05/19/2020 – Ephemeris – Venus will leave the evening sky in 15 days

This is Ephemeris for Tuesday, May 19th. Today the Sun will be up for 14 hours and 59 minutes, setting at 9:09, and it will rise tomorrow at 6:08. The Moon, 3 days before new, will rise at 5:25 tomorrow morning.

In 15 days Venus will leave the evening sky by passing between the Earth and the Sun in what astronomers call an inferior conjunction. Eight years ago, June 6th 2012, Venus went through another inferior conjunction. That time it passed directly between the Earth and the Sun so we could see the black spot that was Venus cross the face of the Sun as a rare Transit of Venus. Eight years before that, on June 8th 2004, we had another transit. However we will not see another in our lifetimes. The next one will occur in 2117. With the June 3rd conjunction Venus will pass north of the Sun from our vantage point, since Venus’ orbit is tilted a bit more than 3 degrees to the Earth’s orbit. So enjoy Venus while you can, unless you want to get up really early next month.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Transits of Venus-Two hits and a miss. Image created using Cartes du Ciel (Sky Charts).

Earth and Venus have a 13:8 orbital resonance.  That is Venus orbits the Sun 13 times in the same time that the Earth orbits the Sun  8 times. So Venus has the same position in our skies it had 8 years ago.  Actually the resonance is not perfect The resonance comes out 2.4 days short. So events like inferior conjunctions like the ones in the example above back track two and a fraction days from the 8 year interval.

Venus goes through a 584 day cycle from one inferior conjunction to the next.  Five of those cycles equals 7.994 years. The Maya were well aware of this and one of their calendars was based on the Venus-Earth relationship.

10/26/2018 – Ephemeris – Venus passes inferior conjunction with the Sun today

Ephemeris for Friday, October 26th. The Sun will rise at 8:12. It’ll be up for 10 hours and 27 minutes, setting at 6:40. The Moon, 2 days past full, will rise at 8:19 this evening.

Later this morning the planet Venus will pass in inferior conjunction with the Sun, moving officially from the evening sky to the morning sky. Inferior conjunctions are when Venus is between the Earth and the Sun. We haven’t seen Venus for over a month, it setting too soon after the Sun to be spotted. It’s appearance in the morning sky will be much more sudden. On fall mornings the ecliptic, the path of the Sun and most planets is more vertical in the sky, opposite that of the evning sky, so that Venus will suddenly appear. Being south of the Sun, it will take 3 days, next Monday morning to rise with the Sun, but after that Venus will rise 8 minutes earlier each morning for a while. It should be easily visible in two weeks as the bright Morning Star

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Venus and the Sun recorded by the Solar & Heliospheric Observatory (SOHO) LASCO C3 coronagraph less than 24 hours before the actual instant of Inferior conjunction. Credit: ESA/NASA.

01/10/2014 – Ephemeris – Venus will pass inferior conjunction with the sun tomorrow.

Ephemeris for Friday, January 10th.  The sun will rise at 8:18.  It’ll be up for 9 hours and 4 minutes, setting at 5:22.   The moon, 3 days past first quarter, will set at 4:19 tomorrow morning.

Tomorrow what has been our evening star during summer an autumn will pass between the Earth and the Sun and will enter the morning sky, where sharp-eyed observers will pick it up just before sunrise.  That passage is called inferior conjunction, because Venus moves between the Earth and the Sun.  Venus and Mercury are called inferior planets, not because of their quality, but because they orbit inside the earth’s orbit.  Mars through Neptune are then of course superior planets.  The last time Venus passed inferior conjunction, on June 5th, 2012 it passed directly in front of the sun in a rare transit.  This time it will be north of the sun by about 5 angular degrees.   There’s only a hundred and four years before the next transit.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum

Gary Carlisle’s photo of the transit of Venus, June 5, 2012..