Bennu reached perihelion in early January, so there may be an association between these events and Bennu's orbital location at that time. Multiple particle ejection events were observed between the end of December 2018, the time when OSIRIS-REx entered into Bennu orbit, and February 2019 (Lauretta, Hergenrother, et al., 2019). An unexpected attribute of Bennu is that it is ejecting small particles into space in distinct events. In addition, it is easily accessible in its Earth-like orbit Bennu's orbit has semimajor axis, eccentricity, and inclination ( a, e, i) values of (1.126 au, 0.204, 6.035°). Bennu was chosen for two main reasons: It is a small (490-m diameter) asteroid with a spectral signature consistent with primitive, organic-rich carbonaceous chondrite meteorites determined from ground-based astronomical studies (e.g., Lauretta et al., 2015) and confirmed from spacecraft remote sensing data (Hamilton et al., 2019 Lauretta, DellaGiustina, et al., 2019). Key PointsĪsteroid (101995) Bennu is the target of National Aeronautics and Space Administration's (NASA) sample return mission Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) (Lauretta et al., 2017). Our findings also suggest that fewer ejection events should take place as Bennu moves further away from the Sun, a result that can be tested with future observations. Bennu's ejection events could be caused by the same kinds of meteoroid impacts that created the Moon's asymmetric debris cloud observed by the Lunar Atmosphere and Dust Environment Explorer (LADEE). Crater scaling laws also indicate that these impact energies can reproduce the sizes and masses of the largest observed particles, provided the surface has the cohesive properties of weak, porous materials. We find that 7,000-J impacts on Bennu occur with a biweekly cadence near perihelion, with a preference to strike in the late afternoon (~6 pm local time). Most projectiles that impact Bennu come from nearly isotropic or Jupiter-family comets and have evolved toward the Sun by Poynting-Robertson drag.
Here we examine whether these events could have been produced by sporadic meteoroid impacts using the National Aeronautics and Space Administration's (NASA) Meteoroid Engineering Model 3.0. The three largest events observed during this period, which all occurred 3.5 to 6 hr after local noon, placed numerous particles <10 cm on temporary orbits around Bennu. Send us feedback.Asteroid (101955) Bennu, a near-Earth object with a primitive carbonaceous chondrite-like composition, was observed by the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft to undergo multiple particle ejection events near perihelion between December 2018 and February 2019. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'meteoroid.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors.
2020 Developing film Don’t Look Up would position the Oscar winners as a pair of astronomers whose work leads to the terrifying discovery that a large meteoroid is headed straight for Earth. 2021 After traveling more than 800 miles through the atmosphere, this 132-pound meteoroid flew back into space, according to a paper published in December 2019.Ĭhris Ciaccia, Fox News, 27 Sep. 2021 If an asteroid or meteoroid does not burn up before impact, it is called a meteorite. 2021 Whereas, a meteor is the streak of light seen when an asteroid or meteoroid enter's the Earth's atmosphere, according to NASA. Miriam Fauzia, USA TODAY, 14 July 2021 Cooke, head of NASA's Meteoroid Environment Office, told that a meteoroid is essentially space debris.
Tim Fernholz, Quartz, The light's green hue is likely due to the magnesium contained in the meteoroid. Joshua Hawkins, BGR, 9 June 2022 In one example, the US military only recently confirmed that missile-warning satellites collected information to suggest a 2014 meteoroid came from beyond our galaxy. Recent Examples on the Web Sure, the James Webb being struck by a meteoroid isn’t ideal.
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