According to Webster’s, a conjunction is several things, but in an astronomical sense, a conjunction is; a : the apparent meeting or passing of two or more celestial bodies in the same degree of the zodiac… or; b : a configuration in which two celestial bodies have their least apparent separation…
In the southwestern skies just after darkness has fallen, it’s hard to miss the two blazing orbs that are slowly coming together night-by-night. These are Venus, the brighter one on the right (to the west) and Jupiter, the more southerly one. Jupiter has been in the southern sky all summer and fall, and it’s still about as bright now as it was at the beginning of summer. Venus, on the other hand, has recently rounded the back side of our Sun and is on an approach with us that causes it to both increase in brightness as it gets closer, and, allows it to come to conjunction with other celestial bodies as it does so.
Venus is more than 5 times closer to us than Jupiter which is why it shines more brightly. Due to our solar system being laid out in a flat plane, there are frequent opportunities for two or more objects to pass close to one another. Our moon comes into conjunction with every other celestial orb once a month, but two planets reach conjunction with one another more rarely. Since the two brightest planets in our sky are currently approaching a conjunction on November 30, now is an ideal time to step outside on any clear night for the next 3 weeks to watch it all happen. On December 1, the moon will join the bright pair for what’s called a “Grand Conjunction” and provides us an excellent chance to take your own picture of a really memorable sight. A less dramatic conjunction occurs on December 29 when Jupiter is joined by Mercury in the evening sky, not long before the giant planet is lost behind the glare of the Sun when Jupiter reaches what’s called “superior conjunction”. The moon once again joins this pair that night to help point the way to finding them.
Watch each night as Jupiter continues westward, passing by Venus at the end of November and the beginning of December. Reports of UFO’s nearly always increase when these conjunctions occur, and the local news stations will likely get a few calls about that time. But remind yourself what’s going on as the picture changes night-by-night, too. Venus is approaching at the same time that Jupiter is receding away, and its only because we’re all on a flat plane that this all even has a chance to take place after all. At the same time, remind yourself that astronomy is NOT astrology. Nothing that’s happening as one planet passes by another has anything to do with anything in our lives, and its disturbing (at least for me, personally) to know that so many people think there’s some magical connectedness between the planets in their orbits and our individual lives on the 3rd rock from the Sun. But that’s what AOAS is here for, after all….to help educate everyone about the silliness and absolute absurdity of astrology, while helping everyone we meet understand a tiny bit about the wonders of our universe, and the differences between the science, and the pseudoscience.
It’s going to be a pretty occurrence happening between these two bright star-like objects in our nighttime sky over the next few weeks. Dress warmly and get out and try to enjoy it whenever you can.
Capturing Conjunctions (and other celestial events) in Pictures
Certain things are absolutely required for taking a picture of a celestial scene. A camera that can be used to take long exposures and a way to hold open the camera shutter for as long as may be required, and a tripod to hold everything perfectly still while the image is being taken. Cameras using film are in some ways easier to use since you just need a roll of around 200 ASA to 400 ASA film, a manual setting on the body of the SLR camera, a cable release and the tripod. Setup the equipment, find the subject and compose the shot, then use the cable release to open the shutter for between about 2 seconds and 5 seconds, or even up to 10-12 seconds…take several shots of slightly increasing lengths each and you’ll be glad you did. Subtle differences will be brought out in each image after processing and more than one might be very special to you.
Digital cameras need the capability for taking shots of at least 2 seconds but a minimum of 4 seconds would be better as a starting point, and increasing the lengths by a couple seconds for each exposure up to 10-12 seconds each. You’ll need to manually set the camera for shots to be equal to film speeds of 200 ISO to 400 ISO, too. Just make certain that you don’t forget the tripod and a cable release, or, use the auto timer for starting you’re exposures to keep the tripod from jiggling. Please note that if you want to take shots of dimmer objects, say, the Milky Way, you need to increase your exposure times to at least 30-45 seconds. You’ll need a dark-sky location for dimmer scenes as well, so plan ahead. Planets are bright and only need the exposure lengths I’ve listed above for good results.