Monday, July 25, 2011

Mars attacks, every year

It's time for the Mars hoax email again. You may get email that says that Mars will appear as big as the full Moon, or even There will be two moons in the sky, and with a date, like August 27th. It comes from the 2003 Mars opposition announcement. In late August of 2003, Mars had a particularly close opposition, and in a telescope at 75x, Mars appeared as big as the Full Moon does with the unaided eye. Each summer, the email gets modified a bit more, and is pretty far from reality.

Mars doesn't get real close to the Earth every summer. Not even once a year. The next close approach is in March of 2012. Mars closest approaches that happen in Augst or September are the closest that they get. The March event won't be particularly good. But it will be worth a look.

At the moment (late July 2011), Mars is a morning object, and the visual diameter is 4.4 arc seconds. One must magnify Mars by about 400x to bring it to the visual size of the Full Moon. Fairly large back yard telescopes can achieve this. Perhaps an eight inch (200 mm) or ten inch (250 mm) diameter telescope would perform OK at this magnification. However, the atmosphere needs to be really steady to get a good view. One can expect a brief really still view about once every five minutes.

And then, you'd get a view with the kind of detail you can see on the Moon. That is, you'd see the largest areas of light and dark. No craters or mountains. For Mars, this may include a polar cap, and shades of orange. Waiting until March will give you views that are about 4 times larger in any given telescope.

The closest views of Mars at the moment can be downloaded over the Internet. They come from a rover that is on Mars - Opportunity. The twin cameras give a very human like stereo view, in color (multiple images are taken with red, green and blue filters, which combine to make color images). Further, there's a microscope, which can take images that can show detail to something like a 20th of a millimeter.

There is something about using your eyeball and a telescope and seeing it for yourself. It's different. There's still a month or so of Saturn's big show this summer. So get out to your local astronomy club's next event and take a look.

Tuesday, July 19, 2011

the possible future of cars









Friday, July 01, 2011

Generic terms

One of the job titles that's pretty common is Systems Specialist. What does it mean? The word Systems is pretty generic. The solar system is a system. The one we live in has a star, some planets, asteroids, comets, and so on. So a Planetary Scientist is a Systems Specialist, right? But i work in Information Technology (IT), which is another overly generic title, but which is nearly always taken to have something to do with computers. So what is a Systems Specialist in terms of computers? Well, computers have parts too. There's the thing that actually processes data, the Central Processing Unit (CPU). There's at least one of them in every computer. But there's also specialized memory called cache, Random Access Memory (RAM), disk, networking, and various other devices. That's a computer system. Computer systems come in a number of varieties. Sometimes the same hardware can run very different software. For example, the exact same hardware might be able to run MS Windows, Linux or Apple Macintosh operating systems. So the same hardware might have very different personalities. And a Systems Specialist might not be a specialist in all of them. What kind of Systems is this person a Specialist in? Why not say Unix Systems Specialist, or whatever? Then examine the word Specialist.

When i'm asked what i do for a living, it is often the case that i'm talking to someone who doesn't do what i do. I assume they don't know the details of computers at first. So i don't launch into the details unless asked. I say, "I do something with computers". It's pretty generic. I've been asked what my job title is, and i tell them. But when they ask me what that means, and it's as generic as Systems Specialist, the only really good answer is "My job is so secret, not even i know what i'm doing".