Astromutt, questions about comets.

Does a comet lose more mass the closer it gets to the sun, or is it always losing mass because heat does not transfer through space, but radiation does, so the comet is always being pelted by radiation - but we don't see the tail until it's close enough to be illuminated unto us to view?

The radiation that hits the earth more perpendicular causes more heat, so I would also assume the same thing happens to a comet in space where the direct radiation from the radiation source (star) is causing more loss of mass around the comet's "equator" and at that only a small percentage, especially since the material coming off shields the comet itself for a brief moment.

Also, is the material coming off the comet slowing down or not? Why is it giving an apparent view of slowing down while the comet continues it's relative speed beyond it?

And, aren't comets going faster and faster since they are sling-shot around the star? In other words their speed increases over their life-span? And if so, that would mean they "decay" slower over time, correct?

Thanks for sharing your knowledge and consideration.