I think the 9/23/17 “sign” has been debunked because it is neither rare nor very symbolic from an astronomical perspective when you actually look at the data:
http://thechristmasstar.org/wp-content/uploads/2017/07/TheSignofRevelation12.pdf
For example,
(1) the sign is not even visible to the naked eye.
(2) To determine how rare the 23 September 2017 configuration actually might be, look at the 21 years of the sign’s appearance between 2000 and 2020. Since the sign frequently appears during the Jewish holy day of Rosh Hashana, those dates are included (in the link above), along with the date of the event (Virgo clothed with the sun, with the moon at her feet), the location of the sun in Virgo, the type of moon at Virgo’s feet, and the number of planets in both Virgo and Leo when the sign appears.
Interestingly, during the 21 year period, the sign appeared seven times on Rosh Hashana (year in bold print), seven times on the day after Rosh Hashana and seven times a full month after Rosh Hashana.
(3) Because Mercury is so close to the sun, it will always be present when the sun is located in Virgo. Being the next closest planet to the sun, Venus will normally appear in Leo, Virgo or Libra when the sign appears (10 times in Virgo or Leo in the 21 years). Mars passes through Virgo about once every 2 years and appears four times in Virgo during the period; Jupiter passes through Virgo and makes one to two appearances in the constellation every 12 years. Saturn will spend 4 or 5 years in Virgo about every 27 years.
Thus, the appearance of multiple planets in the two constellations when the sign appears is common, not unusual. Proponents for the sign claim that the appearance of four planets in the two constellations in 2017 is extremely rare. But, as can be seen in the table, four planets appeared in the two constellations in 2008, 2015 and 2017, and in 2008 the sign appeared during Rosh Hashana. The number of planets in the two constellations in conjunction with the sign’s appearance for the 21 year period is as follows: 1 planet = 2 times; 2 planets = 8 times; 3 planets = 8 times; 4 planets = 3 times. Four planets appearing in the two constellations is not an “extremely” rare occurrence.