Sunday Space: Could the great conjunction be the Christmas star?

About 15 minutes after sunset, from about 8.30pm to 9pm, look towards the west. You'll see two bright objects, Jupiter and Saturn, coming together in the "great conjunction"

You may have noticed that these two bright objects have been getting closer and closer over the past few months. Monday is when they are at their closest, and they will be so close, they will appear as a double star or planet.

You will have to act quick as it will be only be visible for about an hour after sunset. If you have a pair of binoculars, you can see them together in the same view.

As viewed from Earth, Saturn and Jupiter come together nearly every 20 years. However, some of these are closer together, and some are further apart. Tomorrow, they will appear closer than they have since 1226, almost 800 years.

Some have referred to this as the "Christmas star" or the "star of Bethlehem", but is it?

Johannes Kepler was a famous mathematician and astronomer whose work helped explain the orbits of planets, including events like the conjunction we are seeing tomorrow. In 1614, he calculated that Jupiter and Saturn actually had three conjunctions around 7BC, and this could be the Christmas star.

However, later calculations showed that these conjunctions were not that close, not like what we'll see tomorrow, and thus unlikely to be the special astronomical event that was noted.

There were a few other conjunctions and events around this time that could have been it. In 6BC, Jupiter, Saturn, and Mars formed a grouping on the sky that would have been a special sight. A few years later, there were conjunctions between Jupiter and Venus as well as Saturn and Venus which would have been noteworthy.

It may have not even been a conjunction. A comet - space's icy dirty snowballs that as they pass around the sun, leave beautiful tails in the sky - could have been it. Halley's comet, perhaps the most famous comet, was visible around 12BC, so probably too early. Also historically, comets were bad omens.

More space:

Others have proposed a star may have erupted or exploded, like a nova or supernova. Chinese astronomers observed a nova in the sky around 5BC, which was visible for about two months. However, records of it show that was not that obvious, probably not big enough to be that widely noticed.

We may never know what, if any, celestial event was reported as the star of Bethlehem. It may not even be one single event, but potentially multiple of these events over a period that astronomers noticed. Therefore, it is unlikely that our Great Conjunction is the same as the Christmas star. It is worth noting that late December is not linked in time of year to the Christmas star anyway.

What we do know it is an amazing event that you do not want to miss. It is our special 2020 event, and that's the way we should think about it. A special way that space is sending us off after having lived a year we'd all rather forget.