Path of the Moon

I thought this was kind of neat. Not because it's particularly exciting or insightful, just because it's something that pertains to our (semi-) every-day lives (as close as one gets when talking about astronomy, I suppose), and we (or at least I) never really think about it. Off the top of my head I wouldn't really think of the moon's orbit in this shape.

Obviously this is not to scale. But the point is that if I had drawn the moon's orbit without really thinking about it, it would have come out something like:

Which is not actually the case. The orbit of the moon is actually a thirteen-sided... uh... polygon? I don't know what you'd call it. Anyway, it looks more like a circle, to scale. You might expect it to be 12 sided, for each of the months, but due to the fact that our calendar does not perfectly match the phase of the moon, it's more like 13. Anyhow, if you tweak the parameters so that you can actually see the shape, rather than a circle, you get this:

Which seems totally counter-intuitive!

References:

Helmer Aslaksen - National University of Singapore

James Webb Space Telescope

I think we were supposed to write about a telescope. It may have been a couple weeks ago that we were supposed to do this, but hey, better late than never, right? I chose a telescope that doesn't exist yet, because what we don't have is always more exciting than what we do have.

So here's the telescope:

Or at least, what the telescope will look like. And also what the people working on it look like. It's called the James Webb Space Telescope (JWST), and should be the next big thing in space telescopes, after the Hubble Space Telescope is past its prime.

The JWST will be an infrared telescope with a 6.5 meter mirror, and will detect wavelengths between .6 and 28 micrometers.  Astronomers have high hopes that it will allow them to look even farther back (read: farther away) in the universe than we've ever seen before. It's also kind of neat in that it's actually an international collaboration (I suppose this makes sense, since we don't really have any boarders in space) between the US, Canada, and Europe (That would be NASA, CSA, and ESA, respectively).

There's a whole bunch of new technology going into this telescope, which you can read about here. I don't really want to get into all of it, but in short the design of the telescope and a lot of the pieces in it are completely new technologies. Hopefully they all work like they're supposed to!

The JWST is scheduled to launch in 2018 from French Guiana (which is on the northern-ish coast of South America). It will be orbiting about 1 million miles outside the orbit of the earth, so that it can block out any heat-noise from the earth, the sun, and the moon all at the same time.

References:
Image by NASA James Web Space Telescope - People
James Webb Space Telescope

The Drake Equation

As far as completely useless equations go, my favorite is probably the Drake Equation. This may or may not be because it's the only completely useless equation that I know. It's kind of neat, anyway. Basically, the Drake Equation (thought up by Frank Drake--he's got two first names--in 1961) is to calculate the number of detectable aliens in the universe. It goes something like:

Where 

N = number of alien civilizations

R* = avg. rate of star formation

f_P = fraction of stars with planets

n_e = avg number of life-supporting planets per star

f_l = fraction of potentially life-supporting planets that actually develop life

f_i = fraction of f_l  that actually develop into intelligent life forms.

f_c = fraction of f_i that develop technology that make it easier for us to find them

L = length of time that civilizations have had above technology

So why is it useless? Because almost all of the above are unknowns. We can get a pretty decent number for average star formation, and even for fraction of stars with planets, but the rest? So far, the only criterion for life we have is water. How many planets have water? No one actually knows. It just gets more questionable from there.

Essentially, you can turn N into whatever number you want, depending on how optimistic you're feeling that day. It's a kind of neat idea, sure. But does it actually give us any sort of useful information at all? Nope. None, whatsoever. But who cares. Because aliens. And Frank Drake is just a pretty cool name.

References:

Drake Equation: Wikipedia.org

Image from The Meta Picture