Marvelous nights for a moon dance
This summer's moon should seem to whirl around Jupiter and Mars
Summer is here in the Northern Hemisphere. Nights may be shorter but temperatures lend themselves to stargazing. Besides clouds, mosquitoes, and light pollution, nothing stands in the way of a good long gaze at the majesty and wonder of the night sky. (You can make up for lost sleep at the beach.)
July will begin and end with Jupiter, the solar system's gas giant, presenting great views in tandem with a crescent moon.
About 9 p.m. on July 1, 2, 3, and 4, look west-northwest and you'll see the duo. On the first of the month the moon will be east of Jupiter, on the 2nd it will hover just above the regal planet, and on the 3rd and 4th it will appear to the planet's west. Because its orbit is so much shorter and closer to Earth than that of the planets, the moon will appear to speed past them.
The month's final nights end with Mercury tiptoeing past Jupiter low on the western horizon right at sunset. July 30 offers a particular treat as a thin crescent moon will rest between the two planets about half an hour after sunset.
And speaking of the movers and shakers of classical mythology, Mars, too, will be worth watching this month. On the morning of July 17, hope for a clear sky just before sunrise: Mars and a near-full moon will seem to touch, with the moon even occulting (blocking) Mars for some observers in parts of Florida.
Mars will come closer this summer to Earth than at any time in recorded history. Astronomy Magazine jokingly notes, "you can bet UFO sightings will be on the rise," thanks to the planet's rusty-red brightness. Mars will hang relatively low in the sky in July, rising each night around 11 p.m., a manageable time.
But Mars won't be the only red-gold light in the sky this summer. Astronomy Magazine's Bob Berman makes some telling points in the July issue about why summer moons look fainter and more orange than the bright white moons of December.
"Summer air typically has 10 to 15 times more water vapor than winter's," he writes. Combine that with a low angle of view, which adds six times more air to see through, then throw in "dust, crud, and humidity," and the moon takes on a "honey colored" hue.
But oh, the enchanting light cast by a summer moon.