scholarly journals Jupiter’s decisive role in the inner Solar System’s early evolution

2015 ◽  
Vol 112 (14) ◽  
pp. 4214-4217 ◽  
Author(s):  
Konstantin Batygin ◽  
Greg Laughlin
Keyword(s):  
Solar System ◽  
Dynamical Evolution ◽  
Decisive Role ◽  
Terrestrial Planets ◽  
The Sun ◽  
Mean Motion Resonances ◽  
The Earth ◽  
Short Period ◽  
Orbital Periods ◽  
Gas Drag

The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System’s terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter’s inward migration entrained s ≳ 10−100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System’s terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution.

scholarly journals The Origin of Comets

1972 ◽  
Vol 45 ◽  
pp. 401-408 ◽  
Author(s):  
F. L. Whipple
Keyword(s):  
Solar System ◽  
Refractory Material ◽  
Total Mass ◽  
Terrestrial Planets ◽  
The Sun ◽  
The Earth ◽  
Collapsing Cloud

The evolution of the solar system is surveyed, it being presumed that the Sun, Jupiter, and Saturn formed rather quickly and essentially with the composition of the original collapsing cloud of dust and gas. Just as the refractory material of the cloud is considered to have formed into planetesimals, from which the terrestrial planets collected, so is the icy material supposed to have produced comets, or cometesimals, from which Uranus and Neptune (and to some extent Saturn and Jupiter) were built up. The presence of a residual belt of comets beyond the orbit of Neptune is discussed, analysis of possible perturbative effects on P/Halley indicating that the total mass of such a belt at 50 AU from the Sun could not now exceed the mass of the Earth.

scholarly journals Active bodies in the near-Earth region: The tenuous boundary between comets and asteroids

2015 ◽  
Vol 10 (S318) ◽  
pp. 142-143
Author(s):  
Julio A. Fernández ◽  
Andrea Sosa
Keyword(s):  
Dynamical Evolution ◽  
The Other ◽  
General Definition ◽  
The Sun ◽  
Main Belt ◽  
Close Encounters ◽  
The Earth ◽  
Bare Nucleus ◽  
Short Period ◽  
Near Earth Asteroids

AbstractWe analyze the dynamics and activity observed in bodies approaching the Earth (perihelion distancesq< 1.3 au) in short-period orbits (P< 20 yr), which essentially are near-Earth Jupiter Family Comets (NEJFCs) and near-Earth asteroids (NEAs). In the general definition, comets are “active”, i.e. they show some coma, while asteroids are “inactive”, i.e. they only show a bare nucleus. Besides their activity, NEJFCs are distinguished from NEAs by their dynamical evolution: NEJFCs move on unstable orbits subject to frequent close encounters with Jupiter, whereas NEA orbits are much more stable and tend to avoid close encounters with Jupiter. However, some JFCs are found to move on stable, asteroidal-type orbits, so the question arises if these objects are asteroids that have become active, perhaps upon approach to the Sun. In this sense they may be regarded as the counterparts of the main-belt comets (Hsieh & Jewitt 2006). On the other hand, some seemingly inert NEAs move on unstable, comet-type orbits, so the question about what is a comet and what is an asteroid has become increasingly complex.

scholarly journals On the orbital evolution of 2020 AV2, the first asteroid ever observed to go around the Sun inside the orbit of Venus

2020 ◽  
Vol 494 (1) ◽  
pp. L6-L10 ◽  
Author(s):  
C de la Fuente Marcos ◽  
R de la Fuente Marcos
Keyword(s):  
Orbital Evolution ◽  
Gravitational Perturbation ◽  
The Sun ◽  
Moon System ◽  
Resonant Orbit ◽  
The Earth ◽  
Short Period ◽  
Orbital Periods ◽  
Near Earth Objects

ABSTRACT The innermost section of the Solar system has not been extensively studied because minor bodies moving inside Earth’s orbit tend to spend most of their sidereal orbital periods at very low solar elongation, well away from the areas more frequently observed by programs searching for near-Earth objects. The survey carried out from the Zwicky Transient Facility (ZTF) is the first one that has been able to detect multiple asteroids well detached from the direct gravitational perturbation of the Earth–Moon system. ZTF discoveries include 2019 AQ3 and 2019 LF6, two Atiras with the shortest periods among known asteroids. Here, we perform an assessment of the orbital evolution of 2020 AV2, an Atira found by ZTF with a similarly short period but following a path contained entirely within the orbit of Venus. This property makes it the first known member of the elusive Vatira population. Genuine Vatiras, those long-term dynamically stable, are thought to be subjected to the so-called von Zeipel–Lidov–Kozai oscillation that protects them against close encounters with both Mercury and Venus. However, 2020 AV2 appears to be a former Atira that entered the Vatira orbital domain relatively recently. It displays an anticoupled oscillation of the values of eccentricity and inclination, but the value of the argument of perihelion may circulate. Simulations show that 2020 AV2 might reach a 3:2 resonant orbit with Venus in the future, activating the von Zeipel–Lidov–Kozai mechanism, which in turn opens the possibility to the existence of a long-term stable population of Vatiras trapped in this configuration.

Exoplanets, 2003–2013

Daedalus ◽  
2014 ◽  
Vol 143 (4) ◽  
pp. 81-92
Author(s):  
Gáspár Áron Bakos
Keyword(s):  
Solar System ◽  
Aspect Ratio ◽  
Extrasolar Planets ◽  
Large Fraction ◽  
The Sun ◽  
The Moon ◽  
Short Period ◽  
Giordano Bruno ◽  
Formation And Evolution ◽  
Orbital Periods

Cosmologists and philosophers had long suspected that our sun was a star, and that just like the sun, other stars were also orbited by planets. These and similar ideas led to Giordano Bruno being burned at the stake by the Roman Inquisition in 1600. It was not until 1989, however, that the first exoplanet – a planet outside the solar system – was discovered. While the rate of subsequent discoveries was slow, most of these were important milestones in the research on extrasolar planets, such as finding planets around a pulsar (a compact remnant of a collapsed star) and finding Jupiter-mass planets circling their stars on extremely short period orbits (in less than a few Earth-days). But the first decade of our millennium witnessed an explosion in the number of discovered exoplanets. To date, there are close to one thousand confirmed and three thousand candidate exoplanets. We now know that a large fraction of stars have planets, and that these planets show an enormous diversity, with masses ranging from that of the moon (1/100 that of Earth, or 0.01M⊕) to twenty-five times that of Jupiter (25MJ, or approximately 10,000M⊕); orbital periods from less than a day to many years; orbits from circular to wildly eccentric (ellipses with an “eccentricity” parameter of 0.97, corresponding to an aspect ratio of 1:4); and mean densities from 0.1g cm−3 (1/10 of water) to well over 25g cm−3. Some of these planets orbit their stars in the same direction as the star spins, some orbit in the opposite direction or pass over the stellar poles. Observations have been immensely useful in constraining theories of planetary astrophysics, including with regard to the formation and evolution of planets. In this essay, I summarize some of the key results.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

From the Oort cloud to Halley-type comets

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo
Keyword(s):  
Total Population ◽  
Complex Function ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Capture Process ◽  
Influx Rate ◽  
Short Period ◽  
Dynamical Properties ◽  
Orbital Periods ◽  
Probability Of Capture

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods &lt; 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq &lt;2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods &lt; 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

scholarly journals Resonant trans-Neptunian objects as a source of Jupiter-family comets

2006 ◽  
Vol 2 (S236) ◽  
pp. 31-34
Author(s):  
E. L. Kiseleva ◽  
V. V. Emel'yanenko
Keyword(s):  
Solar System ◽  
Dynamical Evolution ◽  
Early History ◽  
Substantial Contribution ◽  
Outer Solar System ◽  
Symplectic Integrator ◽  
Relative Fraction ◽  
Outward Transport ◽  
Short Period ◽  
History Of

AbstractThe dynamical interrelation between resonant trans-Neptunian objects and short-period comets is studied. Initial orbits of resonant objects are based on computations in the model of the outward transport of objects during Neptune's migration in the early history of the outer Solar system. The dynamical evolution of this population is investigated for 4.5 Gyr, using a symplectic integrator. Our calculations show that resonant trans-Neptunian objects give a substantial contribution to the planetary region. We have estimated that the relative fraction of objects captured per year from the 2/3 resonance to Jupiter-family orbits with perihelion distances q<2.5 AU is 0.4×10−10 near the present epoch.

Late Accretion and the Origin of Water on Terrestrial Planets in the Solar System

2021 ◽  
Author(s):  
Cédric Gillmann ◽  
Gregor Golabek ◽  
Sean Raymond ◽  
Paul Tackley ◽  
Maria Schonbachler ◽  
...  
Keyword(s):  
Solar System ◽  
Long Term Evolution ◽  
Terrestrial Planets ◽  
Evolutionary Pathway ◽  
Giant Impact ◽  
The Earth ◽  
Term Evolution ◽  
Surface Liquid ◽  
Venus Atmosphere

&lt;p&gt;Terrestrial planets in the Solar system generally lack surface liquid water. Earth is at odd with this observation and with the idea of the giant Moon-forming impact that should have vaporized any pre-existing water, leaving behind a dry Earth. Given the evidence available, this means that either water was brought back later or the giant impact could not vaporize all the water.&lt;/p&gt;&lt;p&gt;We have looked at Venus for answers. Indeed, it is an example of an active planet that may have followed a radically different evolutionary pathway despite the similar mechanisms at work and probably comparable initial conditions. However, due to the lack of present-day plate tectonics, volatile recycling, and any surface liquid oceans, the evolution of Venus has likely been more straightforward than that of the Earth, making it easier to understand and model over its long term evolution.&lt;/p&gt;&lt;p&gt;Here, we investigate the long-term evolution of Venus using self-consistent numerical models of global thermochemical mantle convection coupled with both an atmospheric evolution model and a late accretion N-body delivery model. We test implications of wet and dry late accretion compositions, using present-day Venus atmosphere measurements. Atmospheric losses are only able to remove a limited amount of water over the history of the planet. We show that late accretion of wet material exceeds this sink. CO&lt;sub&gt;2&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt; contributions serve as additional constraints.&lt;/p&gt;&lt;p&gt;Water-rich asteroids colliding with Venus and releasing their water as vapor cannot explain the composition of Venus atmosphere as we measure it today. It means that the asteroidal material that came to Venus, and thus to Earth, after the giant impact must have been dry (enstatite chondrites), therefore preventing the replenishment of the Earth in water. Because water can obviously be found on our planet today, it means that the water we are now enjoying on Earth has been there since its formation, likely buried deep in the Earth so it could survive the giant impact. This in turn suggests that suggests that planets likely formed with their near-full budget in water, and slowly lost it with time.&lt;/p&gt;

Evolution of Comets into Asteroids?

1971 ◽  
Vol 12 ◽  
pp. 413-421 ◽  
Author(s):  
B.G. Marsden
Keyword(s):  
Solar Radiation ◽  
Solar Nebula ◽  
Oort Cloud ◽  
Original Version ◽  
Terrestrial Planets ◽  
Minor Planets ◽  
The Sun ◽  
Physical Difference ◽  
Short Period ◽  
The One

There has long been speculation as to whether comets evolve into asteroidal objects. On the one hand, in the original version of the Oort (1950) hypothesis, the cometary cloud was supposed to have formed initially from the same material that produced the minor planets; and an obvious corollary was that the main physical difference between comets and minor planets would be that the latter had long since lost their icy surfaces on account of persistent exposure to strong solar radiation (Öpik, 1963). However, following a suggestion by Kuiper (1951), it is now quite widely believed that, whereas the terrestrial planets and minor planets condensed in the inner regions of the primordial solar nebula, icy objects such as comets would have formed more naturally in the outer parts, perhaps even beyond the orbit of Neptune (Cameron, 1962; Whipple, 1964a). Furthermore, recent studies of the evolution of the short-period comets indicate that it is not possible to produce the observed orbital distribution from the Oort cloud, even when multiple encounters with Jupiter are considered (Havnes, 1970). We must now seriously entertain the possibility that most of the short-period orbits evolved directly from low-inclination, low-eccentricity orbits with perihelia initially in the region between, say, the orbits of Saturn and Neptune, and that these comets have never been in the traditional cloud at great distances from the Sun.

scholarly journals Dynamics of Comets

1992 ◽  
Vol 152 ◽  
pp. 255-268 ◽  
Author(s):  
A. Carusi ◽  
G.B. Valsecchi
Keyword(s):  
Molecular Clouds ◽  
Vertical Component ◽  
The Sun ◽  
Giant Molecular Clouds ◽  
Mean Motion Resonances ◽  
Galactic Field ◽  
Mean Motion ◽  
Short Period ◽  
Gravitational Processes

The gravitational processes affecting the dynamics of comets are reviewed. At great distances from the Sun the motion of comets is primarily affected by the vertical component of the galactic field, as well as by encounters with stars and giant molecular clouds. When comets move in the region of the planets, encounters with these can strongly affect their motion. A good fraction of all periodic comets spend some time in temporary libration about mean motion resonances with Jupiter; some comets can be captured by this planet as temporary satellites. Finally, there is a small number of objects with orbital characteristics quite different from those of all other short-period comets.

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