About Bob Riddle

Currently: Retired from the physical classroom (May 2017) but not yet finished learning and teaching. Column Editor, Scope on the Skies - Science Scope Magazine; NASA/JPL Solar System Educator Program - Solar System Ambassador Program, and Solar System Ambassadors Program.

Venus at Inferior Conjunction – 2020

   Wednesday June 3rd the inner planet Venus reaches its orbital position known as inferior conjunction.
   This is one of four points along an inner planet orbit. At inferior conjunction Venus is between the Earth and the Sun – sort of like our new Moon phase – but not necessarily directly in line. If that were so, inferior conjunction at the same time as Venus in direct line with the Earth and Sun (a node crossing at inferior conjunction) it would be a somewhat rare transit of the Sun by Venus. These happen as a pair of transits about one time each century with the last pair of Venus transits in June 2004 and June 2012. Here are some pictures of the June 2012 Venus Transit. Here is a link to the Vimeo web site to watch a video of the 2012 Venus Transit.
   By the way the next pair of Venus Transits are December 2117, and December 2125.


    At this inferior conjunction Venus is 0.19o north of the ecliptic.

   
   
   
   

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.


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Moon – Spica Conjunction

   Tuesday evening the 10.5-day old waxing gibbous Moon will be about 5-6o from the blue-white star Spica in the constellation Virgo the Harvest Maiden. Both will fit within the field of view of binoculars.


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.


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Mars – Saturn Heliocentric Conjunction – 2020

   Monday June 1st two of the outer planets, Mars and Saturn, will be more or less at the same heliocentric longitude of about 280o, and would be in what is called a heliocentric conjunction. Heliocentric (Sun-centered) coordinates uses an overhead view of the solar system with planet location given as degrees of heliocentric longitude. The heliocentric longitude is based on a view from the Sun and is given as the angle between a planet and the vernal equinox. The vernal equinox, 0o, is located within the constellation of Pisces the Fishes, and is the intersection between the ecliptic and the celestial equator.
   As the Earth revolves around the Sun it ‘gives’ the Sun its apparent motion eastward along the ecliptic. When the Sun crosses the celestial equator at this intersection it is moving north. At the crossing northern hemisphere winter becomes spring – the opposite seasonal change for the southern hemisphere.

   Despite having the same heliocentric longitude, when viewed from the surface of the Earth, the two show an east to west difference of about 2 hours of right ascension.

   
   
   

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.


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June Qué tal in the Current Skies Now Available

   This month, June, planet viewing is best in the early morning hours before sunrise. With the exception of Mercury all of the visible planets are in the morning skies. Mercury moves out east from the Sun this month reaching its greatest eastern elongation and then rather quickly moves westward back to the Sun and inferior conjunction on July 1st.
   This month there will be a pair of eclipses staring with a Penumbral Lunar Eclipse on the 5th. As penumbral eclipses go this one will be barely visible as it occurs over parts of southern Europe, Africa, south Asia, and Australia. On the 21st the new Moon will pass across the Sun setting up an annular solar eclipse that will occur over parts of north Africa, the Middle East and Southeast Asia.
   And on the 20th the Sun crosses the ecliptic moving north starting Northern Hemisphere summer and southern Hemisphere Winter.
   Click here to go to the Qué tal web site.
   

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.


Also Follow me and other great resources at Feedspot.

Moon on the Move

   Over the next several days the Moon, as it waxes toward first quarter, will be moving toward the east and as it does the Moon will pass by several of the brighter stars along the Moon’s orbital path. This will take the Moon near Pollux, one of the Gemini ‘Twins’, and then past Regulus, the ‘Heart’ of Leo the Lion. On the 27th you may be able to see the open star cluster, M-44, or also known as the Beehive Cluster.



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.


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Thin Waxing Crescent Moon Near Venus – Mercury

   Saturday evening May 23rd look toward the western horizon for the very thin young 1.3-day old waxing crescent Moon. The Moon will be about 3-4o from the inner planet Venus and about 5-6o from the other inner planet Mercury. All three will easily fit within the field of view of binoculars and given the range of apparent magnitudes should make for a great view and even a picture.
   Apparent MagnitudesWaxing Crescent Moon: -8.42 Venus:-4.16 Mercury: -0.42
   
   
   
   
   
   

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.


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The Inner Planets Meet

   Thursday evening May 21st, shortly after sunset, the two inner planets Mercury (apparent magnitude 0.41) and Venus (apparent magnitude -4.16) will be about 1o from each other. Both planets will fit within the 7o field of view of 7×50 binoculars as the graphics below show. Both planets are in motion along their respective orbital paths with Mercury moving toward the east while Venus is moving toward the west.


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.


Also Follow me and other great resources at Feedspot.