Rings of Earth

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The rings of Earth are a proposed set of planetary rings that may have at one point been present around Earth during the Ordovician period. These rings may have formed during the Ordovician impact spike approximately 466 million years ago. [1] [2] [3] They were first formally proposed by a team of scientists working with the Monash University in September 2024, and have been a subject of interest for several years prior to the study.

Contents

Background

The Ordovician Period was the geologic period and system that the Earth was in when the rings are believed to have formed. The Ordovician spanned from 485.4 million years ago to 443.8 million years ago. During this period, an event known as the Ordovician meteor event occurred, when a high level of L chondrite meteorites hit Earth. The meteorites may have been caused by a large parent body that was 93 miles (150 km) in diamater. [4]

History

Formation

The parent body that produced the L chondrite meteorites is believed to have passed Earth's Roche limit, leading to the body being torn apart and its debris being scattered around, which eventually led to the formation of a debris ring. [5] [6]

Post-formation

The rings are believed to have been present approximately 466 million years ago. [1] [7] [8] The Hirnantian glaciation may be a direct result of the rings shielding light from reaching the Earth, [9] and the rings may have existed for up to 40 million years. [9]

Studies

2024 study

The ring was first formally proposed after 21 impact craters from the meteor event were found to be located along a straight band around the Earth's equator. [10] [11] Andrew G. Tomkins, [9] Erin L. Martin [9] and Peter A. Cawood, [9] working with Monash University, released a study in September 2024 that gave evidence on the existence of the rings.

The study noted that all 21 craters produced as a result of the meteor event fell within an equatorial band range of ≤30°, despite the fact that ~70% of the Earth has a crust suitable for the preservation of craters. The study also noted that the chances of all 21 craters falling within the 30° range was one in 25 million, and would be highly unlikely unless the craters were caused by a dissolved ring system. [9]

See also

Related Research Articles

<span class="mw-page-title-main">Impact crater</span> Circular depression in a solid astronomical body formed by the impact of a smaller object

An impact crater is a depression in the surface of a solid astronomical body 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. Impact craters are typically circular, though they can be elliptical in shape or even irregular due to events such as landslides. Impact craters range in size from microscopic craters seen on lunar rocks returned by the Apollo Program to simple bowl-shaped depressions and vast, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.

<span class="mw-page-title-main">Meteorite</span> Solid debris from outer space that hits a planetary surface

A meteorite is a rock that originated in outer space and has fallen to 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.

<span class="mw-page-title-main">Ordovician</span> Second period of the Paleozoic Era 485–444 million years ago

The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period 485.4 Ma to the start of the Silurian Period 443.8 Ma.

<span class="mw-page-title-main">Ring system</span> Ring of cosmic dust orbiting an astronomical object

A ring system is a disc or torus orbiting an astronomical object that is composed of solid material such as gas, dust, meteoroids, planetoids or moonlets and stellar objects.

<span class="mw-page-title-main">Meteor Crater</span> Meteorite impact crater in northern Arizona

Meteor Crater, or Barringer Crater, is an 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.

<span class="mw-page-title-main">Impact event</span> Collision of two astronomical objects

An impact event is a collision between astronomical objects causing measurable effects. Impact events 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, as the impacting body is usually traveling at several kilometres a second, 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.

<span class="mw-page-title-main">Ames crater</span> Meteorite crater in Major County, Oklahoma, United States

Ames crater is a meteorite crater (astrobleme) in Major County, Oklahoma, United States. Ames, Oklahoma is near the center of the structure, which is 30 miles (48 km) southwest of Enid, Oklahoma. Buried under a thick layer of sediment, it was not discovered until 1991. Subsequent drilling within the crater found a large amount of oil and gas. It is one of the largest of six meteor craters associated with oil-producing formations in the United States.

<span class="mw-page-title-main">Araguainha crater</span> Impact crater in Brazil

The Araguainha crater or Araguainha dome is an impact crater on the border of Mato Grosso and Goiás states, Brazil, between the villages of Araguainha and Ponte Branca. With a diameter of 40 kilometres (25 mi), it is the largest known impact crater in South America.

<span class="mw-page-title-main">Glasford crater</span> Impact crater in Illinois

The Glasford crater, also known as the Glasford Disturbance, Glasford Structure, and Glasford Cryptoexplosion Structure, is a buried impact crater in southern Peoria County, Illinois, in the United States. It is one of two known meteor craters in Illinois.

<span class="mw-page-title-main">Kentland crater</span> Impact structure in Indiana, United States

The Kentland structure, also known as the Kentland crater or the Kentland disturbed area, is an impact structure located near the town of Kentland in Newton County, Indiana, United States.

<span class="mw-page-title-main">Neugrund crater</span> Meteorite crater in Estonia

Neugrund is a meteorite crater in Estonia. It is 8 km (5.0 mi) in diameter and was previously estimated to have been formed in the Ordovician around 470 Ma, with later research revealing a possible Cambrian origin. The crater is at the bottom of the sea and is not exposed at the surface. Boulders of gneissic breccia found on the coast of Osmussaar, a nearby island, are believed to have been thrown there by the explosion. It has been proposed that the Neugrund crater was created during the Ordovician meteor event when a hypothetical large asteroid transferred directly into a resonant orbit with Jupiter, which shifted its orbit to intercept Earth.

<span class="mw-page-title-main">Rock Elm Disturbance</span>

The Rock Elm Disturbance is an impact crater in Pierce County, Wisconsin, United States, roughly 40 kilometres (25 mi) southwest of Menomonie. The disturbance is named for Rock Elm, Wisconsin, a nearby town.

<span class="mw-page-title-main">L chondrite</span> Type of meteorite

The L type ordinary chondrites are the second most common group of meteorites, accounting for approximately 35% of all those catalogued, and 40% of the ordinary chondrites. The ordinary chondrites are thought to have originated from three parent asteroids, with the fragments making up the H chondrite, L chondrite and LL chondrite groups respectively.

<span class="mw-page-title-main">101955 Bennu</span> Carbonaceous asteroid

101955 Bennu (provisional designation 1999 RQ36) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999. It is a potentially hazardous object that is listed on the Sentry Risk Table and has the highest cumulative rating on the Palermo Technical Impact Hazard Scale. It has a cumulative 1-in-1,750 chance of impacting Earth between 2178 and 2290 with the greatest risk being on 24 September 2182. It is named after Bennu, the ancient Egyptian mythological bird associated with the Sun, creation, and rebirth.

The Tunnunik impact structure, formerly known as the Prince Albert Impact Crater, is a recently confirmed meteorite impact structure. It is located on Prince Albert Peninsula in the northwestern part of Victoria Island[A] in Canada's Northwest Territories.

<span class="mw-page-title-main">Decorah crater</span> 4.7 million year old meteor crater in Iowa

The Decorah crater, also called the Decorah impact structure, is a possible impact crater located on the east side of the city of Decorah in Iowa, United States. It is thought to have been caused by a meteor about 200 metres (660 ft) wide which struck during the Middle Ordovician Period, circa 470 million years ago.

<span class="mw-page-title-main">Ordovician meteor event</span> Event of around 467 million years ago

The Ordovician meteor event was a dramatic increase in the rate at which L chondrite meteorites fell to Earth during the Middle Ordovician period, about 467.5±0.28 million years ago. This is indicated by abundant fossil L chondrite meteorites in a quarry in Sweden and enhanced concentrations of ordinary chondritic chromite grains in sedimentary rocks from this time.

The Hummeln structure was confirmed, in 2015, as an impact crater in Småland province, Sweden. It is a 1.2 kilometres (0.75 mi) wide depression within Lake Hummeln and is estimated to have formed between 470 and 443 Ma ago, during the Ordovician.

In early 2018 there were eight known impact structures in Sweden. They range in age from 90 mya to 470 mya, and in diameter from 1 km to 52 km. Six of them are exposed, that is they are visible at the surface, in the natural landscape, although their nature and origin might need to be pointed out to the untrained layman.

References

  1. 1 2 "Did Earth once have rings like Saturn?". BBC Newsround. 2024-09-24. Retrieved 2024-09-25.
  2. ↑ "Earth Had a Ring 466 Million Years Ago, Study Says". New York Times. September 20, 2024. Retrieved September 25, 2024.
  3. ↑ Kluger, Jeffrey (2024-09-18). "Earth May Have Had a Ring Like Saturn Once". TIME. Retrieved 2024-09-25.
  4. ↑ Schmitz, Birger (2019-10-22). "Gigantic asteroid collision in the Ordovician period boosted biodiversity on Earth". Research Communities by Springer Nature. Retrieved 2024-05-16.
  5. ↑ "Study: Earth had planetary rings like Saturn 466 million years ago". Earth.com. Retrieved 2024-09-25.
  6. ↑ "Earth Had Ring System 466 Million Years Ago, New Research Suggests". Sci.News. 2024-09-18. Retrieved 2024-09-25.
  7. ↑ Bressan, David (2024-09-23). "Study Suggests Earth May Once Had A Ring System". Forbes. Retrieved 2024-09-25.
  8. ↑ "It Turns Out Earth May Have Once Had a Ring". Popular Mechanics. 2024-09-24. Retrieved 2024-09-25.
  9. 1 2 3 4 5 6 Tomkins, Andrew G.; Martin, Erin L.; Cawood, Peter A. (2024-11-15). "Evidence suggesting that earth had a ring in the Ordovician". Earth and Planetary Science Letters. 646: 118991. doi: 10.1016/j.epsl.2024.118991 . ISSN   0012-821X.
  10. ↑ Cawood A., Peter; Martin, Erin L.; Tomkins, Andrew G. (September 12, 2024). "Evidence suggesting that earth had a ring in the Ordovician". ScienceDirect. Retrieved September 25, 2024.
  11. ↑ "Earth May Have Once Had a Saturn-Like Ring, New Study Says". CNET. Retrieved 2024-09-25.
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