History is made at night
Character is what you are in the dark
Making the effort
This is something to which any amateur astronomer can relate. Often times just getting out there and doing it, even if the odds of success are low, is the key to a meaningful reward. Allegory for life much?
This short article has actually helped me make some decisions about my equipment that I was having a hard time making.
Clouds? What-evs.
Making the Effort
Bill Pellerin
Houston Astronomical Society
GuideStar Editor
www.astronomyhouston.org
The weather looks uncertain today. It was nice yesterday, but other obligations kept me from getting out under the stars. So, the dilemma – go to my observing site and hope the sky is clear tonight, or continue to work on this article for the Astronomical League web site?
Now that it’s daylight saving time (the bane of astronomers) it’ll be a few hours before sunset, and another hour before it gets really dark. We’ve all been in this position, right? Having to decide whether to make the effort to observe today or wait for a more certain set of circumstances. There’s the risk that you’ll miss a good observing opportunity and there’s the risk that you’ll prepare for an observing night that doesn’t happen.
I consider amateur astronomy an effortful endeavor. That is, to be successful you have to be willing to make an effort to get out and observe even if the probability of success is uncertain. Nothing ventured, nothing gained, as they say. What drives that willingness to make the effort to get out and observe? I believe that it is our passion for the subject – our desire to know more about the sky and the universe and how it works. I see this passion in my amateur astronomer friends and in the professional astronomers that I’ve had the opportunity to meet.
Since our club’s observing site is about 80 miles from home, getting the car loaded and driving that distance can easily be a two-hour proposition. When you get there, you still have to unload and set up for your observing session.
Is it possible to balance the effort and the reward? Yes, I believe that it is. On a beautiful clear day with no forecast for clouds (and a dark blue Clear Sky Chart), the risk that your session will be ruined by clouds and haze is low, and the reward (especially on a near new moon night) is very high. On a day where there is a good chance of clouds and the moon is in the sky the probability of a pristine observing session is lower and the potential reward from your effort is lower.
What can you do to improve your chances of success? Having a plan B, or even a plan C can help balance the reward to effort ratio. You want this to be a high number. A great night, with no clouds, is a high reward, so keeping the reward to effort ratio high is easy. Even if you expend a lot of effort you’d probably consider the reward to effort ratio to be 1 or higher.
Suppose that there is another site, your back yard, a nearby park, where you can go and do some observing with a simple to carry and simple to set up telescope. What kind of observing could you do from here? Bright stars, double stars, carbon stars, brighter variable stars, the Moon, planets, satellites and more. The Houston Astronomical Society, my home club, has set up ‘Urban Observing’ nights at a park not very far from my home. One purpose of these events is to provide observing opportunities for novice observers with more experienced observers attending to help the novices. Everybody gets to observe on a night, perhaps during the week, when you might not otherwise get out. Good reward for modest effort also provides a greater-than-one reward to effort ratio.
Other observing opportunities exist. How about a public outreach event? Last weekend, for example, a group of us set up telescopes at the Houston Arboretum (perhaps 5 miles from downtown) for an Arboretum fund raiser. The visitors were amazed by the views of the 2 day old moon, the moons of Jupiter, and Mars. They were delighted by Sirius (“the brightest star in the sky”), Betelgeuse, and Rigel. Even the Orion nebula was visible.
Plan C may involve doing some work with binoculars. Think you can’t see anything in a large city with binoculars? Wrong. I live three miles from downtown, and the skies in town are pretty bad, but I have observed comets from my driveway and plenty of double stars, planets, asteroids, lunar eclipses, and other things.
Getting out with a nice pair of binoculars is very satisfying (a good book is Binocular Highlights by Gary Seronik, available from Sky Publishing). I also suggest that you go out and identify bright stars in the sky. How many of the alignment stars that your computerized telescope uses can you easily identify in the night sky? The reward is sufficient for a low-effort endeavor so, again, your effort is in line with your result.
Can you pick out the star Zosma from the spring sky? Me neither; I have to look on my star map to identify it, but it’s one of my telescope mount’s alignment stars. Wouldn’t it be a good thing if I knew these stars without looking them up? (Zosma, it turns out, is in Leo and it is the northernmost star in the triangle of stars that define the tail of the lion.) Identifying these stars can be an unaided eye exercise. New knowledge of the sky for a limited effort.
So, in the end, it’s all about making an effort (small or large) to get out and do something. Not every outing under the stars needs to be a major all-day or all-night event. Even a half hour observing some bright objects can be fun. If you are at a loss for what to do, check out the Observing Clubs list on the Astronomical League web site. Many of these clubs are designed for bright sky observing.
Dark nebulae
While the title of this post would make a fine name for my next punk band, I’ll skip past any personal interest in the term and make this post about astronomy stuff, as always.
The term “Nebula” was first used (so far as I can tell) by William Herschel in the first half of the 18th century to describe the fuzzy stuff in the night sky, as opposed to the single points of light we see from stars and planets. Some of these things are whole galaxies, like M31, which was (and sometimes is still) called “The Andromeda Nebula” and M83, which is the name of a band, the Southern Pinwheel galaxy. The “M#” designation refers to the Messier catalog, which is a list of astronomical items with nebulosity, btw. The others are BIG clouds of gas and dust within our own galaxy. The term seems to stem from the Greek words for “cloud or fog”, nephele or nephos, which seems sensible.
Of course, the reason we see these at all is primarily because of the stars within these pockets of gas and dust, some of which are forming stars and planets , even as I write this. Our sun and planet were born in a nebula, long ago, from the scattered remains of a big star that met a violent end. But what if there aren’t any (or enough) stars around to light everything up? If we’re talking about visible light, this would mean it remains dark. If you’ve ever wondered why you can’t easily see the center of our own galaxy, it’s because there’s so much of this stuff in the way. You have to leave the visible spectrum of light and delve into the longer wavelengths of infra-red to see through it.
Here’s a picture of LDN 1622 that illustrates this very well.
Hey LDN 1622, you make a better door than a window.
Even with better known nebulae, like the famous one in Orion, the stuff you see is only part of the picture, they have expanses beyond what’s normally illuminated that block the light of other stars. Or, even the center of a galaxy that’s less than 30K light years away when they team up.
Shooting it with lasers seems like the answer.
So, if it weren’t for these things, we’d see many more stars than we do now. Of course, it was stars that made them (the parts that aren’t just hydrogen anyway) and if it weren’t for nebulae like them our sun wouldn’t be here, so neither would we. Seems like a fair deal to me.
Three degrees of separation
While this winter has been a total let-down as far as any kind of abundance of clear skies has been concerned, there is some good naked-eye planet observing to be had right now. Fortunately, looking at unmagnified bright planets doesn’t require especially ideal conditions, or even much knowledge of the night sky. You look at the bright stuff, even from within the limits of a large city, and see something special. It’s pretty cool.
The thing that is standing out right now is Venus and Jupiter only about three degrees apart in the night sky, from our perspective anyway. As far as bight planets go, Jupiter is second only to Venus and they’re the second and third brightest objects in the night sky, so this is pretty obvious.
Alan Dyer of (amazingsky.net) took a great photo of this last night.
Venus and Jupiter are the bright ones in the middle.
Additionally, both Mars and Mercury are visible, though Mercury is going to be gone pretty soon. A few days ago, Mars was at Perigee with Earth (Perigee = as close as it gets) and is easily visible as a conspicuously red dot. In New England, Mercury only gets about five degrees above the horizon and we have a lot of trees and hills, so spotting it can require a good vantage point. Don’t feel too bad if you miss it this time around, it’ll be back in a few months. Mercury is pretty weird and its year is only about 88 Earth days long, while its day (the time it takes to make a full rotation on its axis) is about TWICE that. So, one Mercury day takes two Mercury years. Like I said, weird.
Look at this weirdo.
I always imagine Jack Horkheimer smiling that Jack Horkheimer smile when I talk about naked-eye observing, but there’s something truly excellent about seeing a point of light in the sky and knowing what it is. Even if you don’t know what they are, yet, you should “keep looking up” anyway. Maybe you’ll see something that will make you want to learn more.
Farewell, Valley of Death
As bad as I’ve been about keeping this blog blogging, last week I had the finest excuse possible: I was in Death Valley with close to no internet access. This was mostly intentional. While I won’t post my amazing (to me and my wife only) vacation pics on here, there was some astronomy stuff that happened.
First ad foremost, I was able to view totally dark, clear skies and see the milky way clearly. It’s hard to find skies that dark around here and it had been a long time since I’d enjoyed them. It was wonderful. Since the moon was 3/4-ish full, it happened pretty early too and then we were able to watch the moon rise over the mountains. It totally kicked ass. Then, the following morning, we were greeted with this:
This is all the astrophotography you're getting from me today.
The other big highlight was Venus and Uranus being right on top of each other, which made Uranus an easy target. I was actually able to see that little blue bugger with binoculars, which was wild, even with Venus shining brightly nearby. Obviously Uranus isn’t little and Venus isn’t anywhere near it, but you know what I mean.
A good week for pictures
You’ve probably seen the amazing mosaic of Earth that was just released this week, taken by NASA’s Suomi NPP satellite, but in case you missed it, here it is again.
It’s hard not to see an image like this and not grab people and scream Carl Sagan quotes in their face.
The image you might have missed, unless you read the Bad Astronomy blog, is this amazing one of Mars, which is a composite of images by the ESA’s Rosetta spacecraft, constructed by Emily Lakdawalla.
Pretty cool stuff! Even cooler is that taking these pictures wasn’t part of either mission, but there they are.
Cracked me up.
I’ll get back to the rest of the Voyager posts eventually, but in the mean time, I read this funny thing on cracked.com that is relevant to this blog.
6 Myths Everyone Believes About Space
There may be some errors here and there, but the main points are correct. It’s meant to be funny, so take it as that.
Even as a kid, I knew there was something amiss about the idea of this guy.
Phobos-Grunt
Phobos-Grunt is in the news a lot right now and if you’re into this kind of thing, you probably already know the story. It was supposed to visit a small moon of Mars (Phobos) and bring back some of its dirt (“grunt” is Russian for “dirt”), so we could get some better idea of how these odd satellites formed. It launched successfully, but then was stuck in Earth orbit when a thruster failed to fire. Despite some suggestion that it was interfered with via land-based anti-satellite technology (I’m looking at you Canada), the failure was most likely some mechanical issue that crept up while waiting for the typically short launch window for Mars.
Re-entry will eventually make it look more like novelty dog poop though.
Now, it’s about to re-enter Earth’s atmosphere and some of it will almost certainly make it to the ground. There’s a one in a few thousand chance of it hitting a populated area, most of Earth not being populated. That won’t stop your local news from making seem like it’s probably going to land on your child’s school during nap time. When the German ROSAT satellite was about to come down last year, I heard a newscaster say “your odds of YOU getting hit by this space junk are better than hitting the lottery”, which was simultaneously completely wrong and intentionally misleading. There were so many zeroes actually associated with those odds, just as they are with Phobos-Grunt, ignoring them completely was and is the only sensible thing to do.
You can track Phobos-Grunt, while it’s still intact, here. Current predictions say it’ll be down by tomorrow, but it won’t take much for that to change.
Voyager I and II (Part IV)
After visiting Jupiter in 1979, the next destination for the Voyager mission was Saturn. Saturn isn’t a difficult target for a modest telescope on earth, visually or otherwise, and a nice telescope can even work out details in the rings and sometimes its largest satellite Titan, despite it all being about 750 million miles away.
So, in the fall of 1980, Voyager 1 finally arrived and began sending back images and data that forever changed the way we think of Saturn, its rings and satellites.Voyager 2 would be right behind it, arriving in the summer of 1981.
That's more like it!
When Voyager 1 sent back the first images of the rings, astronomers began to theorize about how the now visible structures of the rings might occur and be maintained, some of which were quite unusual. Some thought the smaller gaps were being cleared out by larger objects orbiting within the rings, but the better cameras on Voyager 2 showed nothing of the sort. We now know that there are moonlets and shepherd satellites within the rings, but even with the fine images from Voyager 2, the rings are still extremely huge and these were not visible, but they’re not the whole story anyway. The simple way to explain it is to simply say that the rings are held in place with a gravitational dance between Saturn and the moons that orbit it. It’s a complex structure, but very elegantly maintained.
This references the Cassini mission, but it gives some idea of how interesting the Saturn system really is.
Of all the satellites orbiting Saturn, none is more unusual than Titan. It’s bigger than Mercury, has an atmosphere thicker than Earth’s and if it weren’t orbiting a larger planetary body, we’d consider it a planet on its own. Observations in the beginning of the 20th century revealed Titan’s atmosphere, but it wasn’t until the early 70s that Carl Sagan suggested that Titan’s thick methane smog might be producing complex organic molecules, which would rain down and collect in pools. Since the atmosphere is almost totally opaque at virtually all wavelengths of light, we didn’t get confirmation on the hydrocarbon pools until recently, but Voyager did confirm the nature of the atmosphere itself.
Come for the ethane lakes, stay for the atmosphere.
Voyager revealed a tremendous amount about Saturn’s composition, dynamics and the way the rings and satellites interact, plus a few additional satellites we hadn’t seen before. It did exactly what it set out to do and laid the groundwork for future missions like Cassini and the eventual landing of the Huygens probe on the surface of Titan.
To keep it all in perspective, that large gap, called the Cassini Division, is about the size of Earth's radius.
It’s terribly fascinating stuff, but from here on out, further planetary explorations would be done by Voyager 2 alone. Voyager 1 took a hard left after Saturn and begun its journey into the great unknown, which it still hasn’t quite reached even after three decades.
The next stop for Voyager 2 is Uranus, which funny name aside, has some truly crazy stuff going on.
Voyager I and II (Part III)
In the first of these posts, I mentioned that the Voyager program was initially going to be part of the Mariner program, which visited Mars in the late 60s and early 70s. The original plan was to take a grand tour of the outer planets, but as is always the case, the budgets got in the way, the mission was changed a bit and ultimately re-named. It’s amazing to think that a program so extremely successful was one that had its funding pinched. A similar example is when you see those beautiful photos of Saturn from Cassini, remember that budgetary concerns caused them to cut the articulation system for the camera, so the entire spacecraft has to turn in a special direction for whatever shot it wants to take. Say what you want about NASA, they have a history of getting things done despite a seemingly constant budget battle.
On a happier note, one big help to the Voyager mission was a newly (at the time) devised way to save propellant by using the gravity of the planets it visited as a boost. We now think of this as commonplace for our spacecraft and frequently see referenced in the world of sci-fi as a “gravity slingshot”. Another bonus was a very convenient alignment of the planets the mission intended to visit. Despite all of expected and unexpected challenges, the Voyager program had a lot going for it right from the get-go.
This picture links to a more thorough explanation.
Voyager 1, oddly enough, launched second and doesn’t get as much attention nowadays as Voyager 2, which went on to be the only craft to ever visit Uranus and Neptune. Because it began its journey into interstellar space just after visiting Saturn, however, Voyager 1 is now MUCH further from our sun, over 10 billion miles, which is about three times the distance to Pluto! Wild.
Both craft gave the world the fist good images of Jupiter in 1979 and even then, not two years after launch, already secured the success of the mission, in my opinion. Of course, I was only four years old when all this was happening, so my opinion didn’t count for much at the time. Since then though, I’ve lived my life in a world where we know what the outer planets look like. It’s hard for me to imagine a world where we don’t all know what our own solar system looks like in detail, but prior to Voyager it was merely fuzzy, blurry images with only a little bit of detail. Then, doing just what it was sent to do, Voyager 1 sends back this:
Whoa.
The visit to Jupiter showed us how dynamic the seething and churning gas giant really was: a complex system of storms and extreme forces. These images became the standard against any future image would be measured and in some cases, still are. One of the most astounding things to keep in mind, is that Voyager I didn’t just have some snazzy digital camera on the end of a robotic arm that could happily snap off photo after photo, they had what were essentially two TV cameras (one wide angle, one not) that were taking in data to be turned into images back on earth.
Think for a moment about the split second it takes for an image to be downloaded to your computer via whatever current internet connection you have. Then remember what this was like when you only had dial-up, maybe not even 15 years ago. What a joke! 56kbps was “fast”? LOL!
So, now you’re done laughing about how you once may have had to wait minutes for a wired connection to produce an image of a kitten dangling from a branch, praying nobody tried to call you before the file was completely downloaded and you could read the “Hang In There!” at the bottom. Now, imagine it’s almost 20 years earlier and instead of a telephone wire, you have a radio interface with a download rate of 160bps (note the lack of anything before the “b”) and instead of the signal coming from a website for motivational cat pictures, it’s coming from a spacecraft 500 million miles away, traveling at high speed and any transmission takes over four minutes to reach you. Good thing your computer has a fresh 256K roll of magnetic tape!
Now look at the above image again and it’s easy to understand why this was so damn amazing.
The other big surprise, which I briefly mentioned in the first post, were several discoveries about Jupiter’s moons, most notably Io and Europa. Io, it turns out, is like a giant paperclip being bent back and forth by Jupiter and the other moons’ gravity, heating it up and making it the most geologically active body in our solar system. It spews sulfurous magma up into plumes that were first noticed by Linda Morabito, making her humanity’s first witness to volcanism outside Earth.
Io is very beautiful, extremely volcanic and almost certainly smells terrible.
Europa, on the other hand, is an icy wonderland. Giant fissures and chaotic surface features make it seem certain that a huge ocean lies beneath the surface, perhaps completely separating the ice shell from the rocky surface of the moon. The ubiquity of the liquid water is not in question, but the thickness of the ice is. We’ll know soon enough, we should have a probe there in less than a decade that will finally answer this question and many more. Before Voyager though, we had little more than speculation about what Europa was like. After Voyager, it became common to think of Europa as a possible haven for life outside earth. If something is living in the solar system beyond Earth, and you asked me to bet on where it is, I’d put my money on Europa.
This is a mosaic, not a single image, but it is beautiful. I'm not saying I'd like to live there, but I hope something does.
So this was the first stop, just the beginning. It made the wait for the Voyager mission to reach Saturn even more exciting and gave us plenty of science to keep us busy until then. Certainly they did more than take these few pictures of only these moons and the great red spot, so I hope you find out the rest of the story from the Jupiter system visit.
One more thing, however, that I feel is germane to this post and I feel compelled to mention; last year Björn Jónssen over at unmannedspaceflight.com used voyager data from 1979 and modern imaging methods to create a mosaic of the great red spot that is utterly mind-blowing. The image below will link to the enormous original, which should absolutely be seen by everyone.
Again, whoa.
Next stop: Saturn!
Voyager I and II (Part II)
In the years preceeding Voyager, we had a few spacecraft that carried the name Pioneer, most notably Pioneer 10 and 11, which in 1973 and 1974, were launched to be the first Jupiter and Saturn explorers. In fact, Pioneer 10 was the first spacecraft to go beyond the asteroid belt, it’s sister ship right behind it. They didn’t have any fancy-pants imaging capabilities, but they took a lot of measurements, sent back a lot of data and, in no uncertain terms, paved the way for the success of the Voyager missions. They also carried a message to any alien civilization that might eventually find them, maybe hundreds of millions of years from now, as they float through the unimaginable emptiness of interstellar space. It’s in the form of a gold plaque, designed by Carl Sagan and Frank Drake, drawn by Sagan’s wife at the time, Linda Salzman Sagan. How flippin’ cool is that?
The man and woman on the plaque were deliberately drawn NOT holding hands, since Sagan was worried an extra terrestrial might think we had two heads.
Pioneer 10 sent it’s last transmission in 2003, 30 years after launch, and continues to travel away from our solar system with its sister Pioneer 11 doing the same in almost the opposite direction, now only silent emissaries of the human race.
When it came time to think about adding something like this to Voyager, it was definitely taken to the next level. Both Voyagers have, beneath a golden cover with usage instructions engraved upon it, a gold record that contains a fantastically rich greeting from earth, plus pictures, music and information on the things that make us, and our planet, tick. NASA has a nice flash site that allows you to experience all the information that it contains. You’ll probably be shocked by how much there is. It makes the Pioneer message seem like a hasty doodle.
Everything an alien needs to listen to the greatest hits of Voyager I and II, which went gold on the first day. This also includes the pulsar-based map to earth.
If you saw the movie Starman, you’ve heard a little bit of this record already.
If you saw Star Trek: The Motion Picture, you may think the consequences of sending spacecraft like this out into space will be extremely silly.
I think it was a very big deal that we did this. We added time, energy, cost and weight to an expensive and complex NASA mission, with no hope of any receipt of the message in our lifetimes. It’s a note in a bottle, tossed into an ocean far, far more vast than any we could possibly imagine. Not to mention that we don’t even know if there’s anyone out there, on any shore, to ever read it, should it ever find its way to one. It’s the longest shot, a leap of faith, the willingness to act with guidance only from our hopes and imagination, the things that make us who we are. The things that make us human. Even if it’s found by some intelligence so different that they never decipher any of the words or meaning, they’ll know it was sent by someone, somewhere, and then the most important part of the message will have been received. It should seem to any of us to make perfect sense that we did this.
Then again, who knows, maybe we’ll get a visit from a young Jeff Bridges and he’ll reveal the villainy of our government, which would seem pretty easy these days.
Certainly these messages weren’t the reason we sent these craft out there in the first place, it was simply one extra thing that made them even more amazing than they already were as tools of science. The next part will be about some of that science and how it changed our view of where we live in the Milky Way.
History is made at night 