May 16, 2024

AstroCal – June 2024


     Okay, so we had a winter with very little snow (about one quarter of our yearly average in the Ontonagon area).  As of mid-May, we have only been playing hide and seek with warmer weather making one wonder if spring will also be AWOL this year.  The only thing we can say with any certainty is that the official kick off of summer, the Summer Solstice, will take place on June 20 at 4:51 EDT.  Will summer-like conditions commence on that date?  At the solstice, the Sun’s Vertical Ray reaches as far north as it will get.  Thanks to the title of the Earth’s axis, people living along the Tropic of Cancer (23.5 degrees N latitude) will see the Sun directly overhead while those of us living in the mid-northern latitudes will see it at its highest point in our southern sky.  With the higher sun angle and daylight stretching to 17 hours per day, people wonder why it takes about a month longer for the truly warm summer to arrive.  

     The northern hemisphere needs some time to absorb enough energy for the temperatures to catch up with the season.  Along the south shore of Lake Superior, we have another temperature regulating factor.  Water takes longer to warm up than the land, therefore the big lake keeps the temperatures lower near the shore for a longer stretch of time.  When I was still teaching, it was not uncommon to see students arriving at school in late May or early June wearing shorts.  They would leave home from Mass City, Greenland, and Rockland on a balmy 70 degree F day only to reach Ontonagon and an unpleasant surprise.  The cold lake water and frequent NW winds would lower the temperature at the school into the high 50 degree F range.  Just the opposite happens in the fall when the Lake Superior temperatures stave off an earlier frost because Superior cools off slower than the land.  Those in the know say some of the best Lake Superior swimming happens in the fall when the air is cool but the water temperature is still quite balmy.

     June begins with the end of a Lunar Cycle which will present an old Crescent Moon in the ENE in the hour before sunrise.  The New Moon begins the new cycle on June 6, followed by the young Crescent Moon that sharp eyed observers will be able to see low in the WNW an hour after sunset.  The First Quarter (June 14), Full Moon (June 21) and the Last Quarter Moon (June 28) wrap up the Lunar viewing for the month,  Lunar Perigee takes place on June 2 when the Moon will be 228,727 miles from Earth and the Lunar Apogee of 229,463 miles will occur at 8 a.m. EDT on June 27.

     Mercury will be in superior conjunction with the Sun before finally emerging during the last week of June.  Look just left of Pollux and Castor, the Twin Stars in Gemini, the Twins.  Mercury will be low in the WNW sky 40 minutes after sunset and those two familiar stars will be your guide to finding it.  No other bright planets will be visible in the evening sky during June.

     Morning planets will offer a little more variety.  Saturn will be located in the SE at dawn and the Rings will be tilted at 2 degrees from edge on.  Though the Rings will seem to disappear when a Ring Crossing occurs in March of 2025, the planet will be too close to the Sun to observe this edge on presentation.  The next favorable Ring Crossing will not happen again until 2038.  In May of 2032, the Rings will open up to their maximum viewing angle of 26.8 degrees making the much easier to see in the years before that date.  On June 30, Saturn will appear to be stationary before beginning retrograde motion.  Saturn will appear to travel backwards against the background stars until November.  This is an illusion caused by the Earth’s faster revolution around the Sun – as we pass Saturn’s orbit, it appears to reverse course.

     Mars, at Mag +1.0 in the east at dawn.  The Red Planet will be 173 million miles (1.86 a.u.) from the Earth on June 1 and this distance will decrease to 162 million miles (1.72 a.u.) by the end of the month.  The angular size of the planet will increase from 5.0 arcseconds to 5.4 arcseconds during this time.  Look for Jupiter to join the morning sky at mid-month.  Each morning, this Gas-Giant will rise a little higher above the ENE horizon just below the Pleiades Star Cluster (also known as the Seven Sisters) in Taurus, the Bull.  Binoculars will be needed to  find Uranus shining at Mag +5.8 halfway between Jupiter and Mars.  Larger binoculars will be needed to find Neptune in Pisces, the Fish.  Locate Neptune just left of the  small rectangle of stars P27, 29, 30 and 33 in Pisces – it will be a faint Mag +7.8.  On June 28, Neptune will be very near the upper limb of the waning Quarter Moon.

     As long as we mentioned the Pleiades, there is an interesting anecdote that says some ancient people used the cluster as a type of lie detector.  In that there are only six visible stars in the group, anyone who said they could see seven was obviously not trustworthy.  Another school of thought postulates there was a seventh start visible in ancient times but it faded from view for some unknown reason.  If one has noticed the shape of the logo used for Subaru automobiles, then you have seen a more modern interpretation of the Pleiades star cluster.     

Compiled by Ken Raisanen of WOAS-FM – information provided by Abrams Planetarium Sky Calendar, Michigan State University.  More information and subscription information can be found on their website at or on X (formerly Twitter) at  Yearly subscriptions cost $12 and can be started anytime.


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