This weekend brings the night when the most Americans watch the sky: the Fourth of July, of course. When else do millions of people on lawn chairs and blankets keep staring up into deepening twilight as they wait for the show to start?

Our region has gotten into a bizarre summer weather pattern for the past 25 years, where the August 11 meteor shower is usually cloudy but the July 4 fireworks are generally clear. July 4 has been rained out only a few times in the past couple of decades, when you think about it. Of course, this year, with a wet weather pattern that more than doubled our normal June rainfall, our luck may finally be over. But if it’s clear Saturday evening at 9 p.m. before the fireworks start, what’s up while we’re waiting?

The rising gibbous Moon will hang out prominently in the southeast, in Scorpius. To its right floats the famous red supergiant Antares. But “Red Giant” is just a label: In reality its color is yellow-orange. See for yourself, near the Moon.

Next, to the left of where the sun set, only two bright-but-not-brilliant stars emerge. The one on the right is the star Regulus, marking the heart of Leo the Lion. But this star is clearly blue. What kind of heart is blue? Not good. Then, the star on the left is the planet Saturn. If you have a telescope, you’ll want to see its rings. But, hmmm…something’s very odd. There’s just a bright line across the planet. For the first time in 15 years, the rings are edgewise.

Every minute or two a point of light will drift across the heavens, because June and July are when Earth satellites get optimally illuminated after sunset. About 300 are large enough and low enough to stand out clearly. Anything that slowly moves across the sky but doesn’t have flashing aircraft strobes is one of these machines that have been circling our planet since 1957.

If you’d like to be your blanket’s resident space-satellite expert, it’s easy. Notice a few things about a particular satellite and you can tell a lot about its purpose and even whether it’s still functioning. You do have to know which way north is, however: If you face the brightest glow of twilight, north is slightly to the right of that. Evening twilight in early July isn’t in the west, but centered in the northwest.

If the gliding dot is moving south to north or vice versa, it’s in a polar orbit and is almost certainly a military spy satellite. Can it see you while you’re seeing it? Definitely. Even ten years ago, the best spy satellite, the KH-11, reportedly had a resolution of 11 inches – meaning that it can photograph your blanket and count how many people are on it. It could not tell whether or not you’re wearing glasses or whether your shoes are on or off.

If the satellite slowly changes brightness, blinking on and off, it’s tumbling out of control and no longer functioning. Most of them are like that. This one’s not watching you.

Satellites that move much more slowly than others are higher up. The ones you see orbit between about 200 and 600 miles, with the latter being the tortoises. Satellites often seem to zigzag slowly: another illusion. They travel laser-straight; imperceptible eye-muscle movements cause this effect.

If you watch the sky for half an hour, you’re likely to see a meteor or two. It might be bright and seem to come down in the next field, but it’s always at least 60 miles away. And you’re not really seeing the tiny appleseed-sized stone or ice pellet itself, but the air right around it being heated to incandescence.

In short, as we wait for the fireworks (and perhaps even what they symbolize), very little is as it seems.