As far back as our collective memory extends, we’ve been mesmerised by the dance of the planets across our skies. Even now, despite all our knowledge and technology, their basic movements can still surprise and captivate us.
The waltz between Earth and Venus around the Sun has been doing just that, for centuries – and it certainly does make a stunning pattern.
This viral gif, posted by Matthew Henderson on Tumblr, plots the midpoint between the two planets through time – Venus in orange and Earth in blue – as they follow their usual paths around the Sun.
As Henderson explains in the caption, “eight Earth years are roughly equal to 13 Venus years, meaning the two planets approximately trace out this pattern with 5-fold symmetry as they orbit the Sun.”
The beautiful animation is based on data from University of Wisconsin geoscientist Steven Dutch, who created an interactive graphic in 2012, demonstrating how Venus’s closest orbital points to Earth, over eight years, map out the points of a “remarkable, but not perfect” pentagram in the sky.
“The orbits are approximated as circles, so this animation cannot be used for accurate predictions,” Dutch stated.
All planets have elliptical orbits, making these diagrams simplified representations of the real deal. But they aren’t radically far off, especially in Venus’s case. Venus has the most circular orbit of any of the planets in our Solar System.
In a measure of eccentricity – how much an orbit deviates from a circle – Venus scores 0.007, whereas Mercury, with the most elliptical planetary orbit in our Solar System, has an eccentricity of 0.21. This measurement is the ratio between a planet’s farthest and nearest orbital point from the Sun, and gives a sense of how elongated the ellipse is.
Earth’s eccentricity is 0.0167, and the Sun isn’t central to this ellipse – it’s closer to one end.
