• How is it that we have these powerful telescopes on Earth and outer space but we can not locate nor photograph the massive “Planet 9” ?

    Best answer: The amount of light we get from an object diminishes with the squre of the distance. Twice as far = 4 times dimmer; three times as far = 9 times dimmer. The amount of light reflected by a planet depends on its distance from the Sun. Twice as far = it gets 1/4 of the light intensity; three times as far = it... show more
    Best answer: The amount of light we get from an object diminishes with the squre of the distance. Twice as far = 4 times dimmer; three times as far = 9 times dimmer.
    The amount of light reflected by a planet depends on its distance from the Sun. Twice as far = it gets 1/4 of the light intensity; three times as far = it gets.

    Compared to "Planet 9", Pluto is very close to us (and closer to the Sun than Planet 9). In addition, Pluto is not really a planet (in that sense) but closer to a comet nucleus -- albeit a giant one. It reflects a lot more sunlight than a "normal" planet surface would. That is why it was thought, for a long time, to be a lot bigger than it really is.

    If Planet 9 is a real planet (darker in color than Pluto) AND if it is in orbit at an average distance of 700 AU (astronomical units -- 1 AU = Earth's orbital distance) then it is 17.5 times further away from the Sun as Pluto.
    (17.5)^2 = 306.25

    It is illuminated by sunlight that is 300 times dimmer than what Pluto gets.
    The light we would get from it will be 300 times dimmer than what we would get if Planet 9 was near Pluto.

    And its relative motion (its orbital speed) would be a lot slower than Pluto's orbital speed (which is a pedestrian 4.67 km/s). Planet 9's orbital speed would be barely above 1 km/s (compare to Earth's orbital speed of 30 km/s).
    At that distance, it would barely move by 2' per day (it would take two weeks for this planet to move by the equivalent of the apparent diameter of our Moon).

    Summary: this Planet 9 is expected to be A LOT fainter than Pluto, and it would move extremely slowly over short periods. Plus, we don't know in which direction it would appear, as seen from Earth (it is not even expected to be near the ecliptic like "normal" planets are).
    13 answers · 2 weeks ago
  • Welp math hw?

    Pluto has been hard to measure from Earth because of its atmosphere. In 2007 Young, Young, and Buie measured Pluto as having a diameter of 2322 km. The New Horizons probe traveled to Pluto and measured it up close and we now know the actual size is 2372 km. What was the relative error of the 2007 measurement?
    Pluto has been hard to measure from Earth because of its atmosphere. In 2007 Young, Young, and Buie measured Pluto as having a diameter of 2322 km. The New Horizons probe traveled to Pluto and measured it up close and we now know the actual size is 2372 km. What was the relative error of the 2007 measurement?
    6 answers · 2 weeks ago
  • What lies outside the universe?

    Best answer: Our beloved God and king, Jehovah.
    Best answer: Our beloved God and king, Jehovah.
    4 answers · 2 weeks ago
  • If i drove "straight-up" in my car at 70 mph, how long would it take me to reach outer-space?

    Best answer: If you wanted to get *completely* out of the atmosphere, you'd need to travel about 300 miles straight up, so since Time is equal to Distance divided by Rate:
    T = 300/70 = 4.2857 hours
    Best answer: If you wanted to get *completely* out of the atmosphere, you'd need to travel about 300 miles straight up, so since Time is equal to Distance divided by Rate:
    T = 300/70 = 4.2857 hours
    4 answers · 2 weeks ago
  • What should I do with my physics degree? (astronomy emphasis)?

    I am currently gaining a bachelors in physics with an astronomy emphasis, but I really don t know what to do after I graduate. I ve always wanted to work for NASA and be an astrophysicist, but I feel like that sounds vague. What specific jobs are there? I know I can t do any of the big stuff with just a bachelors,... show more
    I am currently gaining a bachelors in physics with an astronomy emphasis, but I really don t know what to do after I graduate. I ve always wanted to work for NASA and be an astrophysicist, but I feel like that sounds vague. What specific jobs are there? I know I can t do any of the big stuff with just a bachelors, but where can I start?
    14 answers · 3 weeks ago
  • What is the coldest place in the Universe?

    14 answers · 3 weeks ago
  • Does earth ever shift direction of it rotation.?

    Best answer: No it n has too much momentum to reverseever changes rotation, it slows over billions of years but
    Best answer: No it n has too much momentum to reverseever changes rotation, it slows over billions of years but
    18 answers · 3 weeks ago
  • Do you think, after the launch of the JWT the universe will suddenly be bigger than 90 billion light years than it's currently believed?

    I think the James Web Telescope will peer deeper into space than the HST was ever able too. We will see light coming from objects that are farther away than 45 billion light years (the edge of visible space as we speak now). It will then also be calculated older than currently thought. Hopefully this question will... show more
    I think the James Web Telescope will peer deeper into space than the HST was ever able too. We will see light coming from objects that are farther away than 45 billion light years (the edge of visible space as we speak now). It will then also be calculated older than currently thought. Hopefully this question will still be here after 10 years or so. Since we now 'think' the universe is 13.77 billion years old and roughly 90 billion light years in (visible) size. Same applies for our Milky Way, we thought it was 100,000 lightyears big, now it's suddenly nearly 200,000 lightyears, matching up with Andromeda.
    7 answers · 2 weeks ago
  • Could any star that was in the Early Universe, still be alive and active?

    Best answer: Yes, indeed. HE 1523-0901, for instance, is estimated to be 13.2 billion years old.

    http://mcdonaldobservatory.org/news/rele...

    SMSS J031300.362670839.3 is possibly even older:

    https://www.space.com/24625-oldest-star-...
    Best answer: Yes, indeed. HE 1523-0901, for instance, is estimated to be 13.2 billion years old.

    http://mcdonaldobservatory.org/news/rele...

    SMSS J031300.362670839.3 is possibly even older:

    https://www.space.com/24625-oldest-star-...
    9 answers · 3 weeks ago
  • Why do all planets and moons spin?

    9 answers · 3 weeks ago
  • Why are humans so fascinated by aliens?

    13 answers · 3 weeks ago
  • Who will maintain the machines/robots when humanity has to be evacuated from planet Earth?

    Best answer: By then they will be advanced enough to take care of themselves.
    Best answer: By then they will be advanced enough to take care of themselves.
    14 answers · 3 weeks ago
  • Would you like to live in the year 3000?

    Best answer: What would a person from year 1000 think of what we have now? It would be magic to him. Voices coming out of a box, tiny people on a screen, flying machines, horseless carriages, light without fire. We would think year 3000 people can do magic. I can't begin to imagine what technology they will have. Can you?
    Best answer: What would a person from year 1000 think of what we have now? It would be magic to him. Voices coming out of a box, tiny people on a screen, flying machines, horseless carriages, light without fire. We would think year 3000 people can do magic. I can't begin to imagine what technology they will have. Can you?
    8 answers · 3 weeks ago
  • What is beyond the universe?

    Another universe, more of the same universe or what?
    Another universe, more of the same universe or what?
    98 answers · 4 weeks ago