101955 Bennu is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999. It is a potentially hazardous object that is listed on the Sentry Risk Table and tied for the highest cumulative rating on the Palermo Technical Impact Hazard Scale. It has a cumulative 1-in-1,800 chance of impacting Earth between 2178 and 2290 with the greatest risk being on 24 September 2182. It is named after the Bennu, the ancient Egyptian mythological bird associated with the Sun, creation, and rebirth.

101955 Bennu has a mean diameter of 490 m (1,610 ft; 0.30 mi) and has been observed extensively with the Arecibo Observatory planetary radar and the Goldstone Deep Space Network. Bennu was the target of the OSIRIS-REx mission which is intended to return its samples to Earth in 2023 for further study. On 3 December 2018, the OSIRIS-REx spacecraft arrived at Bennu after a two-year journey. It orbited the asteroid and mapped out Bennu's surface in detail, seeking potential sample collection sites. Analysis of the orbits allowed calculation of Bennu's mass and its distribution.

On 18 June 2019, NASA announced that the OSIRIS-REx spacecraft had closed in and captured an image from a distance of 600 metres (2,000 ft) from Bennu's surface. In October 2020, OSIRIS-REx successfully touched down on the surface of Bennu, collected a sample using an extendable arm, secured the sample and prepared for a return trip to Earth. On 10 May 2021, OSIRIS-REx successfully completed its departure from the Bennu asteroid while still carrying the sample of the asteroid rubble.

Astrometric observations between 1999 and 2013 have demonstrated that 101955 Bennu is influenced by the Yarkovsky effect, causing the semimajor axis of its orbit to drift on average by 284±1.5 meters/year. Analysis of the gravitational and thermal effects has given a bulk density of ρ = 1190±13 kg/m3, which is only slightly denser than water. Therefore, the predicted macroporosity is 40±10%, suggesting the interior has a rubble pile structure or even hollows. The estimated mass is (7.329±0.009)×1010 kg.

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  • PorkrollPosadist [he/him, they/them]
    ·
    3 years ago

    Not sure if this is your problem, but the ntfs-3g driver will refuse to mount an NTFS filesystem in read/write mode if a hibernation file is present. Depending on how you try mounting the filesystem, (terminal vs. various gui file managers) the mounting operation may fail without conveying this error message or prompting whether you want to mount it read-only instead. There is a cli option to force mounting in read/write mode (deleting the hibernation file), as well as mounting read-only.

    By default, Windows creates a hibernation file even when you tell it to shut down normally. This allegedly makes it boot faster. There are one or two settings you need to change to make it stop doing this. (I remain convinced it is conspiracy to make dual booting more inconvenient :illuminati: ).

    • ZachWilsonGOAT [he/him]
      ·
      3 years ago

      is there any disadvantage to deleting the hibernation file? would i have to boot into windows to do that or would i be able to do that in Ubuntu? could you at least walk me through on mounting it as read-only? i'm not sure there's anything i really need to back up from that drive but i'd rather be safe than sorry.

      • PorkrollPosadist [he/him, they/them]
        ·
        3 years ago

        If you actually hibernated the machine, you would lose whatever work you hadn't saved in any software which was running. Otherwise, no. It might just take an extra few seconds to boot. The real danger comes from modifying the filesystem without deleting the hibernation file, which is why the driver forbids it.

        If the problem is the presence of a hibernation file, it will tell you in the error message. First, I would try mounting the filesystem on the Ubuntu Live USB from a terminal so you can see any error messages it produces. Try:

        sudo mkdir /mnt/windows
        sudo mount /dev/<windows partition device> /mnt/windows

        If it warns you about a hibernation file, that's likely the problem. If it says nothing about it, there is probably something else wrong (it may give you more information than the GUI though)

        The hibernation file can be deleted from Windows or Ubuntu. On Windows, you would want to disable hibernation. This will delete the hibernation file and prevent the OS from creating a new one until you enable it again. This can be switched off and on in the command line by running:

        powercfg /h off

        to turn it off, and

        powercfg /h on

        to turn it back on. On Ubuntu, you can try telling the driver to remove the hibernation file by running

        sudo mount -t ntfs-3g -o remove_hiberfile /dev/<windows partition device> /mnt/windows

        to attempt deleting the hibernation file and mounting read/write, or

        sudo mount -r /dev/<windows partition device> /mnt/windows

        to attempt mounting it read-only.

        Worst case scenario, you can use a tool like dd to create a backup image of the hard drive so you can attempt to crack it open at your leisure or run various file recovery tools on it. Be careful with dd though because it will happily overwrite any hard drive you tell it to if you're not careful.

        • ZachWilsonGOAT [he/him]
          ·
          3 years ago

          yo, i really appreciate the help

          i failed on the first command lol it hits me with:

          mkdir: cannot create directory ‘/mt/windows’: No such file or directory

            • ZachWilsonGOAT [he/him]
              ·
              3 years ago

              holy shit my bad, im kinda sleepy

              on the 2nd command you mentioned it gives me this:

              mount: /mnt/windows: wrong fs type, bad option, bad superblock on /dev/sda, missing codepage or helper program, or other error.

              i tried mounting both the entire drive and just mounting the partition i want

              • PorkrollPosadist [he/him, they/them]
                ·
                3 years ago

                Mounting the entire hard drive won't work, you need to tell it a partition, so it would be /dev/sda# rather than /dev/sda. I guess we need to explicitly tell it what filesystem type we're using too. Try sudo mount -t ntfs-3g /dev/sda<number> /mnt/windows

                There is a small chance the Ubuntu live USB doesn't even ship the ntfs driver, but I'd be kinda shocked if that were the case. On my machine I don't need to explicitly tell it to use ntfs-3g, but I have found myself in situations in the past (can't remember what the hell I was doing) where I did need to tell it.

                • ZachWilsonGOAT [he/him]
                  ·
                  3 years ago

                  ok, it gave me this

                  NTFS signature is missing.
                  Failed to mount '/dev/sda2': Invalid argument
                  The device '/dev/sda2' doesn't seem to have a valid NTFS.
                  Maybe the wrong device is used? Or the whole disk instead of a
                  partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

                  this is how the disk and the partition show in the Ubuntu 'Disks' program., not sure if that helps or not. i don't know much but it does look odd.

                  • PorkrollPosadist [he/him, they/them]
                    ·
                    3 years ago

                    Fascinating. It looks like you're doing everything right, but that message isn't a great sign.

                    I suppose we should review the facts. The computer boots the Ubuntu LiveUSB, so we can probably toss out the SecureBoot theory. If that wasn't enough, it is capable of detecting the disk and reading the partition table from it. Ubuntu is demonstrably capable of reading the disk, so this isn't the reason it isn't able to mount the filesystem.

                    The ntfs-3g driver is present, so it isn't due to the lack of a driver. The driver is erroring out and saying it doesn't recognize the NTFS signature. This indicates that something is wrong. This is supported by the fact that Windows barely runs, though the fact that Windows runs at all is kind of surprising.

                    As for the root cause, it could be a number of things. I would treat the disk itself with suspicion, but it could also be a power failure at a bad time, an extremely uncommon software bug, cosmic rays, who knows.

                    I've never used it, but there is a tool called ntfsfix which might help. To quote the manual:

                    ntfsfix is a utility that fixes some common NTFS problems. ntfsfix is NOT a Linux version of chkdsk. It only repairs some fundamental NTFS inconsistencies, resets the NTFS journal file and schedules an NTFS consistency check for the first boot into Windows.

                    You may run ntfsfix on an NTFS volume if you think it was damaged by Windows or some other way and it cannot be mounted.

                    I'd give sudo ntfsfix /dev/sda2 a shot, but be aware that this will make changes to the filesystem. I'm sure the tool errs on the side of caution, but from a data forensics best practices standpoint it's best to have a backup image before messing around with it. Anyway, the tool is probably present on the liveUSB already, since it is a part of the ntfs-3g project.

                    After running it, try booting Windows again and see if it can complete the consistency check. Or try mounting the filesystem again.

                    There's also the option of running chkdsk directly on Windows, but that seems like it would be quite a challenge under the circumstances. It could be done though if you have a second Windows computer which you can plug this hard drive into.