on Mars. 
 
 There is some good information on a NASA page as well as some great information here on Universe Today and Astronomy Cast. 
 
 Sources: 
 
 JPL’s Near Earth Asteroid Office 
 
 Planetary Science Institute 
 
 NASA: Asteroids 
 
 NASA: Meteors 
 
 By Nancy Atkinson - 
 
 Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is the author of the new book "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos." She is also a NASA/JPL Solar System Ambassador. 
 
 4 vesta, asteroid, asteroid belt, ceres, Jupiter, Mars, meteor, meteorite, meteoroid, planetoid, the moon ||||| A man was killed and three others were injured Saturday in what authorities said was a meteorite strike at a college campus in the southern Indian state of Tamil Nadu. 
 
 An unidentified object left a four-feet deep crater after falling near a cafeteria inside the Bharathidasan Engineering College campus at about 12.30 p.m. on Saturday, G. Baskar, principal of the college in Tamil Nadu’s Vellore district, said. 
 
 “There was a noise like a big explosion,” said Mr. Baskar. “It was an abnormal sound that could be heard till at least 3 kilometers [about 2 miles] away,” he added. 
 
 It would be the first time in modern history that a person has been killed by a meteorite. 
 
 The powerful explosion smashed the windows of classrooms and the windshields of vehicles parked in the vicinity. Students at the college were immediately sent home and classes were suspended until Wednesday. 
 
 Mr. Baskar described the tiny rock fragments observed at the site of the explosion on Saturday as “blue-ish black” in color. 
 
 V. Kamaraj, who operated a bus for the college, suffered severe injuries while he was walking close to the area where the object struck. He died Saturday. Three others, including two gardeners working inside the campus and a student at the college, were also injured during the incident. 
 
 J. Jayalalithaa, Tamil Nadu’s chief minister, said in a statement Sunday that Mr. Kamaraj died after a meteorite fell inside the college campus. She didn’t elaborate on what led authorities to believe the crater was caused by a meteorite. A spokesman for Ms. Jayalalithaa’s office couldn’t immediately be reached to comment. 
 
 A meteoroid is a small particle from an asteroid or comet that goes around the sun. When a meteoroid enters the Earth’s atmosphere it burns up, often seen as the light phenomenon known as a shooting star. A meteorite is a meteoroid that survives entry into the atmosphere and falls to Earth. 
 
 Sujan Sengupta, an associate professor at the Indian Institute of Astrophysics, said there was “extremely little possibility of a small meteorite falling to the ground” and killing someone. 
 
 “If a bigger asteroid enters the Earth’s atmosphere, it will disintegrate and travel in different directions and because most of the Earth’s surface is covered in water, it is most likely to fall into the ocean,” Mr. Sengupta said. 
 
 According to the U.S. National Aeronautics and Space Administration, there is no record “in modern times of any person being killed by a meteorite.” 
 
 “An individual’s chance of being killed by a meteorite is small, but the risk increases with the size of the impacting comet or asteroid,” NASA says on its website. A meteoroid larger than half a mile in diameter could have worldwide effects. If something smaller than that hits the Earth, it is likely to cause local damage. 
 
 The space agency’s “Near Earth Object Program” detects, tracks and characterizes potentially hazardous asteroids and comets that might approach Earth. As of Feb. 5, NASA says it has discovered 879 asteroids with a diameter of approximately a kilometer or larger. Experts say smaller asteroids and meteorites are harder, if not impossible, to track. 
 
 In 2013, a meteor explosion over Russia’s Ural Mountains left around 1,000 people injured, mostly by flying glass. Around 3,000 buildings were damaged. Russia’s Academy of Sciences said at the time that the meteor was several yards in diameter and weighed around 10 metric tons. 
 
 Ms. Jayalalithaa, the chief minister, announced compensation of 100,000 rupees ($1,473) for the family of the driver and 25,000 rupees to each of those injured. 
 
 Correction: A previous version of this post, in one instance, incorrectly said the incident took place on Sunday. It occurred on Saturday. 
 
 For breaking news, features and analysis from India, follow WSJ India on Facebook
– There's the slim chance of being hit by lightning, and then there's the almost nonexistent chance of being hit by a meteorite. A man in India, however, was apparently killed by the latter, which would likely make him the first person recorded killed by an object that fell from outer space, Mashable reports. V. Kamaraj, a 40-year-old bus driver for Bharathidasan Engineering College in Tamil Nadu, was reportedly walking on campus when the meteorite smashed down around 12:30pm Saturday, the Wall Street Journal reports; he suffered severe injuries and died, while two gardeners and a student were injured. "There was a noise like a big explosion," the college principal says. "It was an abnormal sound that could be heard … about 2 miles away." Students were sent home, and classes are nixed until Wednesday. NASA says there's no record "in modern times of any person being killed by a meteorite," and an astronomer pegged the odds of being killed by an asteroid (a meteorite is a piece of an asteroid that survives entry into Earth's atmosphere and lands) within one's lifetime as 1 in 700,000—a chance Discover notes is rare but still higher than getting killed by a terrorist (though the Discover article is from 2008). This particular meteorite was powerful enough to shatter window panes and car windshields, as well as leave a 4-foot-deep crater where it landed and what the principal describes as "blue-ish black" rock particles. The government has confirmed the deceased died from being hit by a meteorite, but some scientists are calling for further analysis of the rock, the Times of India notes. "You have a better chance of getting hit by a tornado and a bolt of lightning and a hurricane all at the same time," one astronomer says. (International Comet Quarterly lists "some interesting meteorite falls of the last two centuries," noting it was "possible" a man was killed in 1825.)