The Kruger 60 Star System may be the Origin of Interstellar Comet C/2019 Q4 Borisova

Kruger 60 -- a plausible home system of the interstellar comet C/2019 Q4

Authors:

Dybczyński et al

Abstract:

An interstellar comet C/2019 Q4 was discovered on August 30 by an amateur astronomer Gennady Borisov at MARGOT observatory (Crimea). One of the obvious questions is where does this object come from. Taking an orbit obtained by Nakano and published by MPC in CBET 4670 we numerically integrated the motion of C/2019 Q4, the sun and 647 stars or stellar systems from our list of potential stellar perturbers of cometary motion. As a result we obtained that 1 Myr ago C/2019 Q4 passed double star Kruger 60 at a small distance of 1.74 pc having an extremely small relative velocity of 3.43 km/s. Almost the same results were obtained from our own orbital solutions.

Is Oumuamua Really a Comet?

The first-known visitor from outside the Solar System, an object dubbed ‘Oumuamua, is an icy comet rather than a rocky asteroid. New measurements help to confirm early guesses as to the composition of the interstellar interloper, and could also aid researchers in their hunt for similar objects in our Solar System.

Careful observations of ‘Oumuamua’s orbit showed that as the object flew through space, something continually nudged it a tiny bit farther from the Sun than expected. That something was probably ice that warmed up and sprayed gas into space. This process is characteristic of a comet, rather than an asteroid, even though ‘Oumuamua never displayed the glorious tail of gas and dust that accompanies most comets.

“It’s an unusual comet, and that’s pretty exciting,” says Karen Meech, an astronomer at the University of Hawaii in Honolulu. She and her colleagues, led by astronomer Marco Micheli of the European Space Agency in Frascati, Italy, report the discovery on 27 June in Nature.

link.

paper link.

Cometary sputtering of the Martian atmosphere during the Siding Spring encounter

Cometary sputtering of the Martian atmosphere during the Siding Spring encounter

Authors:

Wang et al

Abstract:

With the approach of the close encounter of comet Siding Spring with Mars, possible influences on the Martian atmosphere from the cometary coma are being explored. Here we describe the non-thermal atmospheric loss due to atmospheric sputtering produced by the impact of the coma material. We use an atmospheric sputtering model to simulate the effect of the incident neutral O and the pickup O+,+, produced by photodissociation of water and its products. With the relatively large encounter speed of 56 km/s at a close flyby altitude of ∼130,000 km, the sputtering escape rates from the coma can reach 2–3 times the incident gas fluxes. Thus, the passing of the cometary coma will lead to removal of Martian atmosphere instead of mass loading. If the cometary outgassing rate reaches 10View the MathML source28s−1, the sputtering from the extended coma could remove about 10 tons of Martian gases and deposit about 1 ton of external cometary material into the atmosphere during the one hour encounter. This implies that the cometary sputtering may have played a non-negligible role in Mars atmospheric evolution when this kind of cometary encounter may occur frequently in early Martian epochs.

Impacts by Comets and Asteroids Since the Noachian Probably NOT the Cause of Martian Atmospheric Loss

Scenarios of atmospheric mass evolution on Mars influenced by asteroid and comet impacts since the late Noachian

Authors:

Pham et al

Abstract:

Early in its history, Mars probably had a denser atmosphere and higher surface temperatures to sustain the presence of stable liquid water or saline solution at the surface. Impacts by asteroids and comets could affect the atmospheric evolution of a planet, by removing part of its atmosphere and by delivering into it material and volatiles. In this study we investigate the atmospheric loss and delivery of volatiles between the end of the Noachian and present, with the help of a semi-analytic model. Our results suggest that impacts alone can hardly remove a significant amount of atmospheric mass over this period. Contribution of additional factors such as outgassing and non-thermal escape processes can not explain neither the presence of surface pressure larger than few hundreds of mbars 3.9 Gyr ago, unless parameter values outside of their expected range are considered. Based on extreme case scenarios, maximum surface pressures at the end of the Noachian, could be as much as 0.25 bar or 1.9 bar, with and without CO2 storage into carbonate reservoirs, respectively.

Good Grief: Comets and Asteroids Brought 15N Enriched Ammonia to Earth?!

THE PATH OF REDUCED NITROGEN TOWARD EARLY EARTH: THE COSMIC TRAIL AND ITS SOLAR SHORTCUTS

Authors:

Pizzarello et al

Abstract:

Large isotopic anomalies are found in meteoritic insoluble organic materials (IOMs) and, for nitrogen, show 15N-excesses up to ${\delta }^{15}$N ~ 5000‰. These 15N-enrichments are commonly ascribed to presolar origins, but the attribution seems contradicted by available data on N-isotopes' cosmic distribution. We report here that 15N hotspots in several IOMs are reduced by hydrothermal treatment and their loss correlates with 15N values of ammonia released upon treatment. Because released ammonia's 15N-enrichments also relate with meteorites' mineralogy, i.e., asteroidal processes, and no current models offer plausible explanations for the finding, we account for our data with a novel scenario whereby 15N-enriched ammonia produced in the solar nebula is incorporated by carbonaceous materials and delivered to early Earth by comets and meteorites. The proposal also implies that abundant reduced nitrogen, a required element in origins of life theories, could reach our nascent planet and other planetary systems affecting their habitability.

Academic Bun Fight: the Pleistocene/Holocene Boundary and the Younger Dryas Impact Hypothesis

Bayesian chronological analyses consistent with synchronous age of 12,835–12,735 Cal B.P. for Younger Dryas boundary on four continents

Authors:

Kennett et al

Abstract:

The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature minerals and melt glass, nanodiamonds, carbon spherules, aciniform carbon, platinum, and osmium. Bayesian chronological modeling was applied to 354 dates from 23 stratigraphic sections in 12 countries on four continents to establish a modeled YDB age range for this event of 12,835–12,735 Cal B.P. at 95% probability. This range overlaps that of a peak in extraterrestrial platinum in the Greenland Ice Sheet and of the earliest age of the Younger Dryas climate episode in six proxy records, suggesting a causal connection between the YDB impact event and the Younger Dryas. Two statistical tests indicate that both modeled and unmodeled ages in the 30 records are consistent with synchronous deposition of the YDB layer within the limits of dating uncertainty (∼100 y). The widespread distribution of the YDB layer suggests that it may serve as a datum layer.

That was really bad science

Problematic dating of claimed Younger Dryas boundary impact proxies

Author:

Holliday

Extract:

The PNAS paper by Kennett et al. (1) uses statistical methods in an attempt to improve the geochronological control for purported Younger Dryas boundary (YDB) impact proxies. The underpinning data for these analyses are problematic, however, as discussed by Meltzer et al. (2) and Holliday et al. (3). Several examples illustrate the problems. At Barber Creek the YDB zone is at ∼100 cm below the surface, but in situ wood charcoal dated to 10,500 ± 50 14C y B.P. (∼12.5 k cal yrs) is documented below 100 cm (3). The large SD for the modeled age of the YDB here (1) (12,865 ± 535 cal yrs) easily accommodates the high-precision date on the charcoal from below the spherule zone. At Blackville the sediments dated by optically stimulated luminescence are mixed and thus the dates cannot be considered reliable (3). The supposed impact proxies at Bull Creek are from 307- to 312-cm depth (3). The radiocarbon date of ∼12,960 cal yrs is from 298 to 307 cm and is a bulk sample on soil organic matter, thus representing a mean residence time for the soil carbon. Impact proxies are, therefore, older than ∼12,960 y by some unknown amount; they are also found in abundance in strata less than 3,000 y old. The Usselo soil in northwest Europe spans ∼1,400 y based on ∼50 radiocarbon ages, dating primarily to the Allerød and into the YD (2).

Thbbbbbppppt:

Reply to Holliday and Boslough et al.: Synchroneity of widespread Bayesian-modeled ages supports Younger Dryas impact hypothesis

Authors:

Kennett et al

Extract:

Holliday (1) rejects age-depth models for the Younger Dryas boundary layer (YDB) in Kennett et al. (2), claiming that they are incorrect for several reasons, including age reversals, high age uncertainties, and use of optically stimulated luminescence (OSL) dating. These same claims previously were presented in Meltzer et al. (3) and were discussed and refuted in Kennett et al. (2). These criticisms apply to nearly all dated archaeological and geological sequences, including the Odessa meteorite impact crater, where paradoxically, Holliday et al. (4) modeled an impact age using OSL dating (greater than 70% of dates used) with large uncertainties (to greater than 6,000 y) and age reversals (greatre than 40% of dates are reversals). Thus, Holliday (1) argues against a practice that he and many other researchers have used and continue to use today. In an ideal world, all dates would be in perfect chronological order with high accuracy and certainty, but such scenarios are rarely possible (2). It is because of such dating difficulties that Bayesian analysis is a powerful chronological tool, and is rapidly becoming the archaeological standard.

Earth did NOT get its Water From Comets and Carbonaceous Chondrite Asteroids

In the new study, the researchers report the hydrogen isotope ratios of water trapped in glassy inclusions inside the basalts. The results, published online today in Science, reveal that the inclusions have a much lighter isotopic signature than does the ocean, suggesting that the composition of seawater has indeed evolved over time. Although scientists were aware of processes that could cause an isotopic shift in surface waters, Hallis says, “until we made our measurements, we didn’t know whether that would be a measureable difference or not.”

The new data suggest that the difference is vast. And Hallis suspects that the deepest, most primitive material in the mantle should have an even lighter isotopic composition than the inclusions her team measured. That’s because the rising magma that produced the lavas probably mixed with upper mantle rocks, which have been contaminated with isotopically heavy surface water that got dragged down by subducting slabs of tectonic plates.

So what does all this mean for the origin of Earth’s water? For one, the new data throw a wrench in the conventional story that carbonaceous chondrites—a water-rich variety of asteroid—delivered water to an initially dry Earth after its formation. That scenario has been bolstered by similarities in the isotopic signatures of the asteroids and seawater. But the chondrite signatures are too heavy to explain the deep Earth samples, Hallis says. “The carbonaceous chondrites don’t really work.”

link.

Finding the Comets Knocked Into the Inner Solar System by Past StellarEncounters

Finding the imprints of stellar encounters in long-period comets

Authors:

Feng et al

Abstract:

The Solar system's Oort cloud can be perturbed by the Galactic tide and by individual passing stars. These perturbations can inject Oort cloud objects into the inner parts of the Solar system, where they may be observed as the long-period comets (periods longer than 200 yr). Using dynamical simulations of the Oort cloud under the perturbing effects of the tide and 61 known stellar encounters, we investigate the link between long-period comets and encounters. We find that past encounters were responsible for injecting at least 5 per cent of the currently known long-period comets. This is a lower limit due to the incompleteness of known encounters. Although the Galactic tide seems to play the dominant role in producing the observed long-period comets, the non-uniform longitude distribution of the cometary perihelia suggests the existence of strong – but as yet unidentified – stellar encounters or other impulses. The strongest individual future and past encounters are probably HIP 89825 (Gliese 710) and HIP 14473, which contribute at most 8 and 6 per cent to the total flux of long-period comets, respectively. Our results show that the strength of an encounter can be approximated well by a simple proxy, which will be convenient for quickly identifying significant encounters in large data sets. Our analysis also indicates a smaller population of the Oort cloud than is usually assumed, which would bring the mass of the solar nebula into line with planet formation theories.

The JPL's Hedgehog Bots for Exploring Asteroids and Comets

As demonstrated by the bumpy landing of ESA's Philae lander on comet 67P/Churyumov–Gerasimenko, exploring comets, asteroids, and small moons can be difficult due to their low gravity. Not only can landing on one be like trying to alight on a trampoline, but roving around their surfaces is next to impossible because the negligible gravity offers practically no traction. To overcome this, a team of engineers is developing Hedgehog, a completely symmetrical robot rover for low-gravity exploration that moves by hopping.

A joint project by NASA's Jet Propulsion Laboratory (JPL), Stanford University, and MIT, the Hedgehog robot gets around these limitations with an unusual form of locomotion that allows it to hop, tumble, skip, and even launch itself with artificial "tornadoes." Essentially a cube with horns or spikes on each corner, it has no right way up and every face is identical, so it doesn't matter how it lands. In addition, the cube shape makes it easy to pack economically in a spacecraft.

link.

How to Land on a Comet

Wow

YAGUMET STRIKE! Paper Attempts to Link Mass Extinctions & Giant Comet Impacts

Giant comets and mass extinctions of life

Author:

Napier

Abstract:

I find evidence for clustering in age of well-dated impact craters over the last 500 Myr. At least nine impact episodes are identified, with durations whose upper limits are set by the dating accuracy of the craters. Their amplitudes and frequency are inconsistent with an origin in asteroid breakups or Oort cloud disturbances, but are consistent with the arrival and disintegration in near-Earth orbits of rare, giant comets, mainly in transit from the Centaur population into the Jupiter family and Encke regions. About 1 in 10 Centaurs in Chiron-like orbits enter Earth-crossing epochs, usually repeatedly, each such epoch being generally of a few thousand years' duration. On time-scales of geological interest, debris from their breakup may increase the mass of the near-Earth interplanetary environment by two or three orders of magnitude, yielding repeated episodes of bombardment and stratospheric dusting. I find a strong correlation between these bombardment episodes and major biostratigraphic and geological boundaries, and propose that episodes of extinction are most effectively driven by prolonged encounters with meteoroid streams during bombardment episodes. Possible mechanisms are discussed.

Please take note of my Yet Another Grand Unified Mass Extinction Theory (YAGUMETS) and Stop Dreaming posts.

tl;dr: the evidence from the mass extinction must fit the perpetrator and each has its own distinctive fingerprints with the example of the Permian Extinction and KT/K-Pg Extinction (dino killer) as being very different.

Wait! There Still MIGHT be Something in the Kuiper Belt

Flipping minor bodies: what comet 96P/Machholz 1 can tell us about the orbital evolution of extreme trans-Neptunian objects and the production of near-Earth objects on retrograde orbits

Authors:

de la Fuente Marcos et al

Abstract:

Nearly all known extreme trans-Neptunian objects (ETNOs) have argument of perihelion close to 0°. An existing observational bias strongly favours the detection of ETNOs with arguments of perihelion close to 0° and 180° yet no objects have been found at 180°. No plausible explanation has been offered so far to account for this unusual pattern. Here, we study the dynamical evolution of comet 96P/Machholz 1, a bizarre near-Earth object (NEO) that may provide the key to explain the puzzling clustering of orbits around argument of perihelion close to 0° recently found for the population of ETNOs. Comet 96P/Machholz 1 is currently locked in a Kozai resonance with Jupiter such that the value of its argument of perihelion is always close to 0° at its shortest possible perihelion (highest eccentricity and lowest inclination) and about 180° near its shortest aphelion (longest perihelion distance, lowest eccentricity and highest inclination). If this object is a dynamical analogue (albeit limited) of the known ETNOs, this implies that massive perturbers must keep them confined in orbital parameter space. Besides, its future dynamical evolution displays orbital flips when its eccentricity is excited to a high value and its orbit turns over by nearly 180°, rolling over its major axis. This unusual behaviour, that is preserved when post-Newtonian terms are included in the numerical integrations, may also help understand the production of NEOs on retrograde orbits.

bad astronomer expresses caution.

Wild Bounce at comet Churyumov-Gerasimenko

Sudbury Crater in Canada Confirmed to be Orosirian/Statherian Paleoproterozoic Cometary Impact

On the track of the elusive sudbury impact: geochemical evidence for a chondrite or comet bolide

Authors:

Petrus et al

Abstract:

Siderophile and lithophile trace element data for 69 samples from the Sudbury impact crater fill (Onaping Formation) and quartz diorite offset dikes help constrain the sources of the established moderately elevated platinum group element signature associated with the impact structure. The siderophile element distribution of the crater fill requires contributions from bulk continental crust, mafic rocks and a chondritic component. A mantle component is absent, but the involvement of mid to lower crust is implied. After considering post-impact hydrothermal alteration, melt heterogeneity, and mafic target admixture, the projectile elemental ratios were determined on a more robust data subset. Chondrite discrimination diagrams of these ratios identify an ordinary or enstatite chondrite as the most probable source of meteoritic material in the Sudbury crater fill. However, the relative and absolute siderophile element distributions within the impact structure as well as bolide size models are congruent with the bolide being a comet that had a chondritic refractory component.

Trans-Neptunian Objects Close to the 2:5 and 1:3 Orbital Resonance With Neptune

Dynamical formation of detached trans-Neptunian objects close to the 2:5 and 1:3 mean motion resonances with Neptune

Authors:

Brasil et al

Abstract:

Through a semi-analytic approach of the Kozai resonance inside an MMR, we show phase diagrams (e,{\omega}) that suggest the possibility of a scattered particle, after being captured in an MMR with Neptune, to become a detached object. We ran several numerical integrations with thousands of particles perturbed by the four major planets, and there are cases with and without Neptune's residual migration. These were developed to check the semi-analytic approach and to better understand the dynamical mechanisms that produce the detached objects close to an MMR. The numerical simulations with and without a residual migration for Neptune stress the importance of a particular resonance mode, which we name the hibernating mode, on the formation of fossilized detached objects close to MMRs. When considering Neptune's residual migration we are able to show the formation of detached orbits. These objects are fossilized and cannot be trapped in the MMRs again. We find a ratio of the number of fossilized objects with moderate perihelion distance (35 less than q less than 40 au) to the number of objects with high perihelion distance (q greater than 40 au) as 3.0/1 for objects close to the 2:5, and 1.7/1 for objects close to the 1:3 resonance. We estimate that the two fossilized population have a total mass between 0.1 and 0.3 Pluto's mass.

26 of 29 Sites Cited for "Supporting" Younger Dryas Impact are NOT From the Younger Dryas

Most supposed impact indicators at 29 sites are too old or too young to be remnants of an ancient comet that proponents claim sparked climate change at the end of the Ice Age, killed America's earliest people and caused a mass animal extinction

Controversy over what sparked the Younger Dryas, a brief return to near glacial conditions at the end of the Ice Age, includes a theory that it was caused by a comet hitting the Earth.

As proof, proponents point to sediments containing deposits they believe could result only from a cosmic impact.

Now a new study disproves that theory, said archaeologist David Meltzer, Southern Methodist University, Dallas. Meltzer is lead author on the study and an expert in the Clovis culture, the peoples who lived in North America at the end of the Ice Age.

Meltzer's research team found that nearly all sediment layers purported to be from the Ice Age at 29 sites in North America and on three other continents are actually either much younger or much older.

Scientists agree that the brief episode at the end of the Ice Age — officially known as the Younger Dryas for a flower that flourished at that time — sparked widespread cooling of the Earth 12,800 years ago and that this cool period lasted for 1,000 years. But theories about the cause of this abrupt climate change are numerous. They range from changes in ocean circulation patterns caused by glacial meltwater entering the ocean to the cosmic-impact theory.

The cosmic-impact theory is said to be supported by the presence of geological indicators that are extraterrestrial in origin. However a review of the dating of the sediments at the 29 sites reported to have such indicators proves the cosmic-impact theory false, said Meltzer.

Meltzer and his co-authors found that only three of 29 sites commonly referenced to support the cosmic-impact theory actually date to the window of time for the Ice Age.

The findings, "Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago," were reported May 12, 2014, in the Proceedings of the National Academy of Sciences.

link.

How Much Dust Will Siding Spring Pepper Mars With?

Delivery of dust grains from comet C/2013 A1 (Siding Spring) to Mars

Authors:

Tricarico et al

Abstract:

Comet C/2013 A1 (Siding Spring) will have a close encounter with Mars on October 19, 2014. We model the dynamical evolution of dust grains from the time of their ejection from the comet nucleus to the Mars close encounter, and determine the flux at Mars. Constraints on the ejection velocity from Hubble Space Telescope observations indicate that the bulk of the grains will likely miss Mars, although it is possible that a few-percent of grains with higher velocities will reach Mars, peaking approximately 90--100 minutes after the close approach of the nucleus, and consisting mostly of millimeter-radius grains ejected from the comet nucleus at a heliocentric distance of approximately 9~AU or larger. At higher velocities, younger grains from sub-millimeter to several millimeter can reach Mars too, although an even smaller fraction of grains is expected have these velocities, with negligible effect on the peak timing. Using NEOWISE observations of the comet, we can estimate that the maximum fluence will be of the order of 10−7 grains/m2. We include a detailed analysis of how the expected fluence depends on the grain density, ejection velocity, and size-frequency distribution, to account for current model uncertainties and in preparation of possible refined model values in the near future.

How Fast was the Onset of the Paleocene-Eocene Thermal Maximum? Was a Comet to Blame?!?!

A Comet Caused the PETM!

Evidence for a rapid release of carbon at the Paleocene-Eocene thermal maximum

Authors:

Wright et al

Abstract:

The Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE) are often touted as the best geologic analog for the current anthropogenic rise in pCO2. However, a causal mechanism for the PETM CIE remains unidentified because of large uncertainties in the duration of the CIE’s onset. Here, we report on a sequence of rhythmic sedimentary couplets comprising the Paleocene/Eocene Marlboro Clay (Salisbury Embayment). These couplets have corresponding δ18O cycles that imply a climatic origin. Seasonal insolation is the only regular climate cycle that can plausibly account for δ18O amplitudes and layer counts. High-resolution stable isotope records show 3.5‰ δ13C decrease over 13 couplets defining the CIE onset, which requires a large, instantaneous release of 13C-depleted carbon. During the CIE, a clear δ13C gradient developed on the shelf with the largest excursions in shallowest waters, indicating atmospheric δ13C decreased by ∼20‰. Our observations and revised release rate are consistent with an atmospheric perturbation of 3,000-gigatons of carbon (GtC).

No! It Did NOT!

Onset of carbon isotope excursion at the Paleocene-Eocene thermal maximum took millennia, not 13 years

Authors:

Zeebee et al

Abstract:

The Paleocene-Eocene thermal maximum (PETM) may represent the best paleo-analog for rapid and massive carbon release to the ocean and atmosphere. Thus, constraining the carbon release rate at its onset is critical. Wright and Schaller (1) use records from apparently rhythmically layered shelf sediments to argue that the layering is annual and that the onset of the carbon isotope excursion (CIE, fingerprint for carbon release) in the surface ocean was complete in 13 y. Using basic carbon cycle and climate considerations, we show this is not feasible. In fact, Wright and Schaller’s isotope records indicate that the CIE onset took at least several millennia. This finding rules out a cometary origin of the carbon release.

Yes, it did!

Reply to Pearson and Nicholas, Stassen et al., and Zeebe et al.: Teasing out the missing piece of the PETM puzzle

Authors:

Wright et al

Abstract:

Understanding the Paleocene-Eocene Thermal Maximum (PETM) critically depends on knowing the rate at which the perturbation carbon was released. In our report (1) we argue that the layered Marlboro Clay may provide this important constraint. Our strongest evidence in support of the rapid release of carbon at the onset of the PETM is the differential response of the %CaCO3 and δ13C in the Millville core. The sharp %CaCO3 decrease occurred over 4 mm, compared with the δ13C decrease over an interval of 25 cm (figure 3 in ref. 1). Temporal differences are predicted by a rapid (instantaneous) release of light carbon, which would lower the surface ocean Graphic in a matter of months, in contrast to the carbon isotopic equilibrium exchange, which occurs on the scale of a decade (2) and can only be recorded in a core with a high sedimentation rates (1). Based on the rhythmic bedding in the Marlboro Clay, we argue that the drop in %CaCO3 occurred in less than a year and the δ13C equilibrium was on the order of a decade.

My guess is probably not given all we know of the PETM.

New Paper Claims Chicxulub Impactor was a Comet

Assessments of the energy, mass and size of the Chicxulub Impactor

Authors:

Durand-Manterola et al

Abstract:

In 1980, Alvarez and colleagues proposed that, in the transition from the Cretaceous to Paleogene, a large impactor collided with Earth being the cause of the mass extinction occurred at the limit K / Pg. In 1980 there was no known impact structure, which could be responsible for this extinction. It was not until 1991 that an international group of researchers proposed that a circular structure between 180 and 200 km, buried under Tertiary deposits in the Yucatan Peninsula in Mexico, was the crater formed by the impact proposed by the group of Alvarez (Hildebrand et al., 1991). It is very probable that an impact of this magnitude have had large effects on the surface and in the environment. To study these effects, it is necessary to estimate the characteristics that the impactor had. The literature often mentions the nature of the impactor, and has been proposed both an asteroid and a comet, and even a comet shower that produced periodic extinctions. However, the physical parameters of the impactor are not limited, so the aim of this study is to estimate the most relevant features of this one such as the size, mass and kinetic energy. We found that the kinetic energy of the impactor is in the range from 1.3e24 J to 5.8e25 J. The mass is in the range of 1.0e15 kg to 4.6e17 kg. Finally, the diameter of the object is in the range of 10.6 km to 80.9 km. Based on the mass of the impactor and iridium abundance in different types of meteorites, we calculate the concentration of iridium, which should be observed in the K/Pg layer. When compared with the measurements, we concluded that the best estimation is that the impactor was a comet.