Peer review of: The operational environment and rotational acceleration of asteroid (101955) Bennu from OSIRIS (2022)

Reviewers' comments:  
 
Reviewer #1 (Remarks to the Author):  
 
General remarks: The paper is very interesting and useful for scientists investigating physical 
properties, both the asteroid Bennu and other space bodies that were studied from space missions. 
The all assumptions are spelled out clearly, the methods are described comprehensively and the 
figures and tables are necessary and properly laid out. I have carefully read the manuscript and 
found no substantive comments that would not be allowed to publish it. The paper satisfies a 
subject area of the Journal and may be published after minor revisions.  
 
 
REMARKS  
 
Lines 23-24: You would not write full name of the spacecraft in the abstract. It is better to give the 
full name at the beginning of the paper.  
 
Line 33: Degree in acceleration should be as a superscript.  
 
Line 132: Reference [24] does not relate to the Lommel-Seeliger model. See remark to line 588. It 
should be corrected.  
 
Lines 132-137: Pentilla et al. (Pentilla et al. 2016. Planet. Space Sci. 123, 117-125) using a new 
data set of high-quality magnitude-phase functions of 93 asteroids (Shevchenko et al. 2016. 
Planet. Space Sci. 123, 101-116) re-assessed the two-parameter version of the HG1G2 function 
and introduced a one-parameter version of the phase function that can give a suggestion of the 
asteroids taxonomic group based only on its phase curve. An online tool that implements these 
algorithms is introduced on site: http://www.helsinki.fi/project/psr/HG1G2/. Please, recalculate 
your disk-integrated data using new versions of these functions and insert obtained new 
parameters in the Supplementary Table 2.  
 
Lines 150-156: Shevchenko & Belskaya (Shevchenko & Belskaya 2010, EPSC Abstracts. Vol. 5, 
738) analyzed magnitude-phase functions of 33 dark asteroids pointed out that about 40% of dark 
asteroids displayed wide opposition effect starting at the phase angle 6-7 deg with amplitude of 
0.15- 0.25 mag. Please, take into account this in your analysis.  
 
Line 154: Reference [24] should be changed on [21].  
 
Line 165: Reference [15] should be changed on [13].  
 
Line 168: Reference [14] should be changed on [13].  
 
Line 404: Reference [23] should be changed on [27].  
 
Line 588: There is no reference on Hapke 2012 in the list of references.  
 
Line 601: It is needed to insert a number of reference Lauretta 2019.  
 
Please, insert of your disk-integrated data on the magnitude-phase relation of Bennu in 
supplementary Table for more investigation.  

Reviewer #2 (Remarks to the Author):  
 
This paper treats a quite original data and must be published. It is usuful information for the 
research communities that each result shows the good agreement between the ground-based 
observations/other mission data/several models and the OSIRIS-Rex data.  
 
Comments:  
- Search for Natural Satellites (P.2): The paper indicates the detectable size and the area range 
but it seems not to mention the possibility of the moving objects in front of Bennu or at the back 
of Bennu during the observations; Due to the long-term observation dates, the orbital motion 
would, of course, reveal the existence of the objects.  
- Supplementary Table 1: Phase angle, Distance from Bennu searched etc. have only one value at 
each date. Didn't they change during the "start and end range of search"? Especially, the phase 
angle is correct to three significant figures.  
 
Minor comments:  
- The expression of dates should be uniformed: 12 September 2018 / 2018 Nov. 2 / 2018-Oct-23.  
- You use "approach" with capital "A", such as "Approach phase." A similar expression, for 
example, is "Detailed Survey phase." Do the captial words have special meanings in the mission? 
If so, it is ok.  
- Line 371(Figure 2): 0.24m is expressed as 24 cm in other sections.  
- Line 389/390(Figure 3): The red points is blue? Also black line is purple broken line? My PC 
display/printed papers show different colors from the captions.  
- Line 439: AAM2 should be explained the meaning (the meaning of AAM3 is at Line 515.)  
- Line 480: distances is distance?  
- Line 490: AU is au.  
- Line 497: Do we need "from"?  
- Supplementary Table 2: Each column should insert each unit if they need.  
 
 
 
 
Reviewer #3 (Remarks to the Author):  
 
Paper presents solid but not particularly interesting results on Bennu. I do not see anything wrong 
with this paper but am unsure about its suitability for the journal.