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Couldn't resist. Added a fifth Easter egg in the sky, for Planet Earth. Easter on April 1
doesn't come often...
In fact, Earth is visible from Mars, a bright apparition in the night. It would be somewhat
like a moon: an illuminated planet rather than an actual star. Both Mars and Earth orbit
the Sun, but Mars is 1.5 x further away, and orbits more slowly. The length of the day
is roughly the same - and the Sun rises in the East and sets in the West there, as well -
but a year is twice as long. Its mass is .38 that of Earth!!
Some pictures below. The sun is there but smaller, and the sky is tinted pink while
the light around the sun appears blueish. The first is the night sky, with Earth as the
one bright dot. The second is a sunset. The third, relative orbits.
sources: NASA
Wikipedia
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Here's the difficulty: if we take Newton's law of universal gravitation as
foundationnal: masses will attract as a function of the square of the distance
between them ie that attraction will decrease exponentially with distance,
then we are dealing with a system. At each and every measure, all actors have
moved and the equation governing their behavior will have changed. That's the
problem with finding when Earth and Mars will be at their closest, given the
presence of other planets...etc.
We currently consider that both Earth and Mars have elliptical orbits. They will be at their
closest when Mars is at it's closest to Sun, and Earth at it's farthest (and thus closest to Mars);
Mars and the Sun being in opposition with respect to Earth. Doesn't happen very often. But there
are moments of greater closeness.
https://www.universetoday.com/14824/distance-from-earth-to-mars/
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In point of fact, planets are not visible during the day because
Mars is very dusty. And the photos we do have show a smaller Earth than that dot.
But in 2050, Earth and Mars will be at their closest again...💁
http://planetfacts.org/size-of-planets-in-order/
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