1
$\begingroup$

In the game i'm working on the Earth was hit by a Coronal Mass Ejection during a solar eclipse. I'm looking for dates between 2100 and 2300 where a base on Ceres would be protected by being in the shadow of the Earth.

The story requires the base on the far side of the moon and most space infrastructure being destroyed at the time.

$\endgroup$
10
  • 2
    $\begingroup$ This question is not about Worldbuilding, and thus would not be a good fit for this Stack Exchange. I recommend moving your question to the Astronomy stack exchange. $\endgroup$
    – stix
    Nov 9, 2022 at 20:55
  • 1
    $\begingroup$ And that would be done how? $\endgroup$
    – Rasip
    Nov 9, 2022 at 21:15
  • 2
    $\begingroup$ Most likely there is no such perfect alignment, eclipse or no eclipse; the orbit of Ceres has a different inclination than the orbit of the Earth, so that the little planet would need a very large dose of luck to find itself ever perfectly aligned with the Earth and the Sun. (And Ceres is really far away; Earth is much too small to offer significant protection from a coronal mass ejection.) (Especially given that the Moon itself could not protect Earth, and the Moon is so very much closer...) $\endgroup$
    – AlexP
    Nov 9, 2022 at 21:17
  • 1
    $\begingroup$ It's a videogame, of course the rule of cool has to be kept in mind and balanced against reality. $\endgroup$
    – Rasip
    Nov 9, 2022 at 23:20
  • 2
    $\begingroup$ (a) Why did someone downvote this question? +1 to counter that vote. (b) While John's answer is correct and the comments by Gault and AlexP are both valuable - who cares?! You're completely right about the "Rule of Cool." It's not impossible for Earth to shield Ceres, just so unlikely that it's not worth trying to calculate everything. Forget everything we've said and use the idea anyway. I like it. $\endgroup$
    – JBH
    Nov 9, 2022 at 23:37

1 Answer 1

4
$\begingroup$

While you have the hard-science tag on this question, the answer is "Earth cannot shield Ceres from a CME." Earth is not nearly large enough to do the job: if it ever transits the Sun as seen from Ceres, it will be a small black dot, smaller than we see Venus as when it transits the sun as seen from Earth.

A CME also takes a long time to reach as far as Ceres, somewhere around 14 days, and due to the inverse square law, will be much less damaging at that distance.

$\endgroup$
2
  • $\begingroup$ Not the answer i was hoping for, but i can work with this. Thank you. $\endgroup$
    – Rasip
    Nov 9, 2022 at 23:15
  • 1
    $\begingroup$ Dead on correct. People sometimes think all the solar rays are leaving the sun and traveling in parallel. They're not. The only way Earth could shield Ceres is for the Earth to be almost as large as than the sun. An easy way to see this is to roll paper out on your table. Draw to scale the diameter of the sun at one end, the diameter of Ceres at the other, and then note where Earth is between them. Draw lines from Ceres poles to the Sun's poles. The distance between the lines at Earth's orbit is how large Earth would have to be to shield Ceres. $\endgroup$
    – JBH
    Nov 9, 2022 at 23:32

Not the answer you're looking for? Browse other questions tagged .