Peering into the mail bag

With the departure of the bright stars of winter, the relatively dim season of spring astronomy enters our viewing experience. The Sun is also setting and rising earlier which does not allow much time for any extended evening viewing -- especially with a telescope.

Aside from the Eta Aquarid meteor shower peak in the early morning of May 6 (which will be largely washed out by the rising Moon) there is not much happening astronomically. So, let's turn to the mail bag for some questions.

One question that seems to merit the most attention is, "Why can't I see a lot of stars when I first go outside in the evening?"

Good question. The answer has to do with what is called "dark adaptation." That is letting your eyes get used to seeing in the dark.

When you go outside your eyes are used to seeing in the bright light of the building interior. The pupils of your eye are too constricted to allow good seeing in the dark. Normally 15-minutes should be allowed in the dark outside before your eyes will be accustomed to seeing in the dark.

That 's why it is important to find a favorite dark-sky place where your eyes won't be bothered be any external lighting such as street or car lights. That often requires a trip outside of town. My favorite dark-sky place is about two miles outside of town on a nice hilltop that affords excellent observing in all directions.

Once your eyes have become dark adapted, you should avoid any kind of white lighting -- that includes the interior of your car. Astronomers use lighting equipment that has been either covered or coated with red. The red light will not disrupt or destroy the dark adaptation of your eyes.

Here is another good question. "How do you know all this stuff?" Hhhhmm, well, I have been doing astronomy since I was 12-years old, roughly for the last 50 years. (OK, so now you know how old I am) It is not that I know a lot, it is I have a lot of good resources that help out.

I use Astronomy and Sky and Telescope magazines (astronomy.com and skyandtelescope.com) for a lot of my information. Then there are several places on the internet I follow for information. Good charts are needed so I use skymaps.com for monthly sky maps and a listing of events.

For information on the International Space Station and space shuttle missions I use heavens-above.com or nasa.gov/multimedia and for astronomical news and events spaceweather.com.

Those are just a few. I will list more in future columns.

SKY WATCH: Last quarter moon May 6. Venus is still in the role of the evening star. This is also the time Venus is more often mistaken for a UFO. Look high in the west northwest and you won't have any problem finding it. It is above Aldebaran, the brightest star in Taurus, the Bull. If you follow a rather ragged line from Aldebaran and Venus up and slightly left to Pollux, the leftmost twin in Gemini, continue up and left through Cancer, look for Mars between Cancer and Leo, then further up to Regulus, the brightest star in Leo, the Lion.

Continue down and left to the yellow planet Saturn then further left and down to very bright Spica in Virgo. If you followed this line you are following the ecliptic, relatively the plane of our galaxy, the path the Sun follows through the sky.

On May 7 use the crescent moon to find the dim outer gas giant planet Neptune, if you are an early riser that is. The meeting of the two will be at about 4 a.m. MST. Use the moon again at 4 a.m. MST on May 9 to find two more gas giants, Jupiter and Uranus. All three will be in the same field of view in your binoculars. Although you may have to fudge a bit to the left for Uranus.

NEXT TIME: More astronomical blathering.