Near-Earth object 2022 EB5: From atmospheric entry to physical properties and orbit

Abstract

Context. The near-Earth object (NEO) 2022 EB5 is the fifth NEO found prior to entering the Earth's atmosphere. It fragmented over the Norway Sea on 2022 March 11 about two hours after being discovered by the astronomer Krisztián Sárneczky at Konkoly Observatory in Hungary. The Center for Near-Earth Object Studies (CNEOS) at NASA detected the visible radiation emitted at the time of its atmospheric entry. The Jet Propulsion Laboratory (JPL) and European Space Agency (ESA) derived its orbital elements based on observations of its pre-atmospheric orbit. Aims. This paper aims to calculate the physical properties of this NEO, in particular, the bulk strength, type of the material, albedo, size, and mass, based on observations of its peak brightness at the time of its atmospheric entry. In addition, the heliocentric elements are computed from its interaction with Earth's atmosphere and compared with those derived from observations by JPL and ESA, respectively, to evaluate the accuracy of our method. Methods. The flight equations of 2022 EB5 were inversely integrated from the peak brightness to the atmospheric boundary via the fourth-order Runge-Kutta method. A pancake model was utilized to simulate the fragmentation of the impactor. Parameters needed to complete the integration process that were unknown were set to be optimization variables and determined via a genetic algorithm. Results. The results obtained show that 2022 EB5 was most likely a C-type asteroid with a maximal bulk strength of 2 MPa, diameter of 5–6 m, cometary density, and very low albedo that is no greater than 0.025. In addition, considering the effects of the atmosphere is helpful in getting a more accurate measurement for the semi-major axis, eccentricity, and inclination, although the accuracy of orbital elements strongly depends on the accuracy of USG sensors.

Precise Distance Measurement for a Near-Earth Asteroid by the Refined Rotational Reflex Velocity Method

“…A population of more than 1 million suffered from the impact and atmospheric explosion of a 20 m wide asteroid, which was the largest impact on Earth by an asteroid since 1908 (Popova et al 2013). Recently, the impact events of asteroids 2008 TC 3 (Jenniskens et al 2009) and 2022 EB 5 (Geng et al 2023) are well known. PHAs are large enough to cause significant regional damage, which should be continuously monitored.…”