|1. Turn off the daylight and horizon displays. Use the
“Planet” Palette to center on Uranus and lock on
Uranus. Use the “Zoom” button to set the field of
view to about 50°. Use the Selection Tool to point at
Uranus and then right click on the mouse buttons. Select
Info Window and record when Uranus rises and
when it transits (crosses the celestial meridian). Click
on File and then Print to print a chart of Uranus and
the stars around it. If possible, use the chart to look for
Uranus while it is in the sky tonight. If you can’t see it
with the unaided eye, try binoculars.
2. Turn off the daylight and horizon displays. Use the
“Planet” Palette to center on Neptune and lock on
Neptune. Use the “Zoom” button to zoom in until
Neptune is about 2 inches across on your monitor.
Point at Neptune using the Selection Tool to click on
and record the distance of Neptune. Using the Angular
Separation Tool, find the angular diameter of Neptune.
Use the Small Angle Equation (Equation 3.1) to find
the diameter of Neptune. (You will have to use Appendix
2 to convert AU to km.) Compare your answer
with the diameter of Neptune given in Appendix 6.