Impact craters of Venus: Analysis of Venera 15 and 16 data

Ivanov, B. A.; Basilevsky, A. T.; Kryuchkov, V. P.; Chernaya, I. M.

doi:10.1029/jb091ib04p0d413

Cited by 107 publications

(78 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dense atmosphere on Venus causes meteoroids to be disrupted in the atmosphere so that the smallest impact crater on Venus is a few km in diameter. The longer path length causes meteoroids entering the atmosphere at low angles to be preferentially filtered out, and the size-frequency distribution of craters may be deficient in low-angle impacts up to 20-30 km in diameter (Tauber and Kirk 1976;Ivanov et al 1986;Ivanov 1990;Herrick and Phillips 1994). Therefore, we surveyed only craters >30 km in diameter.…”

Section: Venusian Datamentioning

confidence: 99%

“…Meteoroids entering the venusian atmosphere are disrupted by aerodynamic drag forces. The meteoroid will deform and break apart upon entry, and small meteoroids, apparently, will explode in the atmosphere so that no craters below ~2 km in diameter form on Venus (Tauber and Kirk 1976;Ivanov et al 1986). For larger meteoroids, the fragments will disperse.…”

Section: Craters <15 Km In Diametermentioning

confidence: 99%

See 1 more Smart Citation

The shape and appearance of craters formed by oblique impact on the Moon and Venus

Herrick

Forsberg-Taylor

2003

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-We surveyed the impact crater populations of Venus and the Moon, dry targets with and without an atmosphere, to characterize how the 3-dimensional shape of a crater and the appearance of the ejecta blanket varies with impact angle. An empirical estimate of the impact angle below which particular phenomena occur was inferred from the cumulative percentage of impact craters exhibiting different traits. The results of the surveys were mostly consistent with predictions from experimental work. Assuming a sin 2 Q dependence for the cumulative fraction of craters forming below angle Q, on the Moon, the following transitions occur: <~45 degrees, the ejecta blanket becomes asymmetric; <~25 degrees, a forbidden zone develops in the uprange portion of the ejecta blanket, and the crater rim is depressed in that direction; <~15 degrees, the rim becomes saddle-shaped; <~10 degrees, the rim becomes elongated in the direction of impact and the ejecta forms a "butterfly" pattern. On Venus, the atmosphere causes asymmetries in the ejecta blanket to occur at higher impact angles. The transitions on Venus are: <~55 degrees, the ejecta becomes heavily concentrated downrange; <~40 degrees, a notch in the ejecta that extends to the rim appears, and as impact angle decreases, the notch develops into a larger forbidden zone; <~10 degrees, a fly-wing pattern develops, where material is ejected in the crossrange direction but gets swept downrange. No relationship between location or shape of the central structure and impact angle was observed on either planet. No uprange steepening and no variation in internal slope or crater depth could be associated with impact angle on the Moon. For both planets, as the impact angle decreases from vertical, first the uprange and then the downrange rim decreases in elevation, while the remainder of the rim stays at a constant elevation. For craters on Venus <~15 km in diameter, a variety of crater shapes are observed because meteoroid fragment dispersal is a significant fraction of crater diameter. The longer path length for oblique impacts causes a correlation of clustered impact effects with oblique impact effects. One consequence of this correlation is a shallowing of the crater with decreasing impact angle for small craters.

show abstract

Section: Venusian Datamentioning

confidence: 99%

Section: Craters <15 Km In Diametermentioning

confidence: 99%

The shape and appearance of craters formed by oblique impact on the Moon and Venus

Herrick

Forsberg-Taylor

2003

Meteorit & Planetary Scien

View full text Add to dashboard Cite

show abstract

“…A population of impact craters was found that suggested a mean surface age for the studied area to be 0.5 to 1 b.y. [Ivanov et al, 1986]. These discoveries suggested a planetary geology that is very different from that of Earth.…”

Section: History Of Venus Explorationmentioning

confidence: 99%

Surface evolution of Venus

Basilevsky

McGill

2007

Geophysical Monograph Series

View full text Add to dashboard Cite

This chapter contains short descriptions of material units and structures observed on the surface of Venus as well as an abbreviated history of discoveries, that led to the current knowledge of this planet's geology. It is shown that observed units and structures are broadly similar and commonly exhibit similar age sequences in different regions of the planet, although there is debate as to what degree these sequences can be integrated into any single global stratigraphic model. There is a broad consensus concerning the recent general geodynamic style of Venus (no plate tectonics), on the dominating role of basaltic volcanism in the observed crust-forming processes, and on the significant roles of both compressional and extensional tectonic deformation. Also not under debate is that we see the morphologic record of only the last ~1 b.y. (or less) of the history of this planet and that during this time period the role of exogenic resurfacing was very minor. Several important unresolved questions of Venus geology are formulated and suggestions for future missions, that could lead to resolving them are given.

show abstract

“…The age of the surface of Venus is relatively young, probably a few hundred Ma (Ivanov et al, 1986;Campbell et al, 1991;Phillips et al, 199Ia), but older than that of the terrestrial oceanic crust, which has a mean age of about 100 Ma. In summary, the surface of Venus appears to be dominated by basaltic volcanism, and the elevated regions are crumpled-up basaltic crust.…”

Section: Venusmentioning

confidence: 99%

Accretion in the inner nebula: The relationship between terrestrial planetary compositions and meteorites*

Taylor

1991

Meteoritics

View full text Add to dashboard Cite

Abstract-The bulk compositions ofthe terrestrial planets are assessed. Venus and Earth probably have similar bulk compositions, but Mars is enriched in volatile elements. The inner planets are all depleted in volatile elements, as shown by KJU ratios, relative to most meteorites and the CI primordial values. Terrestrial upper mantle Mg/Si ratios are high compared with CI data. If they are representative of the bulk Earth, then the Earth accreted from a segregated suite of planetesimals that had non-chondritic major element abundances. The CI meteorite abundances, despite aqueous alteration, match the solar data and provide the best estimate for the composition of the solar nebula, including the iron abundance. The widespread depletion of volatile elements in the inner solar nebula is most likely caused by heating related to early violent solar activity (e.g., T Tauri and FU Orionis stages) which, for example, drove water out to a "snow line" in the vicinity of Jupiter. The variation in composition among the meteorites and the apparent lack of mixing among the groups indicates accretion from narrow feeding zones. There appears to have been little mixing between meteorite and planetary formation zones, as shown by the oxygen isotope variations, lack of mixing of meteorite groups, and differences in KJU ratios. In summary, it appears that the final accretion of planets did not result in widespread homogenization, and that mixing zones were not more than about 0.3 A.U. wide. Although the composition of the Moon is unique, and its origin due to an essentially random event, its presence reinforces the planetesimal hypothesis and the importance of stochastic processes during planetary accretion in the inner solar system.

show abstract

Impact craters of Venus: Analysis of Venera 15 and 16 data

Cited by 107 publications

References 8 publications

The shape and appearance of craters formed by oblique impact on the Moon and Venus

The shape and appearance of craters formed by oblique impact on the Moon and Venus

Surface evolution of Venus

Accretion in the inner nebula: The relationship between terrestrial planetary compositions and meteorites*

Contact Info

Product

Resources

About