Updated qview (markdown)

![planareq]

![planareq2]

![planareq1]

An example of using the Measure Tool to measure the Planar Kilometer distance of a volcanic plume above Io is shown below: 

Match

[planareq]: http://chart.apis.google.com/chart?cht=tx&chl=\theta=\arccos{(\sin{(dec_1)}\sin{(dec_2)}+\cos{(dec_1)}\cos{(dec_2)}\cos{(RA_1-RA_2)})}

[planareq2]: http://chart.apis.google.com/chart?cht=tx&chl=d_{mesaured}=d_{slant}2\sin{\frac{\theta}{2}}

[planareq1]: http://chart.apis.google.com/chart?cht=tx&chl=d_{mesaured}=d_{slant}2\sin{\frac{\theta}{2}}