scholarly journals The Potentially Hazardous Asteroid 2000 SG344

2016 ◽  
Vol 25 (2) ◽  
Author(s):  
I. Wlodarczyk
Keyword(s):  
Software Package ◽  
Optical Observations ◽  
The Earth ◽  
Near Earth Asteroids

AbstractWe computed impact solutions for the potentially dangerous asteroid 2000 SG344, based on 31 optical observations from 1999 May 15.20482 UTC to 2010 October 29 03.60723 UTC. Using the freely available OrbFit Software Package, we can follow its orbit forward in time searching for close approaches to the Earth, which can lead to possible impacts up to 2113. The asteroid 2000 SG344 belongs to the class of the so-called possible recovery Near Earth Asteroids and can be recovered in 2028. Its ephemerides for observational window in 2028 are presented.

scholarly journals The Potentially Dangerous Asteroid (101955) Bennu

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
I. Włodarczyk
Keyword(s):  
Time Evolution ◽  
Software Package ◽  
Optical Observations ◽  
Orbital Elements ◽  
Radar Observations ◽  
The Earth ◽  
The Future ◽  
The Mean ◽  
Orbital Resonances ◽  
Selection Of

We computed impact solutions of the potentially dangerous asteroid (101955) Bennu based on 569 optical observations from September 11.40624 UTC, 1999 to January 20.11189 UTC, 2013, and 29 radar observations from September 21, 1999, through September 29, 2011. Using the freely available OrbFit software package, we can follow its orbit forward in the future searching for close approaches with the earth, which can lead to possible impacts up to 2200. With the A2 nongravitational parameter in the motion of the asteroid (101955) Bennu we computed possible impact solutions using different JPL planetary and lunar ephemerides and different number of additional massive perturbed asteroids. The possible impact path of risk for 2175 is presented. Additionally, we computed possible impact solutions using the normal places method of the selection of Bennu’s astrometric observations. Moreover, we computed time evolution of the mean orbital elements and the orbital nodes of Bennu 5 kyr in the backwards and 1 kyr in the future using the Yarkovsky effects. We computed the mean motion and secular orbital resonances of the Bennu. We also computed the influence of the JPL planetary and lunar ephemerides DE403, DE405, DE406, DE414, and DE423 on the close approaches of the asteroid (101955) Bennu with the earth.

Statistical results on discovered near-Earth asteroids

1999 ◽  
Vol 173 ◽  
pp. 81-86
Author(s):  
S. Berinde
Keyword(s):  
Dynamical Evolution ◽  
Minor Planet ◽  
Orbital Elements ◽  
The Earth ◽  
Near Earth Asteroids ◽  
Statistical Results

AbstractThe first part of this paper gives a recent overview (until July 1st, 1998) of the Near-Earth Asteroids (NEAs) database stored at Minor Planet Center. Some statistical interpretations point out strong observational biases in the population of discovered NEAs, due to the preferential discoveries, depending on the objects’ distances and sizes. It is known that many newly discovered NEAs have no accurately determinated orbits because of the lack of observations. Consequently, it is hard to speak about future encounters and collisions with the Earth in terms of mutual distances between bodies. Because the dynamical evolution of asteroids’ orbits is less sensitive to the improvement of their orbital elements, we introduced a new subclass of NEAs named Earth-encounter asteroids in order to describe more reliably the potentially dangerous bodies as impactors with the Earth. So, we pay attention at those asteroids having an encounter between their orbits and that of the Earth within 100 years, trying to classify these encounters.

scholarly journals New Tools for the Optimized Follow-Up of Imminent Impactors

Universe ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Maddalena Mochi ◽  
Giacomo Tommei
Keyword(s):  
Orbit Determination ◽  
Main Belt ◽  
Impact Monitoring ◽  
The Earth ◽  
Current Observation ◽  
Short Period ◽  
Fly Eye ◽  
Near Earth Asteroids ◽  
Near Earth Objects

The solar system is populated with, other than planets, a wide variety of minor bodies, the majority of which are represented by asteroids. Most of their orbits are comprised of those between Mars and Jupiter, thus forming a population named Main Belt. However, some asteroids can run on trajectories that come close to, or even intersect, the orbit of the Earth. These objects are known as Near Earth Asteroids (NEAs) or Near Earth Objects (NEOs) and may entail a risk of collision with our planet. Predicting the occurrence of such collisions as early as possible is the task of Impact Monitoring (IM). Dedicated algorithms are in charge of orbit determination and risk assessment for any detected NEO, but their efficiency is limited in cases in which the object has been observed for a short period of time, as is the case with newly discovered asteroids and, more worryingly, imminent impactors: objects due to hit the Earth, detected only a few days or hours in advance of impacts. This timespan might be too short to take any effective safety countermeasure. For this reason, a necessary improvement of current observation capabilities is underway through the construction of dedicated telescopes, e.g., the NEO Survey Telescope (NEOSTEL), also known as “Fly-Eye”. Thanks to these developments, the number of discovered NEOs and, consequently, imminent impactors detected per year, is expected to increase, thus requiring an improvement of the methods and algorithms used to handle such cases. In this paper we present two new tools, based on the Admissible Region (AR) concept, dedicated to the observers, aiming to facilitate the planning of follow-up observations of NEOs by rapidly assessing the possibility of them being imminent impactors and the remaining visibility time from any given station.

scholarly journals The potentially hazardous NEA 2001 BB16

2019 ◽  
Vol 28 (1) ◽  
pp. 180-190
Author(s):  
Ireneusz Wlodarczyk
Keyword(s):  
Mean Value ◽  
Optical Observations ◽  
Uniform Sampling ◽  
The Earth ◽  
22Nd Century ◽  
Lyapunov Time ◽  
Gravitational Model ◽  
Calculated Probability ◽  
Potential Impact ◽  
The Impact

AbstractWe computed the impact solutions of the potentially dangerous Near Earth Asteroid (NEA) 2001 BB16 based on 47 optical observations from January 20.08316 UTC, 2001, through February 09.15740 UTC, 2016, and one radar observation from January 19.90347 UTC, 2016. We used two methods to sample the starting Line of Variation (LOV). First method, called thereafter LOV1, with the uniform sampling of the LOV parameter, out to LOV = 5 computing 3000 virtual asteroids (VAs) on both sides of the LOV, which gives 6001 VAs and propagated their orbits to JD2525000.5 TDT=February 12, 2201. We computed the non-gravitational parameterA2=(34.55±7.38)·10–14 au/d2 for nominal orbit of 2001 BB16 and possible impacts with the Earth until 2201. For potential impact in 2195 we find A2=20.0·10−14 au/d2. With a positive value of A2, 2001 BB16 can be prograde rotator. Moreover, we computed Lyapunov Time (LT) for 2001 BB16, which for all VAs, has a mean value of about 25 y. We showed that impact solutions, including the calculated probability of a possible collision of a 2001 BB16 asteroid with the Earth depends on how to calculate and take into account the appropriate gravitational model, including the number of perturbing massive asteroids. In some complicated cases, it may depend also on the number of clones calculated for a given sigma LOV1. The second method of computing the impact solutions, called thereafter LOV2, is based on a non-uniformly sampling of the LOV. We showed that different methods of sampling the LOV can give different impact solutions, but all computed dates of possible impacts of the asteroid 2001 BB16 with the Earth occur in accordance at the end of the 22nd century.

scholarly journals Dangerous Voltages due to Direct Lightning Strike into the Communication Tower

2007 ◽  
Vol 3 (1) ◽  
pp. 44
Author(s):  
Slavko Vujević ◽  
Petar Sarajčev
Keyword(s):  
Software Package ◽  
Electromagnetic Coupling ◽  
Circular Cross Section ◽  
Potential Method ◽  
Lightning Strike ◽  
The Earth ◽  
Lumped Parameter ◽  
Leakage Resistance ◽  
Tower Structure ◽  
Analytical Expressions

This paper presents a novel technique for computing dangerous voltages due to direct lightning strike into the communication tower and associated earthing system, which is based on the use of the well-known ATP-EMTP software package. The earthing grid and the communication tower structure are approximated by the circular cross section conductors. In numerical model, conductors are subdivided into segments (1D finite elements) and Clark's model with distributed constant parameters is then applied. Because of the limitations of ATP-EMTP software package, the leakage resistance of buried segments is modelled as additional lumped parameter. Analytical expressions for distributed and lumped segment parameters are derived using the average potential method. Mutual electromagnetic coupling between segments is neglected due to the limitations imposed by the ATP-EMTP software package, which is based on transmission line approach. Separate computer program is developed for obtaining the earth surface transient potential distribution, from which step and touch voltages are then computed.

scholarly journals The partial banana mapping: a robust linear method for impact probability estimation

2019 ◽  
Vol 492 (3) ◽  
pp. 4546-4552
Author(s):  
Dmitrii E Vavilov
Keyword(s):  
Coordinate System ◽  
Confidence Region ◽  
Linear Method ◽  
Probability Estimation ◽  
Curvilinear Coordinate System ◽  
The Earth ◽  
Curvilinear Coordinate ◽  
Near Earth Asteroids ◽  
The Impact ◽  
Confidence Ellipsoid

ABSTRACT This paper presents a robust linear method for impact probability estimation of near-Earth asteroids with the Earth. This method is a significantly modified and improved method, which uses a special curvilinear coordinate system associated with the nominal orbit of an asteroid. One of the coordinates of this system is the mean anomaly in the osculating orbit of an asteroid. A normal distribution of errors of coordinates and velocities of this system is assumed. Because of the usage of the curvilinear coordinate system, the fact that the confidence region is curved and stretched mainly along the nominal asteroid orbit is taken into account. On the main axis of the curvilinear confidence ellipsoid the virtual asteroid, which is the closest to the Earth, is found. The part of the curvilinear confidence ellipsoid, around the found virtual asteroid, is obtained and mapped on to its target plane. The impact probability is calculated as the probability of the asteroid being in the region of the found virtual asteroid multiplied by the probability of a collision of the found virtual asteroid with the Earth. This approach is shown to give more accurate and trustworthy results than the target plane method.

scholarly journals 160 m Pulsations in the Magnetosphere of the Earth Possibly Caused by Oscillations of the Sun

1983 ◽  
Vol 66 ◽  
pp. 451-455
Author(s):  
B.M. Vladimirsky ◽  
V.P. Bobova ◽  
N.M. Bondarenko ◽  
V.K. Veretennikova
Keyword(s):  
Uv Radiation ◽  
Wavelength Range ◽  
Optical Observations ◽  
Stable Phase ◽  
Expansion Velocity ◽  
The Sun ◽  
Flux Variation ◽  
Geophysical Observatory ◽  
The Earth ◽  
Solar Uv

AbstractThe measurements of the amplitudes envelope of Pc 3–4 geomagnetic micropulsations obtained at the Borok Geophysical Observatory were analysed by the cosinor method to search for magnetospheric pulsations with a period of about 160 m. 216 days of observations in 1974–1978 were used. It was found that Pc3–4 amplitudes are modulated by the period 160.010 m with a stable phase. The maximum of the Pc3–4 amplitudes follows approximately 20 m after the maximum of the solar expansion velocity (for the center of the disk) in the optical observations of Severny et al. This modulation of the Pc3–4 amplitudes could be caused by the presence of an oscillating component in solar UV radiation over the wavelength range 100-900 Å. The amplitude of the UV flux variation may be as large as 2–4%.

The problem of the near-earth asteroids encountering the earth

2000 ◽  
Vol 43 (10) ◽  
pp. 1114-1120 ◽  
Author(s):  
Ji Jianghui ◽  
Liu Lin
Keyword(s):  
The Earth ◽  
Near Earth Asteroids

scholarly journals Direct and indirect capture of near-Earth asteroids in the Earth–Moon system

2017 ◽  
Vol 129 (1-2) ◽  
pp. 57-88 ◽  
Author(s):  
Minghu Tan ◽  
Colin McInnes ◽  
Matteo Ceriotti
Keyword(s):  
Moon System ◽  
The Earth ◽  
Near Earth Asteroids
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