Falling Meteor Creates Loud Booms in Indonesia; Geologist Analysis

[00:00:00]On Saturday evening, at approximately 9:23 pm to  9:24 pm local time, as many as 5 million people may have heard a loud series of booms that sounded  like explosions. This occurred on the island of Java, with reports coming in primarily from  Cirebon Regency. Thankfully, these booms were not due to a regional volcano erupting, but rather  had an extraterrestrial origin. As, a bright white streak with a faint blue tint streaked across  the sky at that time, being seen as far away as Yogyakarta. This represented a fireball as a  meteor entered the Earth's atmosphere, traveling at presumably high speeds of 17 kilometers per  second or 38,000 miles per hour. At around 120 kilometers altitude, the air began compressing  to an extreme level in front of the southeastward moving meteor, heating that air to such a degree  that it began also vaporizing the meteor. Meaning, that that the bright light you see from a meteor  isn't it burning like a piece of wood above a campfire, but rather the rock exterior quickly  turning into plasma, and this emits light.

[00:01:14]In the case of the meteor seen in the sky of  Indonesia on July 11th, it had a primarily white color with a light blue hint. This color  is important, as remember, as it can help us determine a meteor's composition, with this  chart roughly correlating to most possibilities.

[00:01:33]I personally interpret that this coloration was  caused by a small probably less than 70 centimeter wide meteor that had a primarily iron-nickel  composition. Probably, an octahedrite, although an ataxite or hexahedrite remains possible. While  it is technically possible that some fragments of this meteor impacted the ground, I personally  consider this highly unlikely given that its low peak brightness all things considered and low  atmospheric angle made it highly likely that it completely disintegrated. While there are no  official values that have been released regarding the brightness of this interesting meteor, it  almost certainly was brighter than -4, so it would be classified as a fireball, and possibly  also a bolide; I personally suspect the true magnitude was around -14.2. Thus, if no parts of  it did impact the ground, that is why it would be a meteor and not a meteorite. As for the booming  and explosions sounds people heard, those were in fact caused by sonic booms from the meteor moving  at least 50 times faster than the speed of sound.

[00:02:47]Such events may be startling, but honestly aren't  all that unexpected or rare, at least if we are talking on a global scale each year. Specifically,  several hundred thousand meteors that could be classified as fireballs enter Earth's atmosphere  every year, and 5,000 of these each year could be classified as bolides. This means that within  100 kilometers of the island of Java, about 2 to 3 bolides can be expected to occur every year. Iron-nickel meteorites are somewhat uncommon, representing only a little more than 4% of  all discovered meteorite falls that have been recovered. Such meteorites originated in the  early solar system around 4.57 billion years ago, originating at the core of large planetesimals  that were more than 20 kilometers wide.

[00:03:40]Such dimensions marked the minimum required for  a form of planetary differentiation to occur, causing denser materials to migrate towards the  core and lighter materials to migrate upwards to the crust. Many of these planetesimals  were later destroyed by major collisions, causing fragments of their core to remain  in space and occasionally then enter Earth's atmosphere as iron-nickel meteorites. And  that is the likely story of the meteor that presumably completely disintegrated at more  than 40 kilometers altitude in the atmosphere.

[00:04:17]I hope that you found this video  interesting. I would like to give a special thanks to my new YouTube channel  member JackMellor498 for supporting my work!