July 2012 Celestial Highlights

July 1 — July 20, 4:30 a.m.: Bright Jupiter and Brilliant Venus glide among the stars of the Pleiades and Hyades star clusters.

July 4, 11 p.m.: The Earth reaches its farthest point from the sun, 94.5 million miles.

July 14 and 15, 4:30 a.m.: The crescent moon joins Jupiter and Venus. Should be a very dramatic sky sight.

July 24: The crescent moon forms a distorted rectangle with Mars, Saturn, and Spica.

July 25: The moon glows to the left of Spica, forming a right triangle with it and Saturn.

The Milky Way

Scan the Milky Way with binoculars. You will be rewarded with many celestial delights: star clusters, nebulae, and dark fields that are sparse of stars next to fields full of stars.


Such is our view from Earth...

The moon guides you to Saturn

Last night the moon was just to the right of the celestial pair of Saturn and Spica. In the photo, Saturn is to the moon's upper left and Spica is to the moon's left. The moon tonight will be on the opposite side of Spica and Saturn. Look after 9:30 p.m.

A bonus body is Mars which is currently found to the far right of the moon, Spica and Saturn. In the photo it shines to the left of the tall tree. During the next seven weeks, Mars heads towards Saturn and Spica, sliding between them in mid-August.

Such is our view from Earth...

Mercury appears after sunset

Yesterday evening about 9:30, Mercury could be found to the left of the two brightest stars of Gemini, Castor and Pollux. (Pollux is the star closer to Mercury.) All three celestial lights were difficult to spot. Look closely, they were there. They will be there again tonight and the next few nights, with Mercury shining a little higher having broken the straight line it formed with the two stars.

You need clear skies and a clear west-northwestern horizon to see this.

Such is our view from Earth...

Position of Mercury

Over the next week, Mercury presents itself climbing in the west-northwest each night. Look about 9:30 p.m., or slightly before for this little star-like object shining near the true stars of Pollux and Castor in Gemini. By 10 p.m. it will have dropped to low to find. 

On June 21st, Mercury lies half way between the thin crescent moon and Pollux. Two nights later, it forms a straight line with Pollux and Castor. By July 4th, it will be lost from view as it dips quickly towards the sun.

This is tough object to spot, especially in the summer haze. Binoculars are sure to help.

Such is our view from Earth...

The Moon greets Jupiter and Venus

Tomorrow morning about 5 a.m., the thin crescent moon floats to the upper right of Jupiter. The scene may give a magical feel as the moon appears softly glowing with Earthshine, the back reflected sunlight bouncing of the nearly full Earth. Twenty-five minutes later, as the dawn brightens appreciably, Venus shines just above the eastern-northeastern horizon. It sits in our murky atmosphere about the same distance to Jupiter's lower left that the moon lies to Jupiter's upper right.

Twenty-four hours later, the moon slips directly next to Jupiter, providing an easy identification of the giant planet. As the mornings pass, both Jupiter and Venus rise higher and grow brighter becoming the dominant objects in the morning sky.

Such is our view from Earth...

Venus returns, joining Jupiter as "Morning Stars"

The early morning scene will attract skywatchers over the next month. Venus, after crossing the face of the sun during last week's transit, now can be glimpsed peeking above the eastern-northeastern horizon 30 minutes before sunrise. Be aware, though, it is difficult to spot in the bright twilight.  It may be lost in distant tree tops, due to its low elevation. That will change in the next week or so with Venus rising higher and becoming easier to see than Jupiter, which currently lies to Venus' right and much higher.

Such is our view from Earth…

Venus transit aftermath

Two days ago, Venus moved between the Earth and the sun allowing viewers on Earth to see the planet cross the face of the sun. Venus appeared as a jet black round dot about 1/30 of the sun's diameter. A few sunspots were also present at the time. (The accompanying photo also depicts wispy clouds in our atmosphere.) This sight will not be seen again on Earth for over 100 years.

Venus' true diameter is less than 1/100 that of the sun and it is more than three times closer than the sun. These two factors result in Venus appearing to be about 1/30 the diameter of the sun. 

Since Venus is about the same size as our planet, the black dot represents the apparent size of the Earth as viewed from 26 million miles away.

Such is our view from Earth...

Venus transits the sun

Tuesday evening brings a very rare planetary event to Virginia skywatchers. The planet Venus can be seen crossing the face of the sun. This event won't occur again until December 10, 2117, and then it won't be visible in Virginia. Most inferior conjunctions of Venus, those times when Venus passes between the Earth and the sun, occur when that planet passes just above or just below the sun. 

This will certainly be the year's most famous sky event that can't be seen. It can't be seen because, without the proper filters, the sun should never be viewed directly. But it is a curious event nevertheless.

Such is our view from Earth...

June 2012 Celestial Events

June 5: Venus crosses the face of the sun for a very rare transit. This should not be viewed without the proper filter: number 14 welders glass. The next one occurs on December 10, 2117, but it won't be visible from the East Coast of the US.

June 14: Earliest sunrise for observers at 40º N latitude.

June 18, 5:30 a.m.: Thin crescent Moon lies to the lower left of Venus in the east-northeast

June 20, 7:09 p.m.: Summer solstice

June 21, 9:30 p.m.:  Crescent Moon, Mercury, the bright stars Pollux and Castor appear in a row above the west-northwest horizon. 

June 27: Latest sunset for observers at 40º N latitude.

Second half of June: This will be a good time to view Mercury low in the west-northwest at 9:30 p.m. The planet will be to the left of the stars Castor and Pollux. Binoculars will be helpful picking out the little planet in the bright twilight.


Such is our view from Earth...