Oh me, oh my, oh Mars!

Mars gave me a real thrill this morning, which got me to thinking – if a friend were with me, he or she would probably have been totally unimpressed.

That’s one of the problems with astronomy – photographs of the astronomical world (such as those of Mars shown above taken from a Google search) are both familiar and spectacular these days and this raises expectations tremendously. I, on the other hand, have looked at Mars through a small telescope many times over the years – and ignored it studiously many other times – because I have been singularly unimpressed. Put bluntly, it usually isn’t a spectacular object in a small telescope – and even in a large amateur telescope – or for that matter professional one – it isn’t very exciting most of the time. For exmaple, here's a good simulation of what I saw this morning. This is taken from STarry Nights astronomy software. The white dots are stars that just happen to be in the same line of sight, but aren't really near Mars.

Can you have a good Mars experience through a small, Earth-bound telescope? Yes! Absolutely. But what you need for Mars to be really good are five things:

1. It must be observed during the six-month stint when Mars is relatively close to the Earth and this comes every two years – so that narrows the opportunity to one fourth the time. (Such a period goes from July through December of this year - 2005.)

2. You must use a good telescope in which the optics are well collimated and it should be of reasonable size. Large can be better, but small refractors with excellent optics can do fine. (My 8-inch Schmidt-Cassegrain will do fine, as well as the 15-inch Obsession reflector.)

3. It helps significantly if you are both a patient and experienced observer. (I’m patient, but relatively inexperienced, especially in regard to planets. But I’m learning!)

4. it will be best if you have rare – very rare - steady skies. This is what astronomers call “good seeing” and if it is to arrive at all, it is more likely after midnight than before. I have had good seeing, but never good seeing when Mars was available. However, night of average seeing can still be fullfilling.

5. Low expectations – even the best professional telescope on Earth don’t give you very good views of Mars because the limiting factor is Earth’s ever-changing atmosphere. Photos from space – especially robotic explorers – however are spectacular. And frankly, photos taken from Earth by amateurs through even small telescopes, are also quite spectacular. Don’t expect to see what the photos reveal. That said, in my book nothing equals a view of the real thing in real time with your very personal and quite spectacular eyes and brain.

Other factors help. Two years ago Mars was closer to Earth than it ever gets, but for folks in the Northern tier of states it was quite low in the southern sky and this made for poor observing conditions generally. This time around it is significantly higher.

So what did I see this morning? Not much by the standards of a veteran Mars observer – but I’m not a veteran, so it was much to me. I saw a tiny globe that obviously had a white cap (ice) and obviously had large, splotchy green and orange markings. What’s more, when I checked my mental sketch of the darker – green – splotches they matched up pretty well with the Sky and Telescope map of the section of Mars facing us at the time of my observation. (Go to this Web site - (a href="http://skyandtelescope.com/observing/objects/planets/article_997_1.asp">http://skyandtelescope.com/observing/objects/planets/article_997_1.asp - and click on “Mars Profiler” in the second paragraph. That takes you to a neat simulator which opens in a new window.)

Did I see any details this morning? No. But as I search my memory of past visions of Mars, this was the best. And it was simply exciting – hard-to-describe exciting – to know you were watching this fabled little globe up close and personal and it was revealing any of its secrets at all. What’s more, in this morning’s view was the promise of much better things to come – with any luck. Why?

First, right now Mars is less than 12 seconds in diameter and that makes a mighty small target when seen through a telescope.

But, by the end of October Mars will be much closer to Earth. This means it’s disc will be 20 seconds in diameter, a significant improvement. To give you an idea, here’s how it could look in my telescope on the evening of October 29. (That’s one of its two small moons, Diemos, next to it.)

Not huge, I agree, but still much improved. Take a look at this side-by-side comparison.
The point is, by late October, with any luck, I will be a more experienced Mars observer, since there will be many opportunities to develop my skills in the coming weeks – AND I will have much more to work with since Mars will be closer AND, if I’m really lucky I’ll get one of those magical nights of steady skies that are rare, but do happen.

These last two factors – observing experience and steady skies may be hard for the newcomer to amateur astronomy to grasp, but the bottom line is that steady skies means the level of detail you can see goes up significantly. What most people don’t understand is that our view through the Earth’s atmosphere of other planets is constantly shifting – and I mean constantly. I’m not talking about a change over days, hours, or even minutes and seconds, but changes within a second. To get a feel for how this makes objects look, take a look at this wonderful little movie simulating typical “seeing” conditions. It will drive you a tad crazy if you stare at long, but take a peek here:

http://reductionism.net.seanic.net/brucelgary/AstroPhotos/seeing.htm

In real life the changes are smoother than this “movie” but just as rapid.

The point is, even when seeing is marginal you do get occasional glimpses of details and you have to be prepared for them, Things change so quickly you tend not to believe your eyes. And it stands to reason that experience looking for such changing details does pay off.

So – for me my glimpse this morning was thrilling. I saw Mars through the 15-inch Obsession better than I have ever seen it before in my life. It looked real because it was real and it made me appreciate all the more the wonderful images being sent back by our robot explorers. But the bottom line is no picture can substitute for experiencing the real thing.

So if someone invites you to look at Mars through their telescope this fall – do it. But first, lower your expectations – then try to fully grasp that you are dealing with reality here – another whole planet worth of reality.