What is a Planetary Conjunction?


People here in my place saw some mysterious lights in the sky and thought they are UFOs. But my country’s astronomy agency said that those lights could be due to the planetary conjunction of Jupiter, Saturn, Mars and Neptune. I kind of know what it is after reading some info online, but I don’t know how to explain it to my father in a simple way so that he can understand.

In: Physics

A conjunction is, roughly speaking, just one planet passing by another one in the night sky. But thats not something you can really see in a single night. You would have to take a photo each day, then you can trace the movement of the planets on them.

To the layperson, a planetary conjunction would just look like two bright dots in the sky (like stars) being close to each other. Thats actually kind of the case with Jupiter and Saturn right now. But aside from that, there is nothing mysterios to be seen.

Could you explain what exactly you did see there? For example, if it moved across the sky, it certainly was not planets, but rather probably satellites. It would also help if you could tell us when this was (are we talking about “shortly after dusk” or rather “midnight”?)

As a side note, you cannot see Neptune with your bare eyes.

A conjunction is what happens when, looking at the solar system from above of below, 2 or more planets appear to line up with the sun (it only appears this way, as the planet’s orbital planes don’t line up) with respect to Earth. [You can see a diagram here](https://40c279c9-a-62cb3a1a-s-sites.googlegroups.com/site/oakastroflash/Home/the-solar-system/the-planets/planetary-motions/opposition-and-conjunction/S1_04Figure-Anno.jpg?attachauth=ANoY7cpxV36BCg2J9yB9PClD5LKhGIe8j_W6Vm_Q1kxEpsOBERm7OopUTz-ZbEdGarOTGOhtLI_ONueshrsUVkz_OLYJJFfwbZOsRjMwaL59NH3yHZ2L9ob241vDBSUl2MsPOUwB0HpvLT34GdD_SFAt2-7ZlmAcEj1RIDWSr5B5yAqYxY7P7zmmQL_UgR0ldvbz9HX7bV17tNeQoJW7O210cE_0QidxGk2vnemuBqAkAge426pbvmNFaKKV9pHndjif1TJH8pRe7Q3fgUW1eJG9__9DVvwipD8OpDhS4Zb7_mVUomIrrkrWq53b73ZYnAZXPuJMevpuyiMK3wjMi6p1FuC_TAgXbA%3D%3D&attredirects=0). The result is that, when viewed from Earth, these planets appear very close together in the sky. It’s entirely possible that this could appear to certain people as UFOs, since the result is multiple bright lights close together in the sky (especially if it’s bright planets like Jupiter and Venus), although not Neptune, as it’s not visible with the naked eye.