Starship Asterisk*

Lots of clouds; so far it is an overcast day!

Same here, Orin. It was supposed to snow here, but nothing so far. I hope that the clouds don't cover the moon during the lunar eclipse!

orin stepanek wrote:Lots of clouds; so far it is an overcast day!

An overcast day? Hah! Orin, I feel as we have had overcast sunsets for at least a month now. Probably two!





No wonder Venus has gone missing from our skies.






I agree with George Harrison: Little darling, it seems like years since it's been clear!

Ann

TNT wrote:Same here, Orin. It was supposed to snow here, but nothing so far. I hope that the clouds don't cover the moon during the lunar eclipse!

It wound up snowing most of yesterday and is still snowing! I put my truck in the drive while my wife is at work; hoping that the plow will come by so I can park back in the street. Must have dumped another 3 or 4 inches on us again! Thankfully there is no wind. And so I saw snowflakes in the sky last night!

The weatherman keeps saying that there's going to be snow here, but it doesn't snow. Come on! Get your predictions right, for once! I want snow! (but not during the eclipse or I'll be twice as mad. )

Ann, is that a sunset or an optical effect caused by cirrostratus clouds?

That picture is Venus, TNT! Venus is in its most "crescent" phase, and only a thin, thin sliver of it is lit by the Sun. In my opinion, what we are seeing is various layers of the Venusian atmosphere.

Ann

I did not see more than a small sliver of the lunar eclipse. It was too close to the horizon, and the trees blocked my view. Hopefully the next one will be far from the horizon and in the east.

Too hazy to see the eclipse this morning! Oh well; there will be pictures I'm sure!

Yesterday near sunset, I was walking northeast in downtown DC. I saw the moon in the east eclipsed by the flag atop the Old Executive Office Building. Oh, how I wished for a camera!

This morning, I saw the full moon in the western sky sinking into clouds that were progressively reddened by the earth's shadow, but could not see the moon when it, too, was shadowed.

I cycled to a church on a hill where I would have a good view of the horizon, and also I would be absolutely sure of the cardinal points of the sky, since the church is built in such a way that one end of its nave points due east and the other end points due west.

I wasn't just going to try to see the lunar eclipse, but I was trying to see Venus, too.

For December, the twilight sky was relatively clear. It was relatively clear, as I said. It may have been the clearest sky I have seen around here this side of October, which doesn't mean there were no clouds in the sky.

The sky was at its cloudiest in the east, where the eclipsed Moon would rise. The Moon would be totally eclipsed when it rose. Well, I saw nothing there but clouds.

So I started staring west instead, trying to see Venus. I started looking for Venus at about 3.45 p.m., and Venus would set around 4.35. The Sun had set at 3.32. December.

I saw nothing.

Correction. I saw Jupiter. It was already moderately high in the sky, and even though the sky was far from fully dark, Jupiter was bright and obvious. So why, then, couldn't I see Venus?

At regular intervals I went round the church to look east instead, to try to see the Moon. At about 4.10 or so, I saw it! The totality was over, but the clouds had parted, and a relatively thin "boat-shaped" crescent could be seen, as if the Moon was "smiling". The "lying-down crescent" wasn't as great as a reddened Moon would have been, but it was cool enough.

But still no Venus. I stared and stared. At 4.15, I gave up. It was really windy and cold.

I cycled to my best friend instead. Interestingly, she has a pretty good view of the western horizon herself. As I was almost at her house, I saw a light in the sky, really very low, so that it seemed to be "mixing and mingling" with the streetlights.

It was Venus. Goodness.

I was underwhelmed. Jupiter was already high and blazingly bright in the darkening sky. Venus was very very low and not strikingly bright at all in the fading twilight.

I still don't agree with Chris, who said it was impossible to miss Venus in the western sky after sunset. I had to make a very considerable effort to see it, and when I succeeded, Venus wasn't much to see.

I remember perhaps ten years ago, when a brilliant Venus was suddenly seen very low in the western sky. A lot of Swedes panicked, thinking they were seeing a UFO.

None of those who may have seen Venus around here tonight are going to call 911, that much is certain.

Ann

Ann, Venus is pretty bright! I saw it last night just after sunset when I was heading back southwest from where I'd been, and again tonight when I was done biking. (I usually take stock of the sky when I'm done riding; of course, I look at it while I bike, too!) Saw Jupiter last night and tonight, too, but didn't see the moon tonight until I was driving home from the trail; I kind of wish I'd biked at the lake a little longer, as it's lovely to watch the moon rise while biking around the lake. Most of my bike lights need new batteries, though, and it's dark in the woods after nightfall, so I couldn't really stay.

(All that said, Jupiter is just outstanding!)

Ann wrote:I still don't agree with Chris, who said it was impossible to miss Venus in the western sky after sunset. I had to make a very considerable effort to see it, and when I succeeded, Venus wasn't much to see.

It has to be something atmospheric- some sort of haze of thin clouds, or just the effect of looking through more (unclear) air. Under clear skies, Venus is currently brighter than Jupiter, from the moment it first becomes visible, until it sets (or at least, until it is within a few degrees of the horizon).

(That's what my star charting program says. But I just stepped outside to check, and Venus is distinctly brighter than Jupiter, even though it is still in twilight and Jupiter is against dark sky.)

Well, one possibility is that I didn't see Venus at all, but a star. I thought, as I came home, that I might have seen Arcturus instead of Venus. But Arcturus would set before Venus, and it would have set at the time when I saw what I took to be Venus in the sky. Also Arcturus would have been twinkling madly when it was so low.

The reason why I thought it might just possibly have been Arcturus instead of Venus, although they would be setting rather far apart, is that I'm not sure of what is exactly due west and due east and so on when I'm not at my home, where I know the cardinal points of the sky. Of course I could have tried to locate Polaris, but I didn't think about that. But in any case, the sky was far from really dark, and it wouldn't have been that easy to locate Polaris.

But my real problem is that even if I know the exact cardinal points in the sky, I'm not sure exactly where Venus is supposed to appear after sunset. Is it supposed to appear "exactly where the Sun has set", that is, where the twilight sky is at its brightest in the southwest? Or is it supposed to appear to the right of where the Sun has set, more due west? Or even to the left of where the Sun has set, more to the south? As I was standing on the hill with the church yesterday, I knew what part of the sky was due west, but I realized that I didn't know where Venus would appear.

I'm still not sure that I actually saw Venus yesterday, given how unimpressive it was. Yes, it was definitely very bright for a star, but it was really a lot fainter than Jupiter. Also, Jupiter and Venus - if it was Venus - were not at opposite parts of the sky. They were not at the horizon at the same time at all, and instead of being 180 degrees apart, they were more like, say, 120 degrees apart.

So I keep being stumped and wondering about Venus.

Ann

One way to tell due West is to look for the sun prior to sunset. As it is almost the winter solstice, the sun is setting about 23deg south of west. So due west would be just over 2 fists at arms length toward the north

Thanks, BMAONE23, I appreciate it! Although I suspect that the Suns sets considerably farther to the southwest here in southern Sweden. After all, the Sun is above the horizon for only seven hours out of twenty-four this time of year!

I so wish I knew exactly where in the sky Venus actually appears. Is it "just above" the spot where the Sun has set, or to the right of it, or to the left of it?

Can't resist showing you this picture of the lunar eclipse on December 21 (solstice day), 2010. The tall building in the picture is Malmö's highest building by far, Turning Torso.



Look how much snow we had last December! Just take a look at the cars! So far, thank goodness, we haven't had any snow at all.









Ann

Ann wrote:But my real problem is that even if I know the exact cardinal points in the sky, I'm not sure exactly where Venus is supposed to appear after sunset. Is it supposed to appear "exactly where the Sun has set", that is, where the twilight sky is at its brightest in the southwest? Or is it supposed to appear to the right of where the Sun has set, more due west? Or even to the left of where the Sun has set, more to the south? As I was standing on the hill with the church yesterday, I knew what part of the sky was due west, but I realized that I didn't know where Venus would appear.

Here's a pair of images I shot on the evening of 7 December. Both were made with identical settings (1/4 sec, ISO 100, 28mm FL, f/5.6). This is actually a pretty fair visual match to the appearance of both Venus (left) and Jupiter in the sky right now. I shot these at 5:11 pm local (Mountain Standard, UT-7) time. Click on the image to get the full size, otherwise you might miss the planets, especially Jupiter.

The Sun, Moon, and planets approximately follow the ecliptic- but the position of the ecliptic changes over the course of the day. At solar noon, it is symmetric- just touching the (exactly on the solstices) east and west horizons, and dropping toward the south in the middle. Of course, the farther north you are, the farther south the Sun is at noon. At dawn right now, the Sun rises in the southeast (because the ecliptic intersects the southeast and northwest horizons at that time), and sets in the southwest (because the ecliptic intersects the southwest and northeast horizons at that time). This shifting of the ecliptic is why the planets are always best viewed in the winter (no matter where you are on the Earth)- in winter, the ecliptic is high in the sky at night.

When we are at full Moon, note where the Moon is rising and where the Sun is setting (which will be at about the same time). This will define the horizon points for the ecliptic. Then sweep out a big arc towards the south from these points. All the planets will lie approximately along this line. Currently in Malmö, when the Sun sets, Venus will be higher in the sky (about 18° altitude, almost two hand widths with the arms outstretched), and well to the south (nearly 25°) of the sunset point. For reference, Jupiter will be about 30° altitude at that time.

Venus is rapidly rising higher each night, so it is getting easier to see, and is visible longer after sunset. In Malmö right now, Venus sets two hours after the Sun.

Ann wrote:I so wish I knew exactly where in the sky Venus actually appears. Is it "just above" the spot where the Sun has set, or to the right of it, or to the left of it?

Imagine the track of the Sun through your sky towards sunset. It's a line stretching up to the left (towards the south) of where sunset occurs. A little back on that track -- that's a little up and more to the left of where the Sun just set -- you'll find Venus. This time of year it's almost exactly south-west from your location. Be aware that it's so close to the horizon that a hill or trees can block it from view, but as Chris says, it's getting easier each day.

Do you have any astronomy software? You can find inexpensive software which can tell you exactly where to look, usually doing so in a picture of the sky format. That's how I can be so specific about exactly where you can look. I just made a new location for Malmo, then told the software to "Go there" and bumped the time up to sunset. I use Equinox Pro, but there's lots of others that work fine.

Rob

rstevenson wrote:Do you have any astronomy software? You can find inexpensive software which can tell you exactly where to look, usually doing so in a picture of the sky format.

You don't even need to install any software. There are good star charts available on that display in your browser. Sky View Cafe is a nice one. Just put in your location (Malmö isn't in the predefined list, but for most purposes, Copenhagen is a suitable alternative) and pick your time. You can enable display of the ecliptic and see how it changes with the time. And of course, you can see what stars, constellations, and planets are visible, and where in the sky they are (or were, or will be).

At sunset, Venus appears to be above and to the left of the setting sun. Or, at a tertiary cardinal point, SSW (slightly more south than southwest).

Thanks a lot, everyone. It helps a lot to know that Venus is going to be to the left of where the Sun has set. It's a complete mystery why I couldn't see Venus to the left of where the Sun had set last Saturday, then. I had a fairly good view of that part of the sky. Yes, there were some trees in the way, but they had lost their leaves, and since I kept walking around, to make sure that no bright light was hidden behind the trunks or the branches, it just doesn't make sense to me that I couldn't see anything in that part of the sky if Venus was really there. Jupiter was the brightest light by far that I could see in the sky that night, until the Moon became less eclipsed.

I have no software installed that helps me locate the planets. My fascination with the universe has never primarily been about the planets. It has always been about the stars rather than the planets, and about the galaxies and the universe itself. I don't mean to say that I'm completely uninterested in the planets, but they are not the reason for the interest that I take in space.

I no longer buy books about astronomy, since they get dated so unbelievably fast in these days of the Internet. But I once took stock of how many books I owned on astronomy, and I found that I had more than seventy. Of those, more than half were about "general astronomy" - planets, stars, galaxies, the overall universe - you know, the works. Some were specifically about galaxies, such as "The Milky Way as a Galaxy", "The Galaxies of the Local Group" and "The Color Atlas of Galaxies" - that's one of my hands-down favorites. A few were specifically about constellations and stars, such as the magnificent "Atlas der Sternbilder" and James Kaler's fascinating "Extreme Stars". I own a fascinating book about Kepler and a richly-illustrated thin book about Einstein. One book deals with the Earth as an unusual planet, namely "Rare Earth".

But can you guess how many books I own that deal exclusively with the Moon? None. How many books do I have about Mars? None. How many books do I have that deal exclusively with our solar system? None. Don't I have a single book that concentrates on talking about planets? Yes, one: "Planet Quest" by Ken Croswell.

So you see, taking the trouble to install software that helps me locate planets is not one of my priorities. But I thank you all very much for your help!

Ann

Well, you could use one of the online tools, as mentioned... no downloading necessary. Chris pointed you to one. Google would point you to others.

With an Android, iPhone ,or similar devices, you can download an app called Google Sky Map. It gives the location of stars, constellations, planets, and Messier objects. For example, if you want to find Venus, you can hold the device and follow the ecliptic and point out where it is.

TNT, I think Ann is already on record as not owning a smart device. She could just click on the link Chris supplied, however, since that would show her where to look; no download needed.

Ann, I don't think you should feel too bad about not being able to see Venus. It has so far eluded me too . . and I have looked and looked, night after night, when the sky has been clear enough. I have used the Stellarium program to check where it should be and I can see what the problem is, at least from my location. I have hills to the south and west of my position and they effectively block any possible view of Venus because it is so low in the south-western sky by the time the twilight has darkened enough for it to be visible. It is dark here by around 4:30, but even if from my viewpoint the south-western horizon was much less hilly, Venus will already have most likely set. So, despite everyone else getting a great view from their more southerly latitudes, I think it is just not possible from here. You are on a more northerly latitude than I, Ann, so Venus will be relatively lower from your location too. I think it is likely that by the time the sun has been set long enough and the sky has darkened enough for Venus to be visible, it has also gone below the horizon from your viewpoint, or at the very least it will have sunk into the haze of the atmosphere and it's brightness diminished too much.