The wonder or sign of the woman in heaven, Re 12:1-5, appears to be going to take place in the heaven as a astrological conjunction with the sun, planets and the moon and two constellations on Sept. 23, 2017. Actually, two wonders or signs are mentioned in the following verses. The second being the great red dragon.
Revelation 12:1-3 KJVS
 And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars:  And she being with child cried, travailing in birth, and pained to be delivered.  And there appeared another wonder in heaven; and behold a great red dragon, having seven heads and ten horns, and seven crowns upon his heads.
A short video that covers the high points of the sign of the woman.
A longer video that covers the subject in greater detail.
A link to a open source astronomy software program,that can be used to verify what is shown on the video, can be downloaded here.
A review and description of the databases used in the software confirms the reliability and accuracy of the software.
Some theologians and biblical commentators say Re 12:1-5 represent Mary, and that the birth of the man child is the birth of our Lord. And that the great red dragon represents Satan using King Herod to kill the Lord as soon as he was born. Apostle John was given explicit instruction by the Lord on what he should write in the book of Revelations.
Revelation 1:11,19 KJVS
 Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea.  Write the things which thou hast seen, and the things which are, and the things which shall be hereafter;
It goes against what is written in the above verses, that Re 12:1-5 describes events in the past surrounding our Lord’s birth. John was instructed by the Lord what he was to write in the book of Revelation. He was to write the things he had seen, things which are, and things which shall be hereafter. John was not old enough to have seen the events which transpired at the time of our Lord’s birth because he was younger than Jesus. Most agree the narrative of the book of Revelation appears to be linear and that would place the 12th chapter in the future or as the Lord puts it the hereafter. Other theologians and bible commentators think that the woman is Israel, or the church but is not. According to Apostle Paul, who was highly educated as a Pharisee, and inspired by the Holy Spirit to write the bulk of the New Testament epistles, the woman who gives birth to the promise seed is Jerusalem from above or Sion, Gal 4:22-28. Which agrees with Isa 66:6-8 and He 12:22.
Isaiah 66:6-8 KJVS
 A voice of noise from the city, a voice from the temple, a voice of the Lord that rendereth recompence to his enemies.  Before she travailed, she brought forth; before her pain came, she was delivered of a man child.  Who hath heard such a thing? who hath seen such things? Shall the earth be made to bring forth in one day? or shall a nation be born at once? for as soon as Zion travailed, she brought forth her children.
Notice that as soon as Zion travailed she brought forth the children of God, the body of Christ. Verse seven closely matches the language used in Rev 12:2, and supports the fact that Rev 12:1-5 is not pointing back in time, but ahead. I recently bought the Stellarium app for my iPad to confirm the information in the videos which I linked to at the beginning of this article. From my investigations using that software, the wonder or sign of the woman as described in Re 12:1, will appear in the sky on Sept. 23, 2017. What is commonly known as the rapture, is associated with the sign of the woman, Re 12:1-5, and the woman’s birth of the man child. If so, then the rapture or gathering of the saints unto the Lord, takes place at the sounding of the seventh trumpet. I base this conclusion largely on Re 10:7 and Re 11:15
Revelation 10:7 KJVS
 But in the days of the voice of the seventh angel, when he shall begin to sound, the mystery of God should be finished, as he hath declared to his servants the prophets.
The Strong’s Concordance and Thayer definition of the Greek word translated into the English word sound in Re 10:7, means a trumpet sound. Re 10:7 refers to when the actual event takes place a short time later in the book of Revelation.
Re 11:15 And the seventh messenger trumpets. And loud voices occurred in heaven, saying, “The kingdom of this world became our Lord’s and His Christ’s, and He shall be reigning for the eons of the eons! Amen!”CLV
The mystery of God is Christ in you the hope of glory, Col 1:27, and that mystery will be finished, completed when the seventh angel sounds. Because at that point in time the body of Christ will join the head, Jesus Christ, and become His Christ. Study to show yourselves approved so as to be found worthy of the first resurrection and prepare yourselves accordingly. A couple nights ago I was playing around with the Stellarium app. I input the Sept. 23: 2017 date, and added the simulated land that forms the horizon and the sign of the woman was below the horizon in my location at that time of night. So I thought to try viewing the constellations from a different location. And then I thought, why not Israel. So I chose for the location Jerusalem in Israel, and was surprised it was one of the stored locations in the program. I looked for the Virgo constellation and panned the view around a bit, and due east came into view. The sun is just below the horizon illuminating the head of Virgo. In the app you can add or remove the simple drawn image representations of the various constellations which appear over the stars of the constellations. And the constellation Leo the lion, with the 12 crowning stars was clearly visible above her head, just at dawn. Right at due east. Of course Venus is known as the day star and is one of the planets that completes the crown of 12 stars. Fittingly enough the brightest of all the stars in the twelve star crown. The time when I saw this was around 22 07 10, in the time field setting in the software. Two scriptures came to mind, so I looked them up with my bible app. I felt the Spirit of the Lord move on me as I read them.
Matthew 24:27 KJVS
 For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be.
2 Peter 1:19 KJVS
 We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts:
It occurs to me that scriptures in Daniel and Revelation may shed light on the recent ability of being able to predict this future sign in the heavens taking place on a specific date using astronomy software. Which of course was impossible before computers were invented.
Daniel 12:4 KJVS
 But thou, O Daniel, shut up the words, and seal the book, even to the time of the end: many shall run to and fro, and knowledge shall be increased.
Revelation 10:4 KJVS
 And when the seven thunders had uttered their voices, I was about to write: and I heard a voice from heaven saying unto me, Seal up those things which the seven thunders uttered, and write them not.
It is only with the increase of knowledge in computer and software technologies, that this particular alignment of planets, the sun and moon in conjunction with the two constellations was discovered. This sign speaks of troubling and chaotic times ahead. Some suggest that the sign of the red dragon could represent a large inbound brown dwarf star and planets with moon which could be responsible for the catastrophic disasters contained in the book of Revelation before and after the 12th chapter of Revelation. Since great suffering is on the horizon for the seed of the woman. I think it is fitting that this website’s main subject matter, is the role suffering plays in being conformed to the image of Christ.