Earliest evening start times for public observing sessions

Please note:

• We change the earliest start times every 15 days based on when true darkness begins
• We can start half an hour earlier if the target is the moon or bright planets
• Times for March 11 - November 4 assume Daylight Savings is in effect.

That said, here are the earliest evening start times for 2007.

The above are the earliest start times, an important consideration for youngsters. For various reasons we may agree on a later start time for any given session.

When is the best date and time for a public observing session?

There are a lot of things we can observe any night that it is clear, but obviously the weather is the biggest factor restricting observing and this is unpredictable, so we make a final decision a couple of hours before an observing session is to begin. We can’t see through clouds, but some nights we can observe between them.

That said, factors restricting when and what you can see are:

• Time when true darkness begins.
• Whether or not a bright moon is in the sky making other objects dim. (Of course sometimes we want to observe the moon, but other times it’s a big, bright nuisance!)
• What’s in the sky at an altitude that makes for good observing and isn’t blocked by trees or buildings. The stars change constantly with the season, and the planets change constantly in a less predictable fashion. Meteor showers come and go, and a comet may drop in at any moment, but we seldom know when or where.

All these factors make a good observing session an experience to be valued when the opportunity is available. This is why we ask you to commit to a time and date in advance, and honor that commitment if the weather permits.

The public observing sessions are usually limited to the early evening hours and begin after sunset when it is dark enough to see what you plan to see. For looking at the moon and bright planets (Venus, Mars, Jupiter and Saturn) observing can start about 30 minutes nefore the times given. For observing stars, star clusters, nebulae, and galaxies we have to wait to begin until about an hour and a half after sunset for really dark skies - and these are the times used here.

Look at the preceding times and you will see that for youngsters, the window of observing opportunity can be very restricted.

For children in the 8-12 age range, we assume they need to be home between 8 and 8:30 pm on a school night. This immediately restricts us to about four months a year – November, December, January, and February - and when the new daylight savings time start and finish dates are introduced in 2007, we’ll be down to three months a year!

Obviously adults aren’t so restricted, and Friday and Saturday nights may extend the opportunities for youngsters.

Unfortunately, summer is seldom a good time to observe here because of cloudy – or hazy - skies and short nights when it doesn’t get really dark until as late as 10:30 pm.

The moon factor - Two days before full moon, full moon, and two days after it, observing is restricted to the moon (not too interesting at this point in its cycle), bright planets and possibly double stars. For early evening observing the moon is easiest to observe from when it is about 5 days old until it is 12 days old. However, at this time it makes observing anything else except bright planets and double stars more difficult.

For complete, up-to-date, information on speecial sky events be sure to check the this web site.