A rare alignment of 7 planets is about to take place
sciencealert.com185 points by koolba 4 days ago
185 points by koolba 4 days ago
Apparently this is visible everywhere on Earth, which is cool. (Sometimes sites don't bother saying where and it turns out to only be visible in the US - very annoying for those who live elsewhere.)
Makes sense because the planets are so far away that a different viewpoint on earth won't make a noticeable difference. Unlike for the moon. This is why lunar eclipses are the ones that are only visible in certain places.
I don't think it is simply the "planets are so far away" that allows this to be visible from everywhere on earth. Stars are very far away compared to planets, and that distance makes them only visible from certain hemispheres (certain stars are only visible from certain hemispheres). I believe the fact that the planets are all on the ecliptic is what makes the alignments visible worldwide.
Plus that they are near the ecliptic - comets may only be visible from one hemisphere (often plus some, but not all, of the other), even though naked-eye visible comets are typically further away than Venus.
You will not see this alignment if you are at the south pole or other points sufficiently south of the antarctic circle, either, given the time of year.
Lunar eclipses only last a few hours, so only the half of Earth facing the moon at the time can see them.
It also helps that the planets are roughly on a plane visible from everywhere on earth.
syzygy eclipses (one planet hides another) are also limited in viewpoints, tho
Oh Noooos, the world will end :)
I remember all the dooms day articles the last time, then I think all 8 aligned. That is what Voyagers used to get to the outer planets quickly and were they are now.
This time, I saw nothing about "world ending". I guess they moved on to other things. Too bad NASA was not funded enough to use this to launch a more advanced spacecraft :(
> Oh Noooos, the world will end :)
reads this from Southern Californa
Legit.
It isn’t as fun to speculate about fanciful and silly world ending mechanisms like planetary alignment, when we’re actually locking in a bunch of ecologically devastation by boring processes like… status quo bias and failures to coordinate.
It’d be cool as hell if we were destroyed by some grand universal conspiracy. Instead, we’re doomed by the same force that makes the office lunch group unable to gather consensus around anything other than cheese pizza.
There's also a lunar occultation of Mars (which is near opposition itself, making it relatively bright) happening in a few days, and then again in February, which should be visible from parts of the northern hemisphere: https://in-the-sky.org/news.php?id=20250114_16_100
Is there anything special to learn about occultations like this or are they just curiosities like alignments?
By precisely timing them you can measure/check various facts like distance, diameter and so on. In fact, if you time them precisely from different locations on earth you can determine the shape of the occulting body (e.g. an asteroid occulting a star). And on occasion you can get a 'grazing occultation', for example a star goes behind mountains on the moon resulting in it blinking on and off; observe from multiple latitudes and it's possible to recover the profile of the range.
Occultations can tell you about the atmosphere of the object in front. Depending on the rate at which the background object fades can tell you about atmospheric density, composition etc. If it disappears suddenly it indicates there may be no atmosphere.
This sounds quite interesting. I’m considering buying a telescope for this occasion (we moved out of the city and I’ve been thinking about it for a while, the sky is always so clear around very).
What would you recommend as entry level beginner telescope? Is it worth observing all this via a telescope?
A good pair of binoculars will be sufficient. You didn't need a ton of light gathering capability for casual planet viewing like this.
Telescopes are a bit of a rabbit hole. Many cheap mass market telescopes are also known as hobby killers. A 6" dobsonian (reflector) is a good starting point for deep space objects like nebulae and star clusters. For planetary viewing Schmidt-Cassegrain telescopes are great.
However, learning to use a telescope requires time and patience. Taking it to the field for an event like this for the first time may be frustrating as you will be spending most of the time figuring out how to collimate and align it.
I certainly don't mean to discourage you from getting one though.
A good pair of binoculars is much easier to use. They require no collimation out of the box and show an upright image that makes it much easier to navigate the sky, at the cost of reduced magnification and light gathering capability. You will be surprised how many celestial objects even 10x magnification reveals that are invisible to the naked eye.
Happy planet gazing!
My brother started at "I'll just buy one telescope" and last I checked has just finished constructing a powered observatory on some remote land where the telescope and rooftop motors can be operated entirely remotely through cell connectivity. This is a worse hobby for your wallet than having a boat.
Someone else did this, then built 20 more next to it. Now it's a business where they sell telescope time to researchers and hobbyists. I imagine it's profitable for them.
Binoculars are a bit misleading though as most people tire of trying to keep hold of them and track steadily. If you’re going to the level of getting some sort of mount/tripod for the binocs, you might as well step up to a telescope with GoTo features with tracking.
There are devices that allow you to connect your binoculars to standard camera tripods.
Where does one buy good telescopes nowadays?
For most of the last 50 years I would have said order from Orion Telescopes, but they abruptly disappeared last July.
High Point Scientific is a great option. They sell tons of options and have great service.
For example, this is an extremely commonly recommended for serious beginners that is sold by them: https://www.highpointscientific.com/apertura-ad8-8-inch-dobs...
No a telescope won't help. The 'linear' alignment spans the whole sky and is best seen with the naked eye.
You can click a pic with a wide-angle lens (whether on your phone or a camera).
Will a picture from a wide angle lens actually show the planets? I thought planets just show up as a bright dot in the sky.
> Will a picture from a wide angle lens actually show the planets?
Yes.
> I thought planets just show up as a bright dot in the sky.
Correct. :)
There's no real way to get around that geometry problem, you can either see several at once but they're pinpricks or one at a time but potentially somewhat more clearly.
To add to this, I'll try to give an idea of how much zoom (or focal length really) you'd need to get a picture with detail.
I took photos of both Jupiter and Saturn w/ a Canon R7 and the RF 100-500mm lens, with a 1.4x extender. The 1.4x extender make the lens act like 700mm instead of 500mm. The R7 being an APS-C sensor adds another 1.6x factor, making the combo the equivalent of 1120mm. In these photos the planets are still just dots. The camera takes 32.5 megapixel photos. When zoomed in to the pixel level, both planets were still tiny, about 50 pixels wide. It was enough to see Saturn had a ring and some color striping on Jupiter, but that's it.
The iPhone main camera is like 26mm (42x less zoom). The iPhone 13 Pro's telephoto lens is 77mm (14.5x less zoom), and the iPhone 15 Pro Max is 120mm (9.3x less zoom)... so you're unlikely to get much more than what looks like an out of focus few pixel wide dot even on the zoomiest of iPhones, but with that wider 26mm lens, you just might be able to capture them all in one shot.
To me, what's more technically impressive than the fact I took pictures of the planets with readily available camera gear was that I did with 1/125s shutter speed, handheld, standing in my yard. The accuracy of the image stabilization needed to pull that off is what astounded me the most.
Yes, but they will show exactly as you thought with the exception Mars will be a noticeable red dot. Uranus is usually too dim to see though. Usually to photograph Uranus and Pluto requires multiple nights worth of images to align and see which dot moves between the images. That moving dot is the planet
A $200 6 inch / 150mm reflector with the eyepiece on the side is a decent backyard starter scope. You can see the moons of Jupiter, Saturn's rings, the crescent shape of Venus, and nebulas. Ask your local library about the local astronomy club. Someone may have a >200mm scope.
I agree with the other recommendation to go with binoculars for your first foray into assisted sky viewing.
Another point in favor of binoculars for people living out of the city is that places out of the city often have more wildlife. Binoculars can be great for observing that.
When choosing binoculars there are a couple tradeoffs. Binoculars are listed as M x D, where M is the magnification and D is the diameter of the lenses in mm. For M here are some considerations:
• Bigger M makes things look bigger.
• Bigger M also reduces the field of view.
• The smaller the field of view the steadier you will need to be able to hold the binoculars to keep something in the field of view. A magnification of 15 for example would probably be useless for most people who are not using a tripod and trying to keep a flying bird in view. Actually it would probably even by hard with a tripod. But for looking at something that isn't moving (or whose apparent motion is very slow like a planet) 15 might work by hand and would be a piece of cake with a tripod.
For D some considerations are:
• The bigger the D the more light the lenses gather, letting you see dimmer objects.
• The bigger the D the more the binoculars weigh which makes it harder to keep them steady without a tripod and tires you out faster.
Another thing you might want to consider is the "close focus distance". Binoculars can focus on things from the close focus distance to infinity. For binoculars meant for astronomy the close focal distance can be 50 feet or more. Not a problem when you are looking at the Moon, but might be if you want to take a look at a squirrel frolicking in your yard.
Binoculars meant for wildlife will have a much shorts close focal distance. For example I've got Celestron's Nature DX 8x42 binoculars [1] and their close focus distance is 6.5 feet.
[1] https://www.amazon.com/Celestron-71332-Nature-Binocular-Gree...
Lots of celestial events in the US 2024/5! Eclipse, then aurora reaching down to southern New England, now this.
Are there more celestial events than usual, or did celestial events start trending after the two eclipses?
The week after the most recent US eclipse the media started reporting on every single celestial event, no matter how small. The eclipse got so much traction that it seems like they were trying to drag it out as long as possible.
Any given one of these events might be especially rare, but that's the birthday paradox in action: if you're looking for it you can find any number of rare celestial events in a year!
The Aurora by itself is usually a once in a lifetime thing. That being said, the sun is projected to do this kind of thing more often long term. So this may be the start of a new trend. Though the solar cycle is around 11 years long, so this is the last year for quite a while that it's statistically more probable.
It's been quite a show! Some nice CMEs, flares, comets and now a big alignment. I feel really blessed to be under clear skies to see these ancient celestial bodies dance across the night sky.
Does that align all gravity creating a massive solar flare?
The infographic: https://starwalk.space/gallery/images/planetary-alignment-in...
How rare is it?
That’s not really possible to exactly answer as it depends upon how tightly they are aligned. The last occurrence was March 10, 1982, and they aligned in a 95 degree arc. This degree of alignment will happen once every 175 years on average. However, an alignment within 4 degrees, for example, would occur every 400 billion years. In other words, never because the sun is expected to only last another 6 billion years.
Will this be visible in the Southern hemisphere?
Shouldn't there be some apocalyptic, end-of-the-world conspiracy theory to go along with this? I'm almost disappointed.
I'm sure that astrology-Instagram is full of all kinds of ideas about what this means.
Yes, this was in a documentary called MacGyver: Lost Treasure of Atlantis.
(this is a joke, because hn)
Fascinating article. Never heard of this. There's a (likely mentally ill) dude in Atlanta who puts up these conspiracy signs on the highways about the "annunaki". He put up some about "Shadow Zuck" and "Vampire Elon" over Christmas.
It is difficult for me to not just reflectively think of the spinny solar system model used in schools when the reality is an orbital plane that differs for each planet circling the gravity well drain plug of the sun and us all circling the drain of the black hole at the middle of the galaxy, itself hurling through space, and for all of this only to really mean anything in relation to other objects in specific contexts heh
PBS Spacetime has a good video on how Earth moves through the universe based on multiple reference frames for anyone interested.
Haha, 77 comments so far!
With this comment, I shall evilly spoil this particular 'alignment' ;-)
These were interesting when I was a kid, but there are so many specifically rare astronomical events that I'm left with a whole lot of "meh."
That’s sad for you. Anytime you can view something that only happens once every so many generations is interesting at the least. If it’s not your hobby, then just say so. That’s like me saying I think all of the GPT chatter is meh. It doesn’t diminish it for those that think it’s man’s greatest accomplishment.
One can definitely still be an avid astronomy hobbyist while finding syzygies seem to have lost their luster over time. It is a bit sad (in a way) but I'm not sure that implies it should be taboo to mention.
You don't want people excluded from the hobby on both ends - those that enjoy something particular should not be put down for enjoying it and those of the opposite opinion shouldn't be made to feel they must not be a real hobbyist as a result. Everyone should be able to talk about what they personally do and don't like about it while still enjoying the hobby overall.
I don't get why everyone keeps talking about the planets aligning. All the planets are pretty much in the same plane. So if you are on one of the planets, all of the others will always be in a line.
edit: to those downvoting me, can you explain why?
The special occasion is that their phase angles are all of a similar value so they are aligned next to each other. The phase angle describes the position in their respective orbit. If you imagine to look "down" upon the solar system, it would be the angle towards 12 o'clock.
It is rare because the further the planets are from the sun, the longer their orbit periods are. While Earth completes the circle in just a bit above 365 days, Neptune for example takes nearly 165 years to do a round trip. So it would take some time for the slower planets to meet again in the same region in the sky.
No, by being in a plane, the seven planets form a polygon.
If you are in a planet, there is a line to any other planet. Two planets form a line. Three planets form a triangle. Four planets form some irregular polygon of four sides. And so on.
In this case, the area of the polygon formed by the seven planets is minimal, for a period of several years, and they are effectively, almost in a line.
This is not a common occurrence.
I believe the person you're responding to was observing that the planets will appear to be in a line to an observer on the surface of one of those planets.
I think you're missing the part that from the surface of the Earth, we can never see that whole plane at once. So the special part here is that all the planets are simultaneously in one half of a partition of the plane by a line going through Earth.
At anyone time due to the different radius of their orbits, some planets might be positioned so they would be visible during the day (making them not actually visible). These “alignmnets” mean that they are visible at the same time in the night sky. Them all being on the same plane just means they are located in different spots on the same line in the sky
You are of course right. But for an observer on Earth, planets can be below the horizon. The difference this time is that their orbits are aligning in the other dimension as well, meaning they will be all above horizon when your observation point spins into place.
I didn’t, but I assume they downvoted you as a quick way of saying no to your question, which you chose to phrase in the form of a correct statement.
Oh no
