NavList:

Ken Harris, yesterday, you asked:
"How sensitive is this to "haze" ?"

Sensitive, but it's not a show-stopper. This morning the sky was clear, but it was not deep blue. The color changed from bluish white down low to white-ish blue 45° high and did not really look like a clear blue sky until quite high up. Even so, Venus was an easy mark (abour 32° high) as soon as I was looking at the right spot. 

You wrote:
"I was thinking about this back in January when I was trying to see Mercury and wondered if it possible to predict when Mercury will be brighter than the haze."

It's a good question worthy of more observational evidence and some physical analysis, too. Russ Sampson at Eastern Connecticut State University is interested in this issue, and we have discussed circumstances for observing Jupiter in daylight. So far Jupiter seems to be impossible without optical aid --except when the Sun is within a degree or so of the horizon. But does that count? Technically, it's still daylight. Sometimes even civil twilight is counted as "daylight" and I find that a dozen or more stars can be seen before the end of civil twilight, even stars as faint as magnitude 2.5 (Mintaka is a good test case this time of year). As with Venus, you have to know exactly where to look. For full daylight, near sea level, when the Sun is higher than, let's say, 10°, it seems that the limit is between magnitude -3.5 and -4.0. And that implies our full daylight "naked eye" objects are limited to the Sun and Moon, Venus, rare supernovae, and an occasional comet. 

With a small telescope, I have seen Jupiter in daylight a number of times. It's easiest when it's close to the Moon or Venus. There's an opportunity to try this on April 30 when Jupiter and Venus will be separated by less than half a degree. Conjunctions of Jupiter and Venus are always photogenic. Expect a social media barrage. :)

Frank Reed