• Close Approach Comets

    From Roger Nelson@1:3828/7 to All on Fri Apr 21 22:34:18 2017
    Close Approach Comets

    Comets are some of the most interesting objects in the solar system. Water that
    filled the ancient oceans of Earth might have been delivered by comets. And there is growing evidence that many comets (as well as some primitive asteroids) contain molecules key to life. NASA has sent space probes to travel hundreds of millions of miles to study these icy interlopers from the outer solar system.

    https://www.youtube.com/watch?v=j-Vz38ECJh0

    Comets are balls of frozen gases, rock and dust that orbit the sun. Jets of gas
    and dust from comets form long tails that can be seen from Earth when they fly close enough to our planet.

    In 2017 and 2018, three comets will pass near the Earth.

    Their names are 41P/Tuttle-Giacobini-Kresak, 45P/Honda-Mrkos-Pajdusakova, and 46P/Wirtanen. Astronomers call them "41P", "45P", and "46P", for short.

    At closest approach on April 1, 41P was only 56 times farther from Earth than the Moon. 45P was even closer at 31 lunar distances when it flew by on February
    11. And 46P approaches 30 lunar distances, on December 16, 2018.

    Kelly Fast, Program Manager in the Near-Earth Object Observations Program at NASA Headquarters says, "This provides a good opportunity to do science without
    having to launch a spacecraft."

    Telescopes around the world have been trained on the comets as they pass by, studying their structure and chemical compositions.

    For the general public, comet 45P was an easy target for small telescopes when it passed closest to Earth in February, and 41P will be an easy telescope target through May of 2017. But 46P will be the biggest attraction. In December
    2018, it could be visible to the naked eye from dark sky sites.

    Astronomer Tony Farnham of the University of Maryland says, "46P has a small nucleus, but is known to be a `hyperactive' comet. It is probably ejecting ice crystals from its surface, producing higher than normal activity."

    This hyperactivity may contribute to the naked-eye brightness of 46P. It also makes the comet somewhat unpredictable with unexpected surges in activity-and visibility-possible as it passes by.

    These comets have been so close that amateur astronomers can help study them, too. Farnham is assisting Nalin Samarasinha at the Planetary Science Institute in Tuscon, Arizona with the organization of the "4*P Coma Morphology Campaign" to coordinate the efforts of amateurs worldwide.

    "Amateur astronomers can help us monitor these comets without interruption," explains Farnham. "With observers distributed around the world, we can get much
    better coverage, with fewer and shorter breaks."

    "We can then combine amateur observations with observations from professional telescopes to study the structures in the comet's atmosphere-or `coma.' If we use the amateur data in our studies, then they get to be an author on any papers that result."

    "A few years back, we used this same type of network for our studies of comet ISON, and they proved very successful, with data from 23 different groups around the world."

    For more about objects in and around Earth's neighborhood, stay tuned to science.nasa.gov.


    Regards,

    Roger

    --- DB 3.99 + W10 (1703)
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)
  • From JIMMY ANDERSON@1:116/18 to ROGER NELSON on Sat Apr 22 22:35:00 2017
    Roger Nelson wrote to All <=-

    Close Approach Comets

    <snip>

    VERY cool! Be sure to remind us of the one that might
    be visible to the naked eye!

    I heard on a podcast this morning about the solar
    eclipse this year and being visible "Oregon to
    South Carolina" - so I looked it up and the path
    of totality will pass over Nashville! That's only
    a few hours from me!

    It will also pass over Paducah, KY. It's the Monday
    after Gencon, so I will be coming home from Indianapolis
    Sunday night or Monday anyway - just got to time it
    right so I'm in Paducah during zero hour!

    woo-hoo ! Exciting! I never thought I'd get a chance
    to see a total solar eclipse! There was a partial
    for us when I was in 6th grade and then the day our
    oldest son was born in 1991 there was a partial, but
    of course I didn't even try to see it. :-)



    ... I had a cat once... tasted like chicken.
    --- MultiMail/Darwin v0.49
    * Origin: Neptune's Lair - Olive Branch MS - winserver.org (1:116/18)
  • From Roger Nelson@1:3828/7 to JIMMY ANDERSON on Sun Apr 23 06:43:20 2017
    On Sat Apr-22-2017 22:35, JIMMY ANDERSON (1:116/18) wrote to ROGER NELSON:

    Roger Nelson wrote to All <=-

    Close Approach Comets

    <snip>

    VERY cool! Be sure to remind us of the one that might
    be visible to the naked eye!

    Thanks. I post them as soon as I get them, so stay tuned.

    I heard on a podcast this morning about the solar
    eclipse this year and being visible "Oregon to
    South Carolina" - so I looked it up and the path
    of totality will pass over Nashville! That's only
    a few hours from me!

    I track those, too.

    It will also pass over Paducah, KY. It's the Monday
    after Gencon, so I will be coming home from Indianapolis
    Sunday night or Monday anyway - just got to time it
    right so I'm in Paducah during zero hour!

    woo-hoo ! Exciting! I never thought I'd get a chance
    to see a total solar eclipse! There was a partial
    for us when I was in 6th grade and then the day our
    oldest son was born in 1991 there was a partial, but
    of course I didn't even try to see it. :-)

    They don't last long and one thing you should be mindful of -- NEVER look at them no matter how safe you think it is.


    Regards,

    Roger
    --- timEd/386 1.10.y2k+ W10 (1703)
    * Origin: NCS BBS - Houma, LoUiSiAna - (1:3828/7)