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  1. #821

    Japanese/SpaceX/UAE Moon Shot

    I ran across this interesting article this morning:
    https://apnews.com/article/science-b...7593eb1d1fdd9d

    It is about the recent SpaceX launch carrying a Japanese and a UAE rover that will be headed to the Moon, on a 'slow boat' course to minimize fuel; probably not what you would want to do with people on board.

    Of particular interest to me is that the UAE rover is named Rashid after the Dubai Royal Family.

    Sheikh Mohammed bin Rashid Al-Maktoum, Vice President and Prime Minister of the United Arab Emirates, and the owner of the power Godolphin stable and breeding operation.

    Larry
    DevilHorse

  2. #822
    Join Date
    Nov 2007
    Location
    Vermont
    anyone else enjoying the current meteor shower? https://www.cnn.com/2022/12/13/world...scn/index.html

    we've been watching TV the last few nights and every once in a while we've seen a meteor zip on in, some are colorful.

  3. #823
    Join Date
    Feb 2013
    Location
    Cambridge, MA
    Quote Originally Posted by budwom View Post
    anyone else enjoying the current meteor shower? https://www.cnn.com/2022/12/13/world...scn/index.html

    we've been watching TV the last few nights and every once in a while we've seen a meteor zip on in, some are colorful.
    I'll have to check it out.

    Who doesn't love a good meteor shower? I'll tell you who. The people of 1833.

    I am currently reading Neil deGrasse Tyson's most recent book and he briefly mentions the meteor shower of 1833. Apparently, the Leonid meteor shower of Nov 13, 1833 was so intense ("upward of 100,000 [meteors] per hour - as many as 30 per second") that some level of mass hysteria ensued as many people believed that the end of days was upon them.

    Tyson shares a fun (apocryphal?) story of Abe Lincoln's experience.

    At the time, future president Abraham Lincoln was 24 years old and living in Illinois as a boarder with a deacon of the local Presbyterian church. Upon witnessing this unforgettable cosmic display, the deacon swiftly aroused Lincoln, declaring, “Arise, Abraham, the day of judgment has come!” A conclusion drawn from another apocalyptic verse in the Book of Revelation: “And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind.”

    Honest Abe, a self-educated, lifelong learner, dutifully went outside to look up at the night sky. Invoking his knowledge of astronomy, he noticed that all the grand constellations were still there, intact—Ursa Major, Leo, Taurus, Orion. Whatever was falling, it wasn’t the stars, so he rationally concluded that a biblical prophecy of doom was not under way and promptly went back to bed.
    How it is possible that I have lived on this planet for more than 50 years and didn't learn about the meteor shower of 1833 until this week?

    Apparently there was also quite a show in Nov 1966, but that was a bit before my time.

  4. #824
    Join Date
    Feb 2007
    Location
    Washington, DC area
    Fun XKCD today. We get to drive our own space ship and explore!

    https://xkcd.com/2712/

    Some stuff you can find:

    https://www.explainxkcd.com/wiki/ind.../2712:_Gravity

    -jk

  5. #825
    Quote Originally Posted by -jk View Post
    Fun XKCD today. We get to drive our own space ship and explore!

    https://xkcd.com/2712/

    Some stuff you can find:

    https://www.explainxkcd.com/wiki/ind.../2712:_Gravity

    -jk
    That space is warped.

    Larry
    DevilHorse

  6. #826
    Quote Originally Posted by WillJ View Post
    Thanks for the information, DH...very interesting. I hadn't thought of the possibility of a collision between coplanar objects.
    I was motivated to ask the question because of academic economists' concern about a "kessler spiral," which I guess occurs when orbiting satellites crash, creating trash, which creates more crashes, which creates more trash, until we have a trash field that would imped the launching of new satellites. Even after your information, I'm puzzled why the crashes - which are, as you note, not completely elastic - don't result in stuff falling to earth. My understanding (perhaps incorrect) is that any orbit is a very careful balance of altitude and velocity, and that any change in velocity at fixed altitude will result in either a fall to earth (if velocity is lost) or a leap off into outer space (if velocity is gained). So I'm still a bit confused, tbh.
    Here is an interesting attempted remedy for removing space junk:
    https://twitter.com/i/status/1604846680817352704

    Larry
    DevilHorse

  7. #827
    Join Date
    Feb 2007
    Location
    Washington, DC area
    Quote Originally Posted by DevilHorse View Post
    Here is an interesting attempted remedy for removing space junk:
    https://twitter.com/i/status/1604846680817352704

    Larry
    DevilHorse
    Seems like a really expensive way to go, a lot of mass to launch.

    -jk

  8. #828
    Quote Originally Posted by -jk View Post
    Seems like a really expensive way to go, a lot of mass to launch.

    -jk
    First is not necessarily (going to be) Foremost (listen to the Fusion people). Points made about this First approach includes that it does not address the smaller pieces. I imagine that could be addressed (partly) by sweeping with a mesh of some sort; of course, a mesh would potentially slow down the craft if it was too close to the atmosphere (act like a parachute). But the willingness to attack the engineering necessary to clean swaths of space has to be encouraging.

    Larry
    DevilHorse

  9. #829
    Quote Originally Posted by -jk View Post
    Seems like a really expensive way to go, a lot of mass to launch.

    -jk
    The theory is it's a lot less expensive to handle now than it will be if we let it get out of control. The problem is when two decent size pices collide and then make dozens of smaller pieces. All of which can now collide with other pieces and make more pieces. Eventually you get enough pieces when it's too dangerous in near earth orbit. This is called Kesseler Syndrome.

    https://en.wikipedia.org/wiki/Kessler_syndrome

  10. #830
    Join Date
    Sep 2007
    Location
    Undisclosed
    A short, cool video of how the soil samples being taken on Mars are planned to return to Earth:

    https://twitter.com/nasapersevere/st...G3c2tmTWhUT0Qg

  11. #831

    The Physics of Santa Clause

    Since the tracking of Saint Nick falls under the umbrella of astronomical observation, I thought I'd pass along this physics breakdown of the awesome job that Santa does:
    https://twitter.com/martinmbauer/sta...12536188010497

    Merry Christmas to all that celebrate (and to those who don't).

    Larry
    DevilHorse

  12. #832

    New Comet - C/2022 E3 (ZTF)

    A new comet was discovered a little more than a month ago, and will pass within 26M miles of the earth. For perspective, at its closest, Venus is 26M miles away from the Earth.
    https://interestingengineering.com/s...s-visible-2023
    It may be visible to the naked eye, but definitely to binoculars and telescopes.
    Naked eye visibility predictions to be in a few weeks (mid-January) (if at all).

    It hasn't been seen since the last Ice Age, 50,000 years ago. Homo Sapiens have only walked the earth for 300,000.

    How to spot the comet:
    https://metro.co.uk/2022/12/30/how-t...year-18015068/

    It really needs a catchy name.

    Larry
    DevilHorse

  13. #833
    Join Date
    Feb 2007
    Location
    Greenville, SC
    I found a youtube documentary on what to expect when the comet passes. The timing is off by a bit, but what's a few decades out of 65 million years?

    Linky to Night of Comet.

  14. #834

    James Webb Telescope

    I'm in the middle of watching an excellent Congressional hearing (from 12/15 I think) on the James Webb Telescope results and processes:
    https://www.c-span.org/video/?524287...scope-findings
    The name of the program on CSPAN is "Hearing on Space Exploration & the James Webb Telescope."

    Depending on your level of science background/appreciation, there is more than enough 'under the hood' information about (some) recent findings, technical issues, and future work.

    The panelists include a NASA Director in charge of this project (very good insight into technical considerations and broad view of the project), a deep space/ black hole specialist (concerned with new findings of the earliest universe discoveries and theories), and an Astrobiologist (addresses exoplanet findings and goals).

    Worthwhile if you have an hour and a half to spend.

    From a political perspective, it is good to see people from both sides of the aisle taking this all seriously.

    Larry
    DevilHorse

  15. #835
    Join Date
    Feb 2008
    Location
    New Bern, NC unless it's a home football game then I'm grilling on Devil's Alley
    This is great. A true scale model of the solar system. It had to be constructed on a dry lake bed, Earth is a marble.

    Q "Why do you like Duke, you didn't even go there." A "Because my art school didn't have a basketball team."

  16. #836
    Join Date
    Feb 2007
    Location
    Greenville, SC
    Quote Originally Posted by CameronBornAndBred View Post
    This is great. A true scale model of the solar system. It had to be constructed on a dry lake bed, Earth is a marble.

    As the Hitchhiker’s Guide explains it.

    “Space,” it says, “is big. Really big. You just won’t believe how vastly hugely mindboggingly big it is. I mean you may think it’s a long way down the road to the chemist, but that’s just peanuts to space. Listen …” and so on.

  17. #837

    Curiosity and the Green Comet

    Interesting find by the Curiosity rover:
    https://twitter.com/latestinspace/st...47149215907842

    Anybody hear about the Green Comet that will soon pass by earth?
    https://www.indystar.com/story/news/...3/69791991007/

    Larry
    DevilHorse

  18. #838
    Join Date
    Feb 2008
    Location
    New Bern, NC unless it's a home football game then I'm grilling on Devil's Alley
    Quote Originally Posted by DevilHorse View Post
    Interesting find by the Curiosity rover:
    https://twitter.com/latestinspace/st...47149215907842

    Anybody hear about the Green Comet that will soon pass by earth?
    https://www.indystar.com/story/news/...3/69791991007/

    Larry
    DevilHorse
    I'll be pulling out my 8" reflector for the comet, hopefully this weekend. There are a couple places within a short drive that I can set up for a good view. Today it's at its perihelion.
    Q "Why do you like Duke, you didn't even go there." A "Because my art school didn't have a basketball team."

  19. #839

    Got Orrery

    In elementary school, we had an orrery that had only the nine planets.

    This orrery is fantastic:
    https://twitter.com/i/status/1614202053118644224

    Note that it accurately has the plane of the moons of Uranus perpendicular to the ecliptic.
    Great stuff.

    Larry
    DevilHorse

  20. #840
    Quote Originally Posted by DevilHorse View Post
    In elementary school, we had an orrery that had only the nine planets.

    This orrery is fantastic:
    https://twitter.com/i/status/1614202053118644224

    Note that it accurately has the plane of the moons of Uranus perpendicular to the ecliptic.
    Great stuff.

    Larry
    DevilHorse
    Awesome! I would LOVE to own that but I’m reluctant to inquire about the cost - the answer would likely just depress me.

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