10/21/2022 – Ephemeris – Lots of transient astronomical activity this weekend

This is Bob Moler with Ephemeris for Friday, October 21st. Today the Sun will be up for 10 hours and 41 minutes, setting at 6:48, and it will rise tomorrow at 8:07. The Moon, halfway from last quarter to new, will rise at 4:44 tomorrow morning. | We have several astronomical events happening tonight and over the weekend. The Orionid meteor shower may still be at peak, appearing tonight between 11 pm and moonrise tomorrow morning. Up to 20, and maybe more, meteors per hour may be spotted just prior to moonrise. Tomorrow Venus will be in superior conjunction with the Sun, the passing behind, though not directly behind the Sun, and thus entering the evening sky. It will be a month or so for Venus to separate itself from the Sun’s glare to be spotted in the early evening. Finally, on Sunday Saturn will end its retrograde or westward movement against the stars of Capricornus and resume moving eastward, its normal motion around our sky.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The Orionid meteor shower radiant. The radiant rises at 11 p.m., so the meteors will be visible from then into morning twilight. Despite the location of the radiant, the meteors will b e seen all over the sky. However, true Orionids can be traced back to the radiant point. This chart is from another year. This year, bright Mars would be at the top center of the image. Created using Stellarium.

Venus near Superior conjunction through the Solar and Heliospheric Observatory (SOHO) LASCO C2 Coronagraph. The white circle inside the occulting disk is the diameter of the Sun’s photosphere, the disk we see of the Sun in white light. Launched in 1995, SOHO has been in halo orbit around the Sun-Earth L1 Lagrange point ever since.

Saturn stationary animation showing it with and without annotations. The fine, folded line with tick marks is Saturn’s path. The tick marks are at 10-day intervals. Saturn starts out in retrograde motion, heading westward or to the right. On October 23rd, it slows and stops that motion. It begins to head back eastward in its normal prograde motion to the left. Outer planets like Saturn, Jupiter, Mars and the rest exhibit retrograde motion when the Earth in effect passes them on the same side of the Sun. Click on the image to enlarge it slightly. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw, and GIMP.

06/06/2016 – Ephemeris – Venus passes behind the Sun today

Ephemeris for Monday, June 6th.  Today the Sun will be up for 15 hours and 27 minutes, setting at 9:25, and it will rise tomorrow at 5:57.  The Moon, 2 days past new, will set at 10:52 this evening.

Today the planet Venus will be in superior conjunction with the Sun, and indeed will pass directly behind the Sun.  That event will be completely unobservable due to the Sun’s brilliance.  Fours years ago we observed the transit of Venus across the Sun.  June 6, 2012.  It got me thinking.  Transits of Venus occur in pairs 8 years apart followed by a very long interval of over 100 years.  It turns out the Venus orbits the Sun 13 times in approximately the same time that the earth orbits the Sun 8 times.  In 4 years Venus goes around the Sun 6 ½ times and put’s Venus behind the Sun 4 years after 2012.  Today to be precise.  In another 4 years we’ll have Venus between the Earth and the Sun again, except Venus will be a bit too far north to transit the Sun.

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

Addendum

SOlar and Heliospheric Observatory (SOHO) stationed at the Earth-Sun Lagrangian point 1 (L1) a million miles sunward of the Earth. Sent back this animated GIF of Venus approaching the Sun in the last few days. In the LASCO C2 coronagraph the large disk at the center blocks the brightest part of the Sun’s image. The white circle represents the Sun’s disk size. Credit ESA/NASA.