Thursday evening August 24th the waxing crescent Moon passes by the outer gas giant planet Jupiter, and then on Friday evening August 25th the waxing crescent Moon passes by the gas-composed bluish-white star star Spica in the constellation Virgo the Harvest Maiden.
Our Moon reaches perigee, (closest distance to Earth), for this orbit on Friday August 18th. At that time the Moon will be at a distance of 28.70 Earth diameters (366,121 km or 227,497 miles) from the Earth.
Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*
On the day of the perigee Moon the 26-day old thin waning crescent Moon is above the eastern horizon about 30 minutes to an hour before the Sun rises. The inner planet Venus (-3.97 apparent magnitude) is within about 9o from the Moon while the Dwarf Planet Ceres, at an apparent 8th magnitude is too dim to be visible to the naked eye, is about 8o from the Moon.
Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”
Wednesday morning August 16th the 24-day old waning crescent Moon is within 2-3o from the reddish star Aldebaran and the rest of the stars of the open star cluster the Hyades, forming the v-shaped face of Taurus the Bull.
With 10×50 binoculars the Hyades and the Moon will all fit within the field of view as this graphic is showing.
Tuesday morning, August 15th the 23-day old first quarter Moon will be the point of a celestial triangle with the two open star clusters, the Pleiades, and the Hyades as this graphic shows. The v-shaped Hyades forms the face of Taurus the Bull while the ‘dipper-shaped’ Pleiades lies along the Bull’s shoulder. Both open star clusters are about 8o from the Moon.
Ok, so how can you Moon Uranus? Yeah I know – a sad, and bad joke. Let’s put it behind us.
Sunday morning, August 13th, the 21-day old waning gibbous Moon rises within a few degrees from the planet Uranus. Both are within the eastern fish of the constellation Pisces the Fishes. Uranus ‘shines’ at just under 6th magnitude so it is possible to see the 7th main planet from the Sun with binoculars. However the reflected light from the Moon will brighten the sky more than enough to drown out the dimmer light from Uranus and most other stars in the area making them not visible.
Not that it will be visible but near the Moon on the opposite side from Uranus is one of the dwarf planets, Eris. However at nearly 19th magnitude and almost 95.729 AU, (8,898,566,474 miles ; 14,320,854,563 km) from the Earth it is all but impossible to see without some serious amateur equipment, at an observatory, or with the Hubble Telescope. Add approximately an additional 1 AU (93,000,000 miles; 1,496,68992,000 km) to get its distance from the Sun.
What did I say about enough of the ‘bad jokes’? This cartoon reminded me of the statement, “Captain, We’re orbiting Uranus searching for Klingons.”
Speaking of Uranus here is a portion of the Orbits performance video showing Uranus and some of its moons.
Monday August 7th the full Moon, just one day before it will be at descending node, passes through the Earth’s outer shadow and briefly crosses through part of the darker inner shadow, the umbra. This sets up a partial lunar eclipse.
The Earth has two distinct shadows, an inner and much darker umbra, and the outer and fainter penumbra as this NASA graphic shows.
This eclipse will not be visible across the continental United States.
For additional information about this or other eclipses go to the Hermit Eclipse web site.
In reality this year’s annual Perseid Meteor shower will be affected by the Moon. The waning gibbous Moon will rise at about the same time as the constellation Perseus – the location for the meteors. With the bright reflected light from the Moon it will be nearly impossible to see any meteors.
Also keep in mind that the numbers quoted for meteors per hour, the ‘ZHR’ or Zenith Hourly Rate, is an average not a guarantee that you will see that many. On a good peak night in some years I have seen 30 or 40 bright meteors per hour from dark skies. The best time is the few hours before sunrise as the Earth rotates your location into the direction the Earth is moving and sort of puts you face-on into the meteors.
(graphic source from Facebook with this URL: http://sci-techuniverse.com/) — link takes you to a non-existent web site, or to a Go-Daddy advertisement
Update: I did a search for the web site and found that the correct address is http://www.sci-techuniverse.com/, and after searching the web site I could not find this graphic. There is, however a write-up from last year about the Perseids.
The peak time for the Perseids is August 12th and 13th but more specifically during the predawn hours of the 13th as the constellation Perseus is rising.
Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.