# On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets (Version 2, Revised)

**3rd round review**Read review reports

Reviewer 1 Yvan Dutil independant researcher | Reviewer 2 Dragos G Zaharescu Georgia Institute of Technology | Reviewer 3 | |
---|---|---|---|

Version 1 Original |
Not approved
Authors' response |
Approved with revisions
Authors' response |
Reviewer inviting |

Version 2 Revised |
Not approved
Authors' response |
Approved with revisions
Authors' response |
Reviewer inviting |

Version 3 Revised |
Not approved | Reviewer invited | Reviewer inviting |

Published: 19 October 2019

DOI: 10.3390/sci1030061

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Version 2, Revised

Published: 9 August 2019

DOI: 10.3390/sci1020047

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Version 1, Original

Published: 15 July 2019

DOI: 10.3390/sci1020040

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are seen as important vehicles for the exchange of potential (bio)material within our solar system as well

as between stellar systems in our Galaxy. Accordingly, this requires estimates of the impact probabilities

for different source populations of projectiles, including for intergalactic meteor particles which have

received relatively little attention since considered as rare events (discrete occurrences that are statistically

improbable due to their very infrequent appearance). We employ the simple but yet comprehensive

model of intergalactic microprojectile capture by the gravity of exoplanets which enables us to estimate

the map of collisional probabilities for an available sample of exoplanets in habitable zones around host

stars. The model includes a dynamical description of the capture adopted from Mautner model of

interstellar exchange of microparticles and changed for our purposes. We use statistical and information

metrics to calculate probability map of intergalactic meteorite particle capture. Moreover, by calculating

the entropy index map we measure the concentration of these rare events. We further adopted a model

from immigration theory, to show that the transient distribution of birth/death/immigration of material

for the simplest case has a high value. View Full-Text

**MDPI and ACS Style**

Kovacevic, A.B. On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets. *Sci* **2019**, *1*, 47.

## Review Reports

### Reviewer 1

**Yvan Dutil**|

*Not approved*

independant researcher

To the editor,

I have read this paper carefully, before submitting this comment.

First, I observe that the expression “Mautner-Type” is not common in English and should not be used in the title.

Second, I shall note than gravitation focusing is irrelevant at intergalactic speed. While, this is stated in the third paragraph of the section 2.3.2, this also means that the whole section should be rewritten accordingly.

Third, the whole statistical analysis is based on the false premise that the know population of exoplanets in the habitable zone is representative of the reality, which is not at all. Indeed, the list used by the authors to build their probability distribution comes mostly from the Kepler space mission. The planetary size and especially the distance distribution observed are a consequence of the observational technique used by this mission and not the true spatial distribution of exoplanets. For example, the increase of the planetary radius with distance is a direct consequence of the observational method and has no astrophysical basis. Hence, the whole paper is fundamentally flawed by using this distribution.

The probability values have no unit. Is it per particle encounter or per year? In the second case, the reported observation of a collision of an IMP with Earth is very unlikely to be true.

The whole discussion should be brought in the introduction section, since it does very little to discuss the results of the paper itself. The whole section “Some Parallels with Biological Immigration Models” is irrelevant to the paper topic.

I shall also point out that the distance to the Earth is not the same thing as the distance to the centre of the Galaxy. The Earth being at about 8,000 pc from the galactic centre. Hence distance to Earth has no physical relevance and the conclusion that “The clustering is increasing toward the inner region of Galaxy.” is fundamentally false.

While the statistical methodology might be appropriate, the fundamental assumptions are flawed. The whole paper would have to be reworked to make it physically correct. Hence, I would recommend rejecting this paper.

### Response to Reviewer 1

Sent on 13 Aug 2020 by**Andjelka Kovacevic**

### Reviewer 2

**Dragos G Zaharescu**|

*Approved with revisions*

Georgia Institute of Technology

The topic and paper is very interesting, relevant, and overall it was an exciting read.

Except for few grammatical errors, the manuscript is well written, and easy to read by someone with general math training.

The only major concerns I have are: (i) some of the more complex mathematical formulas have to be better explained in text, to help readers from different fields better follow the logic; (ii) the last sections (Parallel with...) needs better connection with the process addressed in the rest of the paper (parallel should not be taken in its mathematical sense); and (iii) conclusions also have to be rewritten. They are currently written more of a summary list rather than conclusive remarks.

I provide line-by-line comments throughout the PDF, that hopefully will help clarify aspects mentioned above.

Other than that, I greatly appreciate the author's imagination and effort to share it.

### Response to Reviewer 2

Sent on 13 Aug 2020 by**Andjelka Kovacevic**