Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A Series of Exoplanets in Our Solar System

  1. Mar 4, 2017 #1
    In this alternate universe, Earth is the same as back home--8,000 miles wide, 25,000 around, six sextillion tons, orbiting a G-type main-sequence star from a distance of 93 million miles. But here, the similarities end.

    MOON
    DIAMETER--3,273 miles
    MASS--0.025x that of Earth
    DISTANCE FROM EARTH--475,000 miles

    MERCURY (based on 55 Cancri e)
    DIAMETER--2x that of Earth
    MASS--8x that of Earth
    DISTANCE FROM THE SUN--1.4 million miles

    VENUS (based on Kepler-69c)
    DIAMETER--1.75x that of Earth
    MASS--5.5x that of Earth
    DISTANCE FROM THE SUN--67.24 million miles

    MARS (based on Gliese 1214 b)
    DIAMETER--2.7x that of Earth
    MASS--7x that of Earth
    DISTANCE FROM THE SUN--141.6 million miles

    Jupiter, Saturn and Uranus are identical in diameter, mass and distance from the sun to back home. Neptune, however, does not exist.

    There are two important factors to consider that most scientists believe are connected to the orbital mechanics of our solar system.

    The first and more obvious is the asteroid belt, leftovers of rock, ice and metal that survived the mighty pull of the gas giants.

    There is a second, more complicated factor connected to the solar system — the Milankovitch cycles, named after Serbian geophysicist/astronomer Milutin Milankovitch. He proposed that the ice ages Earth had been experiencing for the past two-and-a-half million years were made possible by three basic factors:

    • Eccentricity (Orbital shape) — In an average ice age, the shape of the Earth’s orbit varied from 0.000055 to 0.0679 with the mean being 0.0019 over a cycle of 100,000 years.
    • Obliquity (Axial tilt) — In an average ice age, the earth’s axis varies from 22.1 degrees to 24.5 degrees over a period of 41,000 years.
    • Precession (Axis of rotation in relation to fixed stars) — Today’s North Star is Polaris, but won’t be the case forever — its supposed duration is 26,000 years.

    Using the details provided above, what will Earth's nightscape look like? And how will these changes affect Earth's Milankovitch cycles?
     
  2. jcsd
  3. Mar 6, 2017 #2
    I have news for you: they've (in real life) found a Super-Earth beyond the Kuiper Belt.
     
  4. Mar 7, 2017 #3

    That doesn't answer the question.
     
  5. Mar 9, 2017 #4
    We don't even understand the ice age cycles of our Earth. The most important factor seems to be the 40 ky cycle of the axis tilt. A low tilt causes the polar caps to grow and high tilts let them melt. The 40 ky ice age cycles of the early Pleistocene can be explained with this single factor only. In the late Pleistocene there must have been at least one addional factor because several of the melting opportunities during the maximum tilt have been missed, resulting in 80 ky or 120 ky cycles (with an average of 100).

    To estimate the length of an ice age cycle on your Earth you would need to calculate the duration of the wobbling of the Earth axis with the data od the modified Moon. Everything else (how strong the ice ages are, how many wobbling cycles they last or if there are ice ages at all) is your artistic licence.
     
  6. Mar 9, 2017 #5

    Meaning?
     
  7. Mar 9, 2017 #6
    Care to provide a link concerning this discovery of a new large planet in the solar system?
     
  8. Mar 9, 2017 #7
    I have no idea. I just know the result for Earth as we know it but I didn't found a corresponding calculation.
     
  9. Mar 9, 2017 #8
    Look it up on YouTube under 7 top scientific discoveries.
     
  10. Mar 9, 2017 #9
    I'm curious if YouTube counts as ligitimate reference.
     
  11. Mar 9, 2017 #10
    YouTube is not a reputable source of scientific discoveries.
    You can find accounts of UFO abductions, ghosts, and miracle cures for cancer on YouTube.
     
  12. Mar 9, 2017 #11
    No they haven't. They just have a good suspicion of where one might be. Also, due to "Clearing the neighborhood", we might never know if we can call it a planet or not.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: A Series of Exoplanets in Our Solar System
  1. Our Solar System name? (Replies: 3)

Loading...