viewed from Mars, which planets will show phases?
a) Saturn, Uranus and Neptune.
b) Only Venus.
c) Mercury and Venus.
d) Mercury, Venus, and Earth.
Draw a picture to show the Sun and the orbits of Venus, Earth, and Mars. Draw a filled circle to show the spot in Venus' orbit where Venus will show a new phase as seen from Earth, and an open circle to show where Venus will show a full phase. Draw the same for Mars as seen from Earth.