Astronomical Potpourri in July

July 2009  :  Dave Huestis

Note: This article may contain outdated information

This article was published in the July 2009 issue of The Skyscraper and likely contains some information that was pertinent only for that month. It is being provided here for historical reference only.

Not that you would notice, but the Earth is at its farthest distance (94,508,863 miles) from the Sun during 2009 at approximately 10:00 pm EDT on July 3. Back on January 4th, the Earth was at its closest distance from the Sun for the year, a mere 91,404,995 miles. That difference is just over 3 million miles. This variance is the result of the Earth’s elliptical, not circular, orbit about the Sun.

Something you might have noticed from time-to-time is that each Full Moon may look larger or smaller in our sky. It’s no atmospheric trick. The Moon’s distance from the Earth varies as well. On the 7th the Full Moon will be its smallest for 2009, since it will be 252,433 miles from the Earth. The largest Full Moon for 2009 occurred back on January 10th when it was at its closest distance to the Earth, 222,149 miles. Try to get a digital image of the Full Moon each month and compare your images side by side on your computer screen. You’ll be amazed by the amount of change in apparent size.

Be sure to watch the news media on July 22 for images of the total solar eclipse which will occur over India, China and the Pacific Ocean. Totality lasts for a maximum of six minutes and 39 seconds (the longest duration of totality this century) east of Iwo Jima. Shanghai residents will see about five minutes of totality. I’m hoping one of my Bryant University astronomy lab students, who lives in Shanghai, will send me an image or two.

And finally, during the last four days (28-31) of July there are two minor meteor showers, the Delta Aquarids (medium speed) and the Alpha Capricornids (slow with occasional fireballs). Once the Moon sets around midnight one can expect to see perhaps ten or fewer meteors per hour if you look towards the south. You might even spot a few early Perseids, which reach peak activity in mid-August, in the northeastern sky

Visit Seagrave Memorial Observatory on Peeptoad Road in North Scituate any clear Saturday night and let our volunteers share their love of the heavens with you. Check the Skyscrapers website www.theskyscrapers.org for our summer month schedule. Admission is free.

Keep your eyes to the skies, and the next time you look up at the Moon, remember the men who first walked upon its surface 40 years ago.