Formation age of the lunar crater Giordano Bruno

Abstract

available online at http://meteoritics.org Based on crater size-frequency measurements of small craters (<200 m in diameter) superposed on its continuous ejecta, the formation age of Giordano Bruno is estimated to be 1 to 10 Ma. This is constructive evidence against the crater's medieval age formation hypothesis. Formation age of the lunar crater Giordano Bruno

Impact ejection of lunar meteorites and the age of Giordano Bruno

“…Using Kaguya orbiter data, Plescia et al (2011) consider a historical age for this crater probable. However, the ejecta blanket of Giordano Bruno shows a 1-10 Ma crater retention age (Morota et al, 2009), which appears consistent with detailed observations using Lunar Reconnaissance Orbiter images (Shkuratov et al, 2012).…”

“…It follows that projectiles as small as $30 m and $200 m can produce lunar and martian meteorites, respectively, and the resulting craters are small in size ($1 and $3 km £ on Moon and Mars, respectively; Artemieva and Ivanov, 2004;Fritz et al, 2007a). Based upon surface ages from crater counting, only four lunar craters >20 km £ formed during the last $100 Ma on the Moon (Morota et al, 2009;Grier et al, 2001).…”

Discovery of seifertite in a shocked lunar meteorite

“…In other words, it is likely that such planetesimal collisions that induced complete resetting of 40 Ar- 39 Ar system (and formed high-pressure polymorphs) would be still occurring 2.7 Ga ago at least on the Moon. The 40 Ar-39 Ar radio-isotopic age distribution of impact melts in lunar meteorites 51 would also support that such planetary collisions have continued till around 2.7 Ga on the Moon even after the late heavy bombardments (LHB: 3.8-4.1 Ga) period although it would not be so frequent like the LHB period, which would coincide with crater chronology 48 . Thus, the present results confirmed and strengthened the crater chronological view of the magnitude of collisions in 2-3 Ga on the moon based on the real materials, mineral physics and 40 Ar-39 Ar radio-isotopic chronology.…”

“…The estimated size of asteroid collided on the moon is B0.4 km at least, which formed a crater with a diameter of B7 km at least (Details of calculation process are described in the Supplementary Information). The latest surface observations show that the cumulative frequency of craters with a diameter of B7 km or greater is B10 À 5 /km À 2 around 2-3 Ga (Eratosthenian system) 48 . The area of mare basalt on the moon is B7 Â 10 6 km 2 (ref.…”

The m‐chi decomposition of hybrid dual‐polarimetric radar data with application to lunar craters

“…[20] Byrgius A is a 19 km diameter Copernican crater with an estimated age of 48 Ma that is located in the lunar highlands east of the Orientale Basin and west of Mare Humorum [Wilshire, 1973;Morota et al, 2009]. Visible image data of the region obtained by the LROC wide-angle camera (WAC) at a resolution of 100 m/pixel show optically bright ejecta deposits associated with the crater that extend to radial distances of 100s of km, with near continuous deposits observed to an average radial distance of 70 km (Figure 4a).…”