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Thread: Another interstellar comet coming in?

  1. #1
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    Exclamation Another interstellar comet coming in?

    Interesting article on a comet with a hyperbolic orbit.

    https://arxiv.org/abs/1908.02666

    Comet C/2018 V1 (Machholz-Fujikawa-Iwamoto): dislodged from the Oort Cloud or coming from interstellar space?
    C. de la Fuente Marcos, R. de la Fuente Marcos (Submitted on 7 Aug 2019)

    The chance discovery of the first interstellar minor body, 1I/2017 U1 (`Oumuamua), indicates that we may have been visited by such objects in the past and that these events may repeat in the future. Unfortunately, minor bodies following nearly parabolic or hyperbolic paths tend to receive little attention: over 3/4 of those known have data-arcs shorter than 30 d and, consistently, rather uncertain orbit determinations. This fact suggests that we may have observed interstellar interlopers in the past, but failed to recognize them as such due to insufficient data. Early identification of promising candidates by using N-body simulations may help in improving this situation, triggering follow-up observations before they leave the Solar system. Here, we use this technique to investigate the pre- and post-perihelion dynamical evolution of the slightly hyperbolic comet C/2018 V1 (Machholz-Fujikawa-Iwamoto) to understand its origin and relevance within the context of known parabolic and hyperbolic minor bodies. Based on the available data, our calculations suggest that although C/2018 V1 may be a former member of the Oort Cloud, an origin beyond the Solar system cannot be excluded. If extrasolar, it might have entered the Solar system from interstellar space at low relative velocity with respect to the Sun. The practical feasibility of this alternative scenario has been assessed within the kinematic context of the stellar neighbourhood of the Sun, using data from Gaia DR2, and two robust solar sibling candidates have been identified. Our results suggest that comets coming from interstellar space at low heliocentric velocities may not be rare.

  2. #2
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    It would be nice to see its trajectory on a map that shows the locations of our assets in space--just on a chance we can get pix.

  3. #3
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    A new candidate for the "interstellar" designation has been announced: see Astronomer's Telegram #13100:

    http://www.astronomerstelegram.org/?read=13100

    We need more observations to confirm its nature, but it is coming inward toward the Sun and the Earth, so it will become easier to see and measure over the next few months.

  4. #4
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    Quote Originally Posted by publiusr View Post
    It would be nice to see its trajectory on a map that shows the locations of our assets in space--just on a chance we can get pix.
    here you go: https://ssd.jpl.nasa.gov/sbdb.cgi?ss...3639&orb=1#orb (edit: sorry wrong object that is the other possible interstellar object C/2019 Q4, C/2018 V1 is here: https://ssd.jpl.nasa.gov/sbdb.cgi?ss...3590&orb=1#orb)



    The best place to observe anything from is usually Earth since that is where all the really good telescopes are. The only exception is space craft that are observing the body they are orbiting. In this case it looks like C/2019 Q4 will come closer to Mars than Earth by about a factor or two or so. The HiRISE camera is probably the best in Mars vicinity but it has an aperture of "only" 50 cm and lacks many instruments like spectrographs so Hubble and earth based telescopes will be able to gather much better data.

    ETA: For C/2018 V1 I don't think there is anything close with a decent camera.
    Last edited by glappkaeft; 2019-Sep-13 at 05:49 AM.

  5. #5
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    Quote Originally Posted by glappkaeft View Post
    The best place to observe anything from is usually Earth since that is where all the really good telescopes are. The only exception is space craft that are observing the body they are orbiting. In this case it looks like C/2019 Q4 will come closer to Mars than Earth by about a factor or two or so. The HiRISE camera is probably the best in Mars vicinity but it has an aperture of "only" 50 cm and lacks many instruments like spectrographs so Hubble and earth based telescopes will be able to gather much better data.
    Just a nitpick, but if you are looking in the visible range, that's certainly true. But for observations at other wavelengths, like (relevant in this case) infrared, it's better to use a space-based telescope because of the absorption. I realize that you meant in the visible range, but other people might not be aware of that so I added it.
    As above, so below

  6. #6
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    I think they are counting Earth-orbiting telescopes as "Earth-based."

    The previous interloper was long and skinny like a rocket, let's hope this one isn't shaped like a saucer!

  7. #7
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    ....or change course during its approach.

  8. #8
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    Rama(s)

    Quote Originally Posted by Ken G View Post
    I think they are counting Earth-orbiting telescopes as "Earth-based."

    The previous interloper was long and skinny like a rocket, let's hope this one isn't shaped like a saucer!
    Or is long and skinny, and is followed by a third similar object. In which case Arthur C. Clarke can be elevated to demi-god status.

  9. #9
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    Quote Originally Posted by Ken G View Post
    I think they are counting Earth-orbiting telescopes as "Earth-based."
    Right, I guess that makes sense. I was thinking of telescopes attached to the earth, but if itís orbiting I guess itís like being in a very tall, moving mountain.


    Sent from my iPhone using Tapatalk
    As above, so below

  10. #10
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    A couple of arxive papers:

    Interstellar comet 2I/Borisov

    https://arxiv.org/abs/1909.05851


    Sending a Spacecraft to Interstellar Comet C/2019 Q4 (Borisov)

    https://arxiv.org/abs/1909.06348

    It appears to have a tail which can source non-gravitational accelerations. This is one difference from Oumuamua that did not show an evident tail.

  11. #11
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    It wasn't that long ago that Mars got buzzed by a comet.

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