Concentric Impact Craters on the Moon

(This discussion introduces a theory developed by Dr. Wright. This will be presented in several installments and will be an ongoing discussion,)

Rare Witnesses to High-Energy Catastrophic Impacts

In our model, the solar system bears the scars of two major meteor events rooted in the biblical record of Creation, the Fall, and the global Flood. Rahab, a terrestrial planet formed on Day 4 in the asteroid-belt region consistent with Titius-Bode spacing, was catastrophically disrupted primarily during the Flood year (Genesis 7–8). Its remnants now populate the asteroid belt and delivered intense meteoroid swarms that reshaped planetary surfaces across the solar system. These events were not random cosmic accidents stretched over billions of years but sovereign acts of judgment flowing from the curse introduced at the Fall (Romans 8:20-22), when sin subjected all creation to futility and bondage to corruption. The Moon, with no significant erosion, atmosphere, or plate tectonics to reshape its surface, preserves a far clearer record of these impacts than Earth. Among the most compelling features in this preserved record are the rare concentric impact craters: small lunar craters featuring a perfectly centered inner ring or ridge inside the main outer rim. These structures, along with their characteristically steep walls, provide powerful evidence for the high-velocity, high-energy bombardment delivered by dense swarms of Rahab-derived fragments during the two major meteor events.

Scientific Description of Concentric Lunar Craters

Lunar concentric craters represent a distinct morphological class first systematically documented through Apollo-era photography and later refined with high-resolution imagery from the Lunar Reconnaissance Orbiter Camera (LROC). These craters begin as standard simple impact craters but develop a smaller, nearly perfectly concentric inner ridge or rim within the main structure. Hummocky and chaotic terrain typically fills the annular zone between the outer rim and the inner ring, while the overall crater floor remains anomalously shallow compared to typical bowl-shaped simple craters of similar size. Diameters average around 8 km, with most examples falling well below 15 km. Inner rings generally measure 30 to 60 percent of the outer crater diameter. These features cluster preferentially near mare-highland boundaries and within smaller mare ponds, though scattered examples appear across the lunar surface. Comprehensive catalogs identify only about 114 such craters, rendering them exceptionally rare amid the Moon’s estimated millions of impact features of varying sizes.

Prominent and well-studied examples include Hesiodus A, one of the largest and most visually striking with its clear target-like inner ring visible under appropriate illumination near the edge of Mare Nubium, and Gruithuisen K (centered near 35.4°N, 317.3°E), which displays classic hummocky material between its rings along with a sharply defined inner structure. Many concentric craters appear relatively fresh in the context of the Moon’s surface history. Secular scientists have long debated their origin. While some early proposals suggested formation through impact into layered targets of varying strength that caused concentric slumping, the prevailing uniformitarian explanation today invokes post-impact magmatic intrusion beneath the crater floor. This process, closely related to floor-fractured craters, uplifts the interior and forms the inner ridge as magma pushes upward. The spatial association with volcanic provinces near mare margins lends support to this endogenous mechanism in conventional models. The remarkable symmetry and other traits point to violent formative conditions.

Standard Formation Mechanism

The leading explanation for these features is igneous (volcanic/magmatic) intrusion beneath the original impact crater:

• An impact creates a simple bowl crater.

• Later, magma intrudes underneath, uplifting the floor and forming a concentric ridge as it pushes up the material. This results in anomalously shallow floors and the distinctive inner ring.

• They share similarities with floor-fractured craters, and their locations (near volcanic areas) support this endogenic (internal) process over purely impact-related ones.

  
  

The igneous intrusion model fits the observed properties (shallow floors, spatial distribution, and ages) in many of the features identified. Is there another model that could address these features within our proposed model?

Steep Crater Walls as Evidence of High-Velocity Impacts

A critical morphological detail that bolsters the case for high-energy origins is the steepness of the crater walls. Fresh simple lunar craters commonly display interior upper-wall slopes approaching or reaching the angle of repose for lunar regolith and bedrock, often in the range of 27 to 35 degrees, with some localized segments even steeper. Higher impact velocities enhance excavation efficiency, generate greater initial rim heights, and produce more symmetric and intense shock-wave propagation through the target material. This leads to steeper initial wall profiles prior to any gravitational modification or collapse. Laboratory impact experiments and numerical crater-scaling laws demonstrate that hypervelocity impacts, exceeding 20 km per second, create sharper excavation flows, increased volumes of melt and vapor, and more coherent structural responses that help preserve steep rim slopes in the short term after formation.

In concentric craters specifically, both the main outer rims and the inner rings frequently exhibit these pronounced steep slopes. The inner ring often appears as a steep-walled miniature crater in its own right. When combined with the anomalously shallow floors and hummocky inter-ring zones, this morphology records rapid and violent modification either during or immediately following the primary impact. Such features align far more readily with clustered hypervelocity strikes than with the slower, more isolated impacts characteristic of today’s sparse population of near-Earth objects. Over time, degradation processes such as mass wasting, seismic shaking from later impacts, and micrometeorite gardening gradually reduce wall steepness. Consequently, the steepest concentric examples likely represent the freshest and most energetically formed members of the class. These traits collectively indicate impact conditions involving exceptionally high kinetic energies not typical of uniformitarian bombardment rates.

The Rarity and Implications for High-Energy Impacts

The extreme rarity of perfectly concentric craters, largely restricted to smaller diameter ranges, stands as a diagnostic signature in itself. If lunar cratering resulted primarily from steady-state bombardment across 4.5 billion years, as uniformitarian geology assumes, symmetric dual-ring morphologies should appear far more frequently and across a broader size spectrum. Instead, their scarcity, paired with steep walls, elevated depth-to-diameter ratios in fresh specimens, and persistently shallow floors, demands highly specific formation conditions: extreme kinetic energies, precise clustering of impactor trajectories, and powerful shock-wave interactions capable of generating near-perfect concentric symmetry. This combination of events provides a reasonable resolution to these anomalous features.

A unique characteristic within the Rahab model, demonstrates that these observations fit naturally into the physics of a planetary-scale disruption. As Rahab fragmented under tidal stresses and internal destabilization during the Flood-year cataclysm, it produced dense swarms of high-velocity debris. Dynamical modeling of such breakup events reveals that fragments often travel in clustered streams, raising the probability of near-simultaneous or closely sequenced multi-body impacts on targets like the Moon. In this scenario, a primary Rahab-derived impactor excavates the outer crater bowl, while trailing fragments or shock-induced secondaries strike near the center. The resulting reinforced shock waves trigger central rebound and floor uplift, forming the inner ring complete with steep walls. The immense energies released, far surpassing those of modern impactors, account for the symmetric violence, localized melting, hummocky textures, and preservation of steep profiles, all without dependence on later unrelated volcanic activity.

Two Major Meteor Events: Echoes of the Fall and the Flood Judgment

This framework identifies two distinct meteor episodes, both ultimately rooted in the effects of the Fall yet manifested with differing intensity.

The first, more subtle event corresponds to the immediate cosmic repercussions of Adam’s sin (Genesis 3; Romans 5:12; Romans 8:20-22). The entrance of death and corruption into creation destabilized the original “very good” solar system. This phase introduced orbital perturbations and minor collisional cascades among bodies formed on Day 4, including early fragments shed from a still largely intact but now cursed Rahab. These produced scattered high-energy impacts, many of which are recorded in the heavily cratered lunar highlands as older, more degraded features.

The second and far more devastating event unfolded during the Flood year itself. Scripture describes the breaking open of the “windows of heaven” and the “fountains of the great deep” (Genesis 7:11). In the Rahab model, God sovereignly employed the complete disruption of Rahab as a key instrument of global judgment. The ensuing dense meteoroid swarm delivered the majority of the visible cratering on the Moon and contributed significantly to terrestrial effects during the Flood. Concentric craters, with their steep walls and requirements for clustered hypervelocity impacts, function as diagnostic markers of this swarm’s exceptional density and energy. Positioned often near mare boundaries, where impact-triggered flood basalts later flowed, these features capture a frozen moment of the cataclysm that Earth’s global waters and rapid sedimentation largely reworked or buried. Secondary ejecta from these lunar events, known as lunaites, further support the model, as many meteorites recovered on Earth today share chemical affinities with Apollo lunar samples.

This young-creation interpretation remains scientifically coherent. The calculated kinetic energies available from Rahab fragments readily satisfy the requirements for producing steep-walled concentric morphologies. The observed rarity matches the brief, intense duration of a catastrophic swarm far better than gradual accumulation over eons. Isotopic signatures, crater statistics, and sample chemistry from lunar missions all align more comfortably with a recently disrupted planetary source than with ancient, incremental processes.

Theological and Evidential Significance

Concentric impact craters on the Moon, distinguished by their rare perfect symmetry and steep walls, serve as enduring testimonies to the reliability and authority of God’s Word. They visibly echo the curse that followed the Fall and the purifying, global judgment of the Flood. In doing so, they remind us that the entire creation continues to “groan” under the weight of sin (Romans 8:22) while simultaneously pointing believers forward to the promised new creation in which “the former things will not be remembered” (Isaiah 65:17; Revelation 21:1). Just as the catastrophic destruction of Rahab and its meteoritic legacy proclaim the Creator’s sovereign power and righteous justice, these remarkable lunar features call us to place full trust in the biblical timeline, from a literal six-day Creation to a worldwide Flood, rather than in speculative deep-time narratives that contradict Scripture.

Researchers continue to explore these and related connections through detailed analysis of mission data and dynamical modeling. This model not only reconciles a wide range of astronomical and geological observations with the clear teaching of Scripture but also builds confidence in the gospel by demonstrating that the heavens declare the glory of God (Psalm 19:1), even through the visible scars of divine judgment. We invite readers to examine the evidence prayerfully, consider its profound implications for history and eternity, and marvel at the sovereign God who upholds all things by the word of His power (Colossians 1:17) while extending redemption and new life through Jesus Christ our Lord.