Velocity distribution of larger meteoroids and small asteroids impacting Earth

Drolshagen, E.; Ott, T.; Koschny, D.; Drolshagen, G.; Schmidt, Anna Kristiane; Poppe, Björn

doi:10.1016/j.pss.2020.104869

Cited by 17 publications

(8 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The velocities in the CNEOS database are not free of errors either. Drolshagen et al (2020) mention that a common velocity error assumed for the CNEOS data is about 1-2 km s −1 , Brown et al (2016) estimated the uncertainty to be in the order of 0.1-0.2 km s −1 , and Devillepoix et al (2019) found for two of ten studied events velocity deviations from independent observations of up to 28%. Furthermore, to calculate the diameter of the impacting object, a spherical shape and a density of 3000 kg m −3 have been assumed.…”

Section: Discussionmentioning

confidence: 93%

“…Meteors are caused by small extraterrestrial dust particles, meteoroids, entering the Earth's atmosphere at very high velocities in the range 11.1-73.6 km s −1 (see e.g. Drolshagen et al 2020). Meteors with an absolute magnitude brighter −4 are called fireballs, and the brightest and rarest of which are sometimes referred to as bolides.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Infrasound signals of fireballs detected by the Geostationary Lightning Mapper

Ott

Drolshagen

Koschny

et al. 2021

A&A

View full text Add to dashboard Cite

Context. Fireballs are particularly bright meteors produced by large meteoroids or small asteroids that enter the Earth’s atmosphere. These objects, of sizes from some tens of centimetres to a few metres, are difficult to record with typical meteor detection methods. Therefore, their characteristics and fluxes are still not well known. Infrasound signals can travel particularly well through the atmosphere over large distances. Impacting meteoroids and asteroids can produce those signals, as well as space-detectable optical signatures. Aims. This paper aims to study and compare fireball data from the Geostationary Lightning Mappers (GLMs) on board the two Geostationary Observational Environmental Satellites (GOES-16 and GOES-17) and the data from the infrasound stations of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organisation (Vienna, Austria). The overall goal is a more accurate energy estimation of meteoroids and asteroids as well as a better understanding of both methods. Methods. The data consist of the brightest 50 events in the GLM database, as identified by recorded peak energy. For 24 of those fireballs, a significant signature could be identified in infrasound data. The data are supplemented by, if available, optical fireball data based on US government sensors on satellites provided by NASA’s Center for Near-Earth Object Studies (CNEOS). Results. The energies as computed from the GLM data range from 3.17 × 107 J up to 1.32 × 1012 J with a mean of 1.65 × 1011 J. The smallest meteoroid recorded by infrasound had an energy of about 1.8 × 109 J, the largest one of about 9.6 × 1013 J, and the mean energy is 5.2 × 1012 J. For 19 events, data were simultaneously available from all three data sources. A comparison between the energy values for the same event as determined from the different data sources indicates that CNEOS tends to give the lowest energy estimations. Analysis of infrasound data results in the largest derived energies. Conclusions. The energies derived using the three methods often deviate from one another by as much as an order of magnitude. This indicates a potential observational bias and highlights uncertainties in fireball energy estimation. By determining the fireball energy with another independent method, this study can help to better quantify and address this range of uncertainty.

show abstract

Section: Discussionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Infrasound signals of fireballs detected by the Geostationary Lightning Mapper

Ott

Drolshagen

Koschny

et al. 2021

A&A

View full text Add to dashboard Cite

show abstract

“…The typical velocity uncertainty for meter-scale impactors in the CNEOS catalog was estimated by Brown et al (2016) and Granvik & Brown (2018) to be less than 1 km s −1 , but 2 of 10 events analyzed by Devillepoix et al (2019) have discrepancies with alternate measurements of up to 28% in speed. Drolshagen et al (2020) noted that the CNEOS catalog includes two objects that were detected in space before impact, 2008 TC 3 and 2018 LA, with respective measurement errors of 0.3 and 0.52 km s −1 on the geocentric impact speed. These papers underlined the importance of uncertainties and motivated us to retrieve the measurement uncertainties for the 2014 January 8 meteor specifically.…”

Section: Trajectorymentioning

confidence: 99%

A Meteor of Apparent Interstellar Origin in the CNEOS Fireball Catalog

Siraj

Loeb

2022

ApJ

View full text Add to dashboard Cite

The earliest confirmed interstellar object, ‘Oumuamua, was discovered in the solar system by Pan-STARRS in 2017, allowing for a calibration of the abundance of interstellar objects of its size ∼100 m. This was followed by the discovery of Borisov, which allowed for a similar calibration of its size ∼0.4–1 km. One would expect a much higher abundance of significantly smaller interstellar objects, with some of them colliding with Earth frequently enough to be noticeable. Based on the CNEOS catalog of bolide events, we identify the ∼0.45 m meteor detected at 2014 January 8 17:05:34 UTC as originating from an unbound hyperbolic orbit. The U.S. Department of Defense has released an official letter stating that “the velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory,” which we rely on here as confirmation of the object’s interstellar trajectory. Based on the data provided by CNEOS, we infer that the meteor had an asymptotic speed of v ∞ ∼ 42.1 ± 5.5 km s−1 outside of the solar system. Note that v ∞ here refers to the velocity of the meteor outside the solar system, not the velocity of the meteor outside the atmosphere. Its origin is approximately toward R.A. 49.°4 ± 4.°1 and decl. 11.°2 ± 1.°8, implying that its initial velocity vector was 58 ± 6 km s−1 away from the velocity of the local standard of rest (LSR).

show abstract

“…For a parabolic trajectory, this mean velocity corresponds to a value of ~13.8 km/s for the velocity of impacting the Earth. Drolshagen et al (2020) noticed that, in the papers they cited, the peak of the distribution of velocities of bodies impacting the Earth was at ~13−15 km/s, while the velocities of meteorites entering the terrestrial atmosphere may change in a range of 11 to 73 km/s, and meteoroids with velocities of 9.8 and 10.9 km/s were also detected. This means that some meteoroids approach the activity sphere of the Earth with almost zero velocity, since the parabolic velocity on the Earth's surface is 11.2 km/s.…”

Section: Probabilities Of Collisions Of Near-earth Objects With the Moonmentioning

confidence: 99%

Number of Near-Earth Objects and Formation of Lunar Craters over the Last Billion Years

2020

View full text Add to dashboard Cite

We compare the number of lunar craters larger than 15 km across and younger than 1.1 Ga to the estimates of the number of craters that could have been formed for 1.1 Ga if the number of near-Earth objects and their orbital elements during that time were close to the corresponding current values. The comparison was performed for craters over the entire lunar surface and in the region of the Oceanus Procellarum and maria on the near side of the Moon. In these estimates, we used the values of collision probabilities of near-Earth objects with the Moon and the dependences of the crater diameters on the impactor sizes. According to the estimates made by different authors, the number density of known Copernican craters with diameters D≥15 km in mare regions is at least double the corresponding number for the remaining lunar surface. Our estimates do not contradict the growth in the number of near-Earth objects after probable catastrophic fragmentations of large main-belt asteroids, which may have occurred over the recent 300 Ma; however, they do not prove this increase. Particularly, they do not conflict with the inference made by Mazrouei et al. (2019) that 290 Ma ago the frequency of collisions of near-Earth asteroids with the Moon increased by 2.6 times. The number of Copernican lunar craters with diameters not smaller than 15 km is probably higher than that reported by Mazrouei et al. (2019). For a probability of a collision of an Earth-crossing object (ECO) with the Earth in a year equaled to 10-8 , our estimates of the number of craters agree with the model, according to which the number densities of the 15-km Copernican craters for the whole lunar surface would have been the same as that for mare regions if the data by Losiak et al. (2015) for D < 30 km were as complete as those for D > 30 km. With this collision probability of ECOs with the Earth and for this model, the cratering rate may have been constant over the recent 1.1 Ga.

show abstract

Velocity distribution of larger meteoroids and small asteroids impacting Earth

Cited by 17 publications

References 42 publications

Infrasound signals of fireballs detected by the Geostationary Lightning Mapper

Infrasound signals of fireballs detected by the Geostationary Lightning Mapper

A Meteor of Apparent Interstellar Origin in the CNEOS Fireball Catalog

Number of Near-Earth Objects and Formation of Lunar Craters over the Last Billion Years

Contact Info

Product

Resources

About