English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Over the course of 3.1 years we determined the position of Mars on 75 datesusing a handheld cross staff and two to five bright reference stars of knownright ascension and declination on each occasion. On average the observedpositions of Mars are within +/- 11 arc minutes of the true ecliptic latitudesand ecliptic longitudes. After deriving the two dates of opposition to the Sun,we were able to carry out a two stage analytical experiment on Mars' orbit.From the 2015/2016 data we obtain a value of the eccentricity of 0.093 +/-0.012. The 2015/2016 data can be fit reasonably well by adopting a circularorbit for the Earth, but the 2017/2018 data must be fit with an ellipse forMars and an ellipse for the Earth. Applying the two ellipse model to the2015/2016 data, we obtain an RMS error of the ecliptic longitudes of only +/-7.5 arc minutes. While Kepler was able to derive the shape of Mars' orbit whilerelying on data of Tycho Brahe accurate to +/- 2 arc minutes, today we mayassume an ellptical orbit, and we can show that much less accurate data areconsistent with an ellipse having an eccentricity equal to the modern acceptedvalue of 0.0934, within the errors.

Demonstrating the Elliptical Orbit of Mars using Naked Eye Data