Presentation is loading. Please wait.

Presentation is loading. Please wait.

Dr Paul A Daniels, Guildford Astronomical Society.

Similar presentations


Presentation on theme: "Dr Paul A Daniels, Guildford Astronomical Society."— Presentation transcript:

1 Dr Paul A Daniels, Guildford Astronomical Society

2  Solar System to Size Scale M any V olcanoes E rupt M ulberry J am S andwiches U nder N ormal P ressure M any V olcanoes E rupt M ulberry J am S andwiches U nder N ormal P ressure Mary’s ‘Virgin’ Explanation Made Joseph Suspect Upstairs Neighbour Mary’s ‘Virgin’ Explanation Made Joseph Suspect Upstairs Neighbour X 2 2

3  Background  Naked-Eye Venus  Historical Observations  Venus’ Orbit  The Planet  Simple Geometric Brightness  Lambertian Brightness  Comparisons and Conclusions  Background  Naked-Eye Venus  Historical Observations  Venus’ Orbit  The Planet  Simple Geometric Brightness  Lambertian Brightness  Comparisons and Conclusions 3 3

4 4 4 31 st May 2011 Jupiter  Mars  Venus  Mercury  Moon  Superior Conjunction Inferior Conjunction Greatest Eastern Elongation Greatest Western Elongation

5 5 5  Greeks – up to 6 th century BCE  Phosphorus (‘Light Bringer’, Morning Star)  Hesperus (Evening Star)  Half-brothers of Eos the Greek goddess of the dawn  Romans – up to 6 th century BCE  Lucifer (‘Light Bringer’, Morning Star)  Vesper (Evening Star)  Half-brothers of Aurora the Roman goddess of the dawn  Greeks – up to 6 th century BCE  Phosphorus (‘Light Bringer’, Morning Star)  Hesperus (Evening Star)  Half-brothers of Eos the Greek goddess of the dawn  Romans – up to 6 th century BCE  Lucifer (‘Light Bringer’, Morning Star)  Vesper (Evening Star)  Half-brothers of Aurora the Roman goddess of the dawn

6 6 6  Babylonians – 15 th century BCE  From the Venus tablet of Ammisaduqa we know they knew they were one object  Pythagoras – late 6 th century BCE  Realised that they were the same object  Wrongly thought that Venus revolved around the Earth  Babylonians – 15 th century BCE  From the Venus tablet of Ammisaduqa we know they knew they were one object  Pythagoras – late 6 th century BCE  Realised that they were the same object  Wrongly thought that Venus revolved around the Earth

7 7 7  Nicolaus Copernicus – 16 th century CE  Supported Heliocentric view of the Solar system – Venus orbits the Sun!  Galileo Galilei – 17 th century CE  Observed phases on Venus – contradicts Ptolemaic system  Johann Schröter – 1790 CE  Observed Venus’s atmosphere  Nicolaus Copernicus – 16 th century CE  Supported Heliocentric view of the Solar system – Venus orbits the Sun!  Galileo Galilei – 17 th century CE  Observed phases on Venus – contradicts Ptolemaic system  Johann Schröter – 1790 CE  Observed Venus’s atmosphere

8 8 8  Orbit Parameters  a= 0.72333 AU = 108,208,000 km  e= 0.00678  i= 3.395°  P sid = 224.701 days (Sidereal)  P syn = 583.92 days (Synodic)  Orbit Parameters  a= 0.72333 AU = 108,208,000 km  e= 0.00678  i= 3.395°  P sid = 224.701 days (Sidereal)  P syn = 583.92 days (Synodic) Perfect Circle Mercury’s Orbit e = 0.20563

9 9 9 Go! Reset

10 10  The Planet  R= 6,051 km = 3,760 mi = 95% R  R= 6,051 km = 3,760 mi = 95% R  M= 4.8676 x 10 24 kg = 81.5% M  M= 4.8676 x 10 24 kg = 81.5% M  The Atmosphere  Surface temperature = 737 K = 462 °C  Surface pressure = 92 bar = 9.2 MPa = 90.8 x Earth  ≈ 96.5% Carbon Dioxide and ≈ 3.5% Nitrogen  0.015% Sulphur Dioxide0.0017% Carbon Monoxide  0.007% Argon0.0012% Helium  0.002% Water Vapour0.0007% Neon  Trace Carbonyl Sulphide, Hydrogen Chloride & Hydrogen Fluoride

11 11

12 12 Frames 132 & 228 : Greatest Elongation East & West Frames 156 & 204 : Greatest Brilliancy East & West

13 13

14 14

15 15 Frames 132 & 228 : Greatest Elongation East & West Frames 148 & 212 : Greatest Brilliancy East & West

16 16 The Geometric Phase Angle and timings are the ones almost universally quoted in the literature! No mention anywhere of angles or timings that correspond to the Lambertian analysis.

17 17  What other possibilities?  I’m sane everyone else is mad!  Difficult to accurately measure Venus’ brightness?  Geometric quoted so often it’s taken as the only version?  Answers on a postcard please…  What’s Wrong?  My Intuition/Assumptions?  My Physics/Maths!  What’s Wrong?  My Intuition/Assumptions?  My Physics/Maths!

18

19 Superior Conjunction Inferior Conjunction Greatest Eastern Elongation Greatest Western Elongation

20


Download ppt "Dr Paul A Daniels, Guildford Astronomical Society."

Similar presentations


Ads by Google