scholarly journals Comment on “A cometary origin for atmospheric martian methane” by Fries et al., 2016

2017 ◽  
Author(s):  
M.M.J. Crismani ◽  
N.M. Schneider ◽  
J.M.C Plane
Keyword(s):  
Cometary Origin

scholarly journals A carbonaceous chondrite and cometary origin for icy moons of Jupiter and Saturn

2020 ◽  
Vol 530 ◽  
pp. 115920 ◽  
Author(s):  
Adrien Néri ◽  
François Guyot ◽  
Bruno Reynard ◽  
Christophe Sotin
Keyword(s):  
Carbonaceous Chondrite ◽  
Icy Moons ◽  
Cometary Origin

1999 KUIPER PRIZE LECTURE Cometary Origin of the Biosphere

Icarus ◽  
2000 ◽  
Vol 146 (2) ◽  
pp. 313-325 ◽  
Author(s):  
A Delsemme
Keyword(s):  
Cometary Origin

scholarly journals Dust in the Solar System

1989 ◽  
Vol 44 (10) ◽  
pp. 877-882 ◽  
Author(s):  
H. Fechtig
Keyword(s):  
Solar Irradiation ◽  
Dust Particles ◽  
Normal Density ◽  
Dust Grains ◽  
Cometary Dust ◽  
In Situ Experiments ◽  
Asteroidal Belt ◽  
Comet Halley ◽  
Cometary Origin

Abstract Properties of cometary dust particles are better known since the space missions to Comet Halley. Their properties (densities, atomic composition) are compared with relevant observations from lunar microcraters and in-situ experiments. At 1 AU in the eliptic, 2/3 of the dust grains are normal density particles, presumably of asteroidal origin and irregularly shaped, while the remaining 1/3 are low density particles, presumably of cometary origin, but due to solar irradiation in a processed state (corresponding to “Brownlee”-particles). Beyond the asteroidal belt only black cometary dust grains are observed which have recently been released from comet nuclei orbiting on highly eccentric trajectories.

scholarly journals Statistical test of the distribution of perihelion points and its implication for cometary origin

1985 ◽  
Vol 83 ◽  
pp. 11-17
Author(s):  
S. Yabushita
Keyword(s):  
Selection Effect ◽  
Statistical Test ◽  
Oort Cloud ◽  
Long Period ◽  
The Asymmetry ◽  
South Asymmetry ◽  
Cometary Origin

AbstractThe distribution of perihelion points of long-period comets is known to cluster towards the solar apex, and some authors ascribe it to north-south asymmetry in the distribution of observers. Validity or otherwise of this alleged selection effect is tested by randomly picking up the same number of perihelia in the southern (δ < 0) as those in the northern (δ > 0) hemisphere. It is shown that the observed clustering cannot be ascribed to the asymmetry of observers. Further, 67 comets which are new in Oort’s sense are tested similary. The character of their distribution is similar to that of all the known comets. It appears difficult to interpret the clustering in terms of a recent stellar disturbance of the Oort cloud.

scholarly journals End Products of Cometary Evolution: Cometary Origin of Earth-Crossing Bodies of Asteroidal Appearance

1989 ◽  
Vol 116 (1) ◽  
pp. 537-556 ◽  
Author(s):  
G.W. Wetherill
Keyword(s):  
Time Scale ◽  
Large Fraction ◽  
Volatile Component ◽  
Cometary Nucleus ◽  
Short Period ◽  
Deep Earth ◽  
Dynamical Time ◽  
Time Required ◽  
Almost All ◽  
Cometary Origin

AbstractBecause there is no necessary connection between the time required to remove the volatile component of a cometary nucleus by solar heating (physical lifetime) and the dynamical lifetime of a comet, it is possible that a comet may evolve into an observable object of asteroidal appearance. Almost all comets have dynamical lifetimes much shorter than their physical lifetimes and in these cases complete loss of volatiles will not occur. Mechanisms do exist, however, whereby a small but significant fraction of comets will have longer dynamical lifetimes, permitting them to evolve first into Jupiter-family short period comets and then into comets with relatively safe decoupled orbits interior to Jupiter’s orbit. Observed Jupiter-family objects of asteroidal appearance (e.g., 1983SA) are much more likely to be of cometary rather than asteroidal origin. “Decoupling” is facilitated by several mechanisms: perturbations by the terrestrial planets, perturbations by Jupiter and the other giant planets (including resonant perturbations) and non-gravitational orbital changes caused by the loss of gas and dust from the comet. The dynamical time scale for decoupling is probably 105–106 years and almost all decoupled comets are likely to be of asteroidal appearance. Once decoupled, the orbits of the resulting Apollo-Amor objects will evolve on a longer (107–108 year) time scale, and the orbital evidence for these objects having originally been comets rather than asteroids will nearly disappear. Statistically, however, a large fraction of the bodies in deep Earth-crossing orbits with semi-major axes ≳ 2.2 AU are likely to be cometary objects in orbits that have not yet diffused into the steady state distribution. For plausible values of the relevant parameters, estimates can be made of the number of cometary Apollo-Amor “asteroids,” the observed number of Earthcrossing active and inactive short period comets, and the production rate of short period comets. These estimates are compatible with other theoretical and observational inferences that suggest the presence of a significant population of Apollo objects that formerly were active comets.

Possible cometary origin of heavy noble gases in the atmospheres of Venus, Earth and Mars

Nature ◽  
1992 ◽  
Vol 358 (6381) ◽  
pp. 43-46 ◽  
Author(s):  
Tobias Owen ◽  
Akiva Bar-Nun ◽  
Idit Kleinfeld
Keyword(s):  
Noble Gases ◽  
Cometary Origin

scholarly journals Reply to comment by Fries on “Cometary origin of atmospheric methane variations on Mars unlikely”

2017 ◽  
Vol 122 (4) ◽  
pp. 787-788
Author(s):  
M. Roos-Serote ◽  
S. K. Atreya ◽  
C. R. Webster ◽  
P. R. Mahaffy
Keyword(s):  
Atmospheric Methane ◽  
Cometary Origin

On the implausibility of a cometary origin for most Apollo-Amor asteroids

Icarus ◽  
1981 ◽  
Vol 47 (3) ◽  
pp. 487-491 ◽  
Author(s):  
B.J. Levin ◽  
A.N. Simonenko
Keyword(s):  
Cometary Origin
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