This article needs to be updated.(May 2015) |
The Managua event was an explosion that was widely reported as a possible meteorite fall on 6 September 2014 in Managua, Nicaragua, near the Augusto C. Sandino International Airport runway. Its actual cause remains undetermined.
Witnesses in Managua reported hearing a blast and seeing a dust cloud that smelled like something had burned, on the night of 6 September. [1] A crater 12 m (39 ft) wide and 5 m (16 ft) deep was found in the vicinity of the Nicaraguan Air Force base zone of the airport. Initial reports claimed that two seismic waves were detected associated with the event, [1] but no such events are reported on the Nicaraguan Seismic Network website. [2]
The Nicaraguan Vice-Minister of the Exterior, Orlando Zamora, sent a letter on 9 September 2014 to the US Ambassador to Nicaragua, requesting the "arrangement of cooperation" with USGS and inviting a "meteor expert" to visit the crater site to coordinate efforts of the scientific community investigating the event. [3] In the letter, Mr. Zamora also stated that "seismic and acoustic waves were recorded by at least 24 seismic stations near the city of Managua." [3]
In media press conference interviews on 7 September 2014, local geophysical scientists who visited the site described finding "tiny mirror-like particles" in the volcanic ash soil along the walls of the crater (exact coordinates = 12°08′38.96″N086°11′03.04″W / 12.1441556°N 86.1841778°W ) and noted ejecta "extending off toward the east-north-east". [4] The scientists indicated they "would need to study the site further" and were "seeking to collaborate with experts in other countries". [5]
Although the earliest news reports made no claim of a meteor, [6] many news sources reported speculations that a meteor had created the crater and the blast. [7] [8] [9] Many of the speculations proposed an association between the Managua event and the close Earth flyby of the asteroid 2014 RC, which happened late on 7 September. [10] Such an association is not possible: 2014 RC was about 40,000 km (25,000 mi) from Earth at its closest approach, over New Zealand; nothing on the same trajectory could have entered the Earth's atmosphere over Nicaragua; [11] [12] and the crater in Managua was reported 13 hours prior to 2014 RC's closest approach.
On Sunday 7 September 2014, at the first press conference of the inter-institutional commission formed to study the event, Dr. Wilfried Strauch, a German seismic scientist working at the Nicaraguan Seismic Network (INETER) [2] in Managua, described impulses correlated to the event timing, [13] and referred to heliplot seismograph charts with pulses at 05:04:45 UTC (23:04:45 Local Time) at the Managua airport seismic station (MGAN BLZ NU), [14] another at a more distant station around 05:05:47 UTC [15] and also indicated that there were records of 18 other stations in the network that were being examined. [13]
At the second INETER commission press conference on Tuesday 9 September 2014, [16] the team of local scientists said that "bits of compacted unusual debris found in the bottom of the crater" were being sent off to labs for analysis, and access to the site was controlled to prevent contamination of evidence pending examination by visiting scientists specializing in this field. [16] Some physical debris samples taken at the crater by the scientific team were sent to the National Autonomous University of Mexico (UNAM). Additionally, they announced that "USGS and NASA have been contacted regarding possible advice" on the study. [17] One of the scientists on the commission, Dr. José Milán, said "an awning would be set up to protect the crater area from possible rain showers" and another scan of the area for unusual ejecta debris on the ground or "any material embedded in surrounding trees" was being performed. [18] According to Dr. Milán, the research work at the site also included 3d imaging of the crater and surrounding area, Ground Penetrating Radar (GPR), and a magnetometer grid study. [18] No results of the studies were announced.
No eyewitnesses, ground-based cameras, or satellite operators reported seeing a meteor (bolide), and no meteorites have been recovered. [19] To create a crater of that size by meteorite impact would have required a bolide brighter than the full Moon. [20] This indicates that the crater was most likely not produced by a meteorite fall. [21] [22]
Other potential explanations for the crater's formation include ground slumping, [12] [ better source needed ] a sinkhole, [12] [ better source needed ] excavation, or a ground-based explosive detonation [12] - either that which caused the blast reported on the night of 6 September 2014 or one that occurred before that time.
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples "bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater.
The Tunguska event was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate, Russia, on the morning of 30 June 1908. The explosion over the sparsely populated East Siberian taiga flattened an estimated 80 million trees over an area of 2,150 km2 (830 sq mi) of forest, and eyewitness reports suggest that at least three people may have died in the event. The explosion is generally attributed to a meteor air burst: the atmospheric explosion of a stony asteroid about 50–60 metres in size. The asteroid approached from the east-south-east, and probably with a relatively high speed of about 27 km/s (60,000 mph). Though it is classified as an impact event, the object is thought to have exploded at an altitude of 5 to 10 kilometres rather than having hit the surface of the Earth, leaving no impact crater.
Meteor Crater or Barringer Crater is a meteorite impact crater about 37 mi (60 km) east of Flagstaff and 18 mi (29 km) west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are officially called the Canyon Diablo Meteorite, after the adjacent Canyon Diablo.
A meteoroid is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than meteoroids are classified as micrometeoroids or space dust. Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars.
An impact event is a collision between astronomical objects causing measurable effects. Impact events have physical consequences and have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and biospheric consequences, though atmospheres mitigate many surface impacts through atmospheric entry. Impact craters and structures are dominant landforms on many of the Solar System's solid objects and present the strongest empirical evidence for their frequency and scale.
The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore, but the crater is named after the onshore community of Chicxulub Pueblo. It was formed slightly over 66 million years ago when a large asteroid, about ten kilometers in diameter, struck Earth. The crater is estimated to be 180 kilometers in diameter and 20 kilometers in depth. It is the second largest confirmed impact structure on Earth, and the only one whose peak ring is intact and directly accessible for scientific research.
The term Spaceguard loosely refers to a number of efforts to discover, catalogue, and study near-Earth objects (NEO), especially those that may impact Earth.
The geology of solar terrestrial planets mainly deals with the geological aspects of the four terrestrial planets of the Solar System – Mercury, Venus, Earth, and Mars – and one terrestrial dwarf planet: Ceres. Earth is the only terrestrial planet known to have an active hydrosphere.
The Carancas impact event refers to the fall of the Carancas chondritic meteorite on September 15, 2007, near the village of Carancas in Peru, close to the Bolivian border and Lake Titicaca. The impact created a small crater in the clay soil and scorched earth around its location. A local official, Marco Limache, said that "boiling water started coming out of the crater, and particles of rock and cinders were found nearby", as "fetid, noxious" gases spewed from the crater. Surface impact occurred above 3,800 metres (12,500 ft).
2008 TC3 (Catalina Sky Survey temporary designation 8TA9D69) was an 80-tonne (80-long-ton; 90-short-ton), 4.1-meter (13 ft) diameter asteroid that entered Earth's atmosphere on October 7, 2008. It exploded at an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. Some 600 meteorites, weighing a total of 10.5 kilograms (23.1 lb), were recovered; many of these belonged to a rare type known as ureilites, which contain, among other minerals, nanodiamonds.
Mojave is a 58 km diameter impact crater in the Oxia Palus quadrangle of Mars, located at 7.5° N and 33.0° W. It was named after the town of Mojave in southern California, U.S.
A meteor air burst is a type of air burst in which a meteoroid explodes after entering a planetary body's atmosphere. This fate leads them to be called fireballs or bolides, with the brightest air bursts known as superbolides. Such meteoroids were originally asteroids and comets of a few to several tens of meters in diameter. This separates them from the much smaller and far more common "shooting stars", that usually burn up quickly upon atmospheric entry.
Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures is a book written by Bevan M. French of the Smithsonian Institution. It is a comprehensive technical reference on the science of impact craters. It was published in 1998 by the Lunar and Planetary Institute (LPI), which is part of the Universities Space Research Association (USRA). It was originally available in hard copy from LPI, but is now only available as a portable document format (PDF) e-book free download.
The Chelyabinsk meteor was a superbolide that entered Earth's atmosphere over the southern Ural region in Russia on 15 February 2013 at about 09:20 YEKT. It was caused by an approximately 18 m (59 ft) diameter, 9,100-tonne (10,000-short-ton) near-Earth asteroid that entered the atmosphere at a shallow 18.3 ± 0.4 degree angle with a speed relative to Earth of 19.16 ± 0.15 kilometres per second. The light from the meteor was briefly brighter than the Sun, visible as far as 100 km (60 mi) away. It was observed in a wide area of the region and in neighbouring republics. Some eyewitnesses also reported feeling intense heat from the fireball.
2014 RC is a sub-kilometer near-Earth object and Apollo asteroid. The exceptionally fast rotator passed within 0.000267 AU (39,900 km; 24,800 mi) (0.1 lunar distances) of Earth on 7 September 2014. The asteroid is approximately the diameter of the Chelyabinsk meteor, and passed almost as close to Earth as 367943 Duende (2012 DA14) did in 2013.
2018 LA, also known as ZLAF9B2, was a small Apollo near-Earth asteroid 2.6–3.8 m (9–12 ft) in mean diameter that impacted the atmosphere with small fragments reaching the Earth at roughly 16:44 UTC on 2 June 2018 near the border of Botswana and South Africa. It had been discovered only 8 hours earlier by the Mount Lemmon Survey, Arizona and based on 1+1⁄2 hours of observations, was calculated to have a roughly 85% chance of impact likely somewhere between Australia and Madagascar.
In modern times, numerous impact events on Mars have been detected. Although most have been inferred from the appearance of new impact craters on the planet, some have corresponded to marsquakes felt by the InSight lander. To date, no impacting meteors have been directly observed as a fireball or discovered in space before impact.