It seems that a couple of posts I’ve made in the past week dealing with political topics have really brought out the worst in some commenters. I deleted many comments or marked them as spam because they used bad language, were insulting, or were obvious trolls.

So I will repost my policy on comments. Maybe I should do this every week, since obviously as election time rolls around I’ll have to deal with people who simply cannot express themselves politely.

The commenting policy is posted below. Learn it. Love it. Listen to it, or you’ll be wasting your time commenting here.

I didn’t want to do this, I really didn’t, but my hand is forced.

For some reason, this past week, I have had to edit a comment every day because someone has used "bad" words in it. I like this blog to remain, if not kid-friendly, then young-adult friendly. That means getting it into schools and such, and that means I have to be a nanny.

So here is my policy for commenting here. It is neither complete nor unchangeable. But this will do for now.

1) Be polite.

That’s it. That’s my rule.

That should be easy, right? Don’t go attacking other people, don’t swear, don’t be a jerk.

I reserve the right to edit out strong language and such. I will also delete comments that go over the line, or try to sell a product, or because I feel like it. OK, I won’t do that last part. The point is, this is my blog, and if you are being a jerk in some way I will take action. That may sound rather vague. Too bad. There is no line in the sand that says Here be good, there be jerk.

Look, when you comment on a blog, it’s like you’re in that person’s house. Be polite. Flush the toilet when you’re done, or, better yet, don’t foul the place up in the first place.

Simple, right?

I forgot to post about this! The other day, after the fam and I were out watching "I Am Legend", we saw a sundog, a bright feature in the clouds caused by ice crystals bending sunlight. I’ve written about these zillions of times.

This one was different though. When I first saw it, I thought it was the Sun! There were low clouds on the horizon, and it looked like the Sun was trying to break through them. But then I saw the actual Sun, quite a bit to the left! It was amazing. The sundog was so bright I could hardly look at it. When I put my polarizing sunglasses on, the glare went away and I was treated to a spectacular rainbow of colors where the sundog was. It was far and away the brightest one I have ever seen. I’m still kicking myself for not having had my camera with me.

Update: my bro-in-law Chris just told me he got a shot of it with his phonecam! So here it is. The sundog is on the right (partially behind the light pole), and the actual Sun on the left. This was when the sundog had already started to fade.

In olden times, sundogs were called "the false Sun". I never understood why, until this week.

NASA has decided to postpone the launch of Atlantis once more, due to work being done on the Engine Cutoff Sensors, which have been giving spurious results. The ECOs report on the amount of fuel left in the tank, and are designed to cut off the engines if the fuel runs too low.

The ECOs Hardware associated with the ECOs has been pulled out and is being worked on. NASA has not said when the Shuttle will launch again, or how this slip will affect the already overpacked schedule for the next few flights. We’ll find out soon.

As usual, Damaris has the inside scoop.

Roughly thirty bazillion people have sent me notice about this YouTube video. It was made by astronomers, and spoofs observing at the Hawaii observatory to the tune of "Hotel California" .

I am probably the last astroblogger on Earth to post this, and since Science magazine even had it in this week’s issue (click the image below for the text), I have to assume I am the last person to have actually seen it, too.

Update (January 12, 2008): The odds have now dropped to only 1 in 10,000, so the way to bet is on a clean miss by thousands of kilometers.

You may not see too many blogs phrasing it this way, but the odds of nothing happening with Mars have gone done from 99% to 96%.

2007 WD5 is a 50 or so meter wide rock heading toward Mars, and may impact the Red Planet on January 30. However, the odds of a collision are difficult to get. To find out if the two will collide, the orbit of the asteroid must be very well determined, and that’s hard. Astronomers have to get a precise location of the asteroid as it moves along its orbit, but that’s not really possible. There are errors that crop up from measuring it in the images, from distortion in the detectors, atmospheric distortion, and so on. These add together to make the position of the rock a bit uncertain that far in the future.

The position can be improved by making more observations, finding older ones (thus nailing down a longer arc of its orbit), or by simply waiting until it’s closer to D-Day.

It turns out that some older images were found that coincidentally got the asteroid in their field of view, and NASA’s Near-Earth Object Program Office was able to refine their trajectory for it: the odds of an impact have now improved slightly from 1-in-75 to 1-in-25. That may sound a lot better, but that’s only a 4% impact probability, which means a 96% chance of a miss.

Basically, what this means is that Mars is still somewhere in the fuzzy ellipse of possible asteroid positions on January 30. However, as more observations are made, that ellipse will constrict, and odds are good Mars will be outside of it. But we can’t be sure!

I’d very much like to see this thing hit. It won’t hurt us here, will only do local damage to Mars, won’t hurt the rovers or any other of our robot proxies there, and we’ll get awesome information on what happens when an asteroid impacts a planet. This has never been seen before, and it would improve our knowledge profoundly of such events, and that’s A Good Thing.

I have made many references in this blog to the cost of the Iraq "war"^* being 11 million dollars every hour. That’s a gross, vast amount of money.

And it turns out it’s wrong: it’s too low. The cost of the wars in Iraq and Afghanistan are closer to 20 million dollars per hour

Twenty. Million. Per hour. By the time it took you to read those few words, we threw $20,000 at the wars. Maybe more if you’re a slow reader.

This number comes from Ted Stevens, a man I normally wouldn’t trust with tying his shoes correctly, but I’ll note he is a Republican and used these numbers — and you can’t make stuff like this up — to ask for more money for the wars.

If you’re curious about how much that money means in real terms, go to the very scary website Cost of War… and then multiply their numbers by two, because they are based on the older war cost estimates.

I think the thing that scares me most about the "War on Terror" is how my daughter and her children and their children… will pay for it.

^*Why is "war" in quotation marks? Because I don’t remember Congress ever authorizing a declaration of war as is mandated in the Constitution.

Last week I wrote a bit about the Star of Bethlehem, and how I think it is not much more than a fish story; something that started small and has grown in significance over the millennia. I also talked about it on Coast to Coast AM last night; they had a link on their site about a Notre Dame astronomer who thinks it might have been a conjunction of planets plus a supernova.

Ignoring for the moment my own objections to this story in general (the star in the story stays in the East, which is impossible, and why do people who believe in miracles try to back them up with science, negating their entire premise?), I still have doubts over the cause. We don’t know when Jesus was born, making this a difficult proposition to start with. There were several planetary conjunctions in the time range in question (say, 8 to 2 BC), and a few comets as well.

The new thing in that article linked above is the idea that the Star may have been inspired in part by a supernova, an exploding star. The astronomer, Grant Mathews, points to a supernova remnant called Kesteven 75 as the possible culprit (note in the article that name is misspelled).

I looked up that remnant, and found a few papers. The age of the expanding gas cloud (the debris from the star’s explosion) is difficult to determine, and ranges from a few hundred to several thousand years. That doesn’t help much. However, when the core of the star collapsed, it formed a fantastically dense neutron star. This star has a strong magnetic field and spins rapidly, making it a pulsar: a star that appears to emit blips of light like a lighthouse does.

The ages of pulsars can be determined with more confidence (the rate of spin of a pulsar slows as its magnetic field sweep up material, like a parachute catching the air, and this can be used to backtrack when the star first formed). The age estimates determined for the pulsar in Kesteven 75 all converge to around 700 or so years, far too young to be the Star in the legend. While these are still estimates, and may be off by quite a bit, it’s a stretch to say this explosion could have been the basis of the Star of Bethlehem.

So I still stand by my original premise: the very fact that people are scrounging around looking for the possible cause of the Star makes it very unlikely to have been a single, real, spectacular event. Had it been such, the root source would be easier to find (and would be in several cultures’ legend and writings). This, coupled with the uncertain date of Jesus’ birth, the vague nature of Biblical writing, and the very real tendency to exaggerate such events when writing them down to increase their perceived importance, makes me think that the Star is a nice story, but very unlikely to be true. Maybe there is some basis in fact, but it’s almost certainly been puffed up over the centuries.