On Tuesday, October 10, 2023, you possibly can see a stunning conjunction within the morning sky. The dazzling planet Venus and vivid star Regulus – Coronary heart of the Lion in Leo – will meet on the sky’s dome. By coincidence, the waning moon can be seen that morning additionally! What an excellent sight within the east earlier than daybreak!
Technically talking, objects are stated to be in conjunction once they have the identical right ascension – form of like celestial longitude – on our sky’s dome. Virtually talking, objects in conjunction will probably be seen close to one another for some days. So be sure you look ahead to Venus and Regulus on the times earlier than and after the October 10 conjunction, too.
What’s a conjunction?
Sometimes, two or extra objects meet up with one another in our sky. Astronomers use the phrase conjunction to explain these conferences. The phrase conjunction comes from Latin, that means to affix collectively. Perhaps you keep in mind the outdated Conjunction Junction cartoons from the Nineteen Seventies. In language, conjunctions relate to clauses introduced along with phrases like and. In astronomy, conjunctions relate to 2 or extra objects introduced collectively within the sky.
Typically one among these objects is the sun, so the conjunction can’t be seen. However different conjunctions – between stars, our moon, and the planets – will be actually spectacular.
You may’t see an inferior conjunction
An inferior conjunction is when an object passes between us and the sun. Any object that orbits the sun nearer than Earth does would possibly go by way of inferior conjunction once in a while. That’s, assuming its orbit lies kind of near the ecliptic.
Often, although, when astronomers communicate of an inferior conjunction, they’re speaking about Venus or Mercury, which orbit between Earth and the sun. Astronomers typically consult with Venus and Mercury as inferior planets. Once they’re at or close to inferior conjunction, we typically can’t see them. They’re hidden within the sun’s glare. Sometimes, although, Venus or Mercury at inferior conjunction will be seen to transit throughout the sun’s disk.
We shouldn’t overlook the moon right here. It passes between Earth and the sun at new moon as soon as every month. Due to this fact it could be appropriate, if slightly uncommon, to say that the moon is at inferior conjunction when it’s at its new phase.
You may’t see a superior conjunction both
A superior conjunction is when an object passes behind the sun from our standpoint. Take a look at Venus’ orbit above. Half of its conjunctions with the sun – once they come collectively on our sky’s dome – are inferior conjunctions, and half are superior conjunctions. It’s enjoyable to think about the inferior planets on an infinite cycle of passing in entrance of the sun, as seen from Earth, then behind it, and again once more, like squirrels operating round a tree.
In the meantime, the superior planets – or planets farther from the sun than Earth – can by no means be at inferior conjunction. Mars, Jupiter, Saturn, Uranus and Neptune can by no means go between us and the sun. So the superior planets solely have superior conjunctions.
However different conjunctions can look lovely
The commonest – and most enjoyable – sort of conjunction doesn’t contain the sun. Any time two objects go one another on the sky’s dome, they’re stated to be at conjunction. These kinds of conjunctions – perhaps between two planets, or a planet and a star, or a star and the moon – occur a number of occasions each month. They’re lovely. The view can cease you in your tracks.
For instance, for those who have been lucky sufficient to have appeared on the moon on July 21, 1969, as Neil Armstrong and Buzz Aldrin headed residence from the Sea of Tranquility, you’d have seen the moon in conjunction with Spica, the brightest star within the constellation Virgo. They have been solely about two degrees aside that night time. That’s a bit greater than the width of your index finger held out at arm’s size.
There are all the time a couple of significantly good conjunctions yearly. On March 1-2 2023, we have been handled to a spectacular conjunction between vivid planets Venus and Jupiter, as you possibly can see under. Click here to see a full gallery of Venus-Jupiter conjunction images captured by members of the EarthSky group.
Look ahead to and revel in conjunctions
Folks usually take into consideration the night time sky as being everlasting and unchanging, not less than on a human scale. In case you watch the skies usually, although, you’ve absolutely seen that’s not true. The celebrities don’t transfer relative to one another, however they do transfer throughout the sky over the course of a single night time, as Earth spins below the sky. And, from one night time to the following, every star rises and units 4 minutes earlier every day, as Earth strikes across the sun.
When you’ve discovered the ecliptic, you possibly can see the place the true motion is. As a result of they’re comparatively near us, the planets and moon do transfer relative to one another and the celebrities, and shortly, from our standpoint. They alter their positions, seem to maneuver nearer collectively and father aside, and typically go by one another within the sky, coming to conjunction. Of the entire pleasures of stargazing, seeing this motion of our nearest neighbors is among the biggest.
Keep updated with upcoming conjunctions by way of EarthSky’s night sky guide.
Backside line: A conjunction is when two objects are shut collectively on our sky’s dome. Some conjunctions can’t be seen, however others look spectacular.
