Jump to content

Mr. Entropy

  • Posts

  • Joined

  • Last visited

Everything posted by Mr. Entropy

  1. Ok, I'll be honest here, I derped and didn't even consider the magnetic activity. But after a bit of reading on the subject (and finding a few potential doctoral dissertation topics in the process) I'm able to sort of prove my point, albeit in a different manner than intended. I'll admit, its a stretch, but not theoretically impossible. Turns out we're both right, sort of. It is believed that the variable phase of a red dwarf only lasts for a comparatively short period of the star's evolution, roughly 1.2 billion years out of a potential multi-trillion year life span, after which it's rotation slows and its magnetic activity weakens. For example, Barnard's star, an M-class red dwarf about 6 light years away, has little to no flare activity, the last notable flare event occurred in 1998 (although it's only been observed since 1916, so we can't say for certain how active it is. The Kepler-186 system is believed to be of similar age to the solar system, about 4.5 billion years, so it might be stable. Need to do more research. If the planet were to have formed further away from the star, and later migrate into the habitable zone after the star stabilizes, then it could in theory support Earth-like life without a magnetosphere. But that assumes that life would evolve in the same way as on Earth, which is very unlikely in this environment. In either case, a magnetosphere would be very helpful, but not necessarily required, as life could in theory evolve through natural selection to resist flares. Assuming the atmosphere wasn't eroded during the variable phase of the star's life, anyway. Even the most powerful magnetic field possible for a terrestrial planet wouldn't be enough to adequately protect the atmosphere during this time. What I'm saying is that it's not outside the realm of possibility for this planet to support some kind of life without a magnetosphere, even though a weak rotation-induced magnetic field likely exists around the planet, making the argument moot. That said, it is rather unlikely, but not impossible. Even on Earth we find things living in the most inhospitable environments imaginable.
  2. If that was directed at me, then the answer is no, because it's unnecessary. A blackbody spectrum is a measure of the intensity of wavelengths emitted by a blackbody (stars act as blackbodies) at a given temperature. It is not a measure of the intensity of radiation received from a source, so distance is not considered.
  3. Use the tool I linked to make a side-by-side comparison of the Sun (5800K) and the M1 dwarf (3500K). As you decrease the temperature of a blackbody (such as a star), the intensity of emitted radiation decreases. Dramatically. The yellow line is the blackbody curve for the Sun. The red line is for the red dwarf. Because there is little to no UV or x-ray emission, a magnetosphere/ionosphere is not necessary for Earth-like life. On Earth, the atmosphere absorbs much of the infrared radiation from the Sun, while the upper atmosphere and magnetosphere protect against higher-energy radiation.
  4. Looking at the blackbody curve (assuming a temperature of 3500K) for the star shows a peak wavelength at around 800nm, that's infrared. There's very little UV emission, and almost no x-rays or gamma rays. Most of the output is radio, microwave, and IR, with visible output mostly red-orange. Here is a tool that plots a blackbody curve for a given temperature
  5. Glad to help. But don't ignore the guys suggesting binoculars. I got started with an old pair of 7x50 binoculars that I found while cleaning my attic once several years ago. I still use them for wide field views and rough target acquisition. A decent pair of binoculars is a great companion to any telescope. As with telescopes, aperture is the main thing you should be looking at, 50mm objective lenses at minimum. Also, you might want a planisphere that covers your latitude, and there are a few great star atlases and books to guide you through the sky. Nightwatch by Terrence Dickenson is the book of choice for many amateur astronomers. You can get it dirt cheap on Amazon.
  6. I'd go with something from the Celestron Powerseeker line. Buy as much aperture as you can afford, and put it on an equatorial mount. Celestron makes it easy to do this, as equatorial mounts are designated with an EQ in the model name, and the aperture in millimeters is designated by the number. So one designated 114EQ has a 114mm aperture on an equatorial mount (also referred to as GEM, German Equatorial Mount). You definitely want the GEM, as with proper polar alignment, it will allow you to keep the object you're looking at in view as the Earth rotates underneath the "celestial sphere". A manual alt-az mount is only good for terrestrial viewing. I actually just bought a slightly-used Powerseeker 114EQ for $100 US (which if Google is right, is about your price range), and am actually quite impressed with it. The actual optics are significantly better than I was expecting, the only real complaint is that the stock finderscope is ass. But if you're smart, you can figure out a way around it's poor alignment. Just don't expect Hubble-quality views with this scope. But for $100, it's tough to beat. To get an idea of what you can expect with it, at 225x (that is, using the 4mm eyepiece without the included 3x Barlow lens) Jupiter and the Galilean (Io, Europa, Ganymede, Callisto) moons fit comfortably in the field of view. Cloud bands (dark) and zones (light) were easily distinguishable. This view was also possible at 135x (20mm eyepiece with Barlow). The Red Spot would have been visible if it was facing Earth at the time, I just didn't feel like waiting five hours.
  7. Funny enough, last weekend I was asked to teach a group of Cub Scouts some basics of astronomy for one of their activity pins (kind of like merit badges). Things like identifying bright stars and constellations, what a planet is and where to find them in the night sky, and how a telescope works. Then had them look at Jupiter and its moons Io, Europa, Ganymede, and Callisto. It's one thing for them to hear about what Galileo saw in his crude telescope. Another thing entirely to see it for themselves.
  8. Pretty damn good for a first attempt. It's too bad you can't really do anything about the chromatic aberration short of buying some incredibly expensive lenses. You might want to try taking pictures of the Moon when it's not at full phase. The shadow brings out a lot of details on features at the terminator. Plus it just looks cool. You know, like that guy up there.
  9. I say go for it. The free-return trajectory means you minimize the delta-V required, and the long voyage will give us a lot of data on manned interplanetary missions. Besides, regardless of whether it lands on Mars or not, it's still a manned interplanetary mission. Is it risky? Yes, but when has spaceflight not been risky? I'd say it's well worth the risk and money involved.
  10. In vacuum, the two balls would fall at the same rate. This was experimentally proven by Apollo 15, where a hammer and feather were dropped on the surface of the moon. An atmosphere tends to throw a wrench in the system. But this is science, you can experiment and find out for yourself. I imagine water balloons would be easier to acquire than cannonballs and yield similar results. We can talk theory all we want here, but let's get some real data to work with.
  11. The exhaust plume was visible from Daytona. NASCAR on FOX was even cool enough to point their thermal camera at it.
  12. 1. All manned missions must have LES. 2. The spacecraft is only as large as absolutely necessary. 3. If it can be reused or repurposed, then it will. 4. Redundant electrical systems are desirable.
  13. A full 25% of the Twitter accounts I follow are NASA affiliated. Really, it's no surprise I found this game.
  14. I'd like a flag with something like this for my new program, the SpaceTech Combine: Yes, my forum avatar. Other than that, go nuts.
  15. I wouldn't worry about it too much; gameplay balance tends to have a higher priority than realism.
  16. I'm not a huge fan of PDP, but I can at least recognize that having big LP channels play the game is basically free advertising. For a game whose advertising campaign is almost entirely reliant on word-of-mouth, this is a good thing.
  17. I'd paint the main fuselage like the BACC SRB (only because model rocket engines are solid fuel) with an ASAS and decoupler at the top. The nose cone would be an RC-001S RGU, NCS Adapter, and Standard NC. The fins would be AV-R8 winglets. You could also make the fuselage look like two FLT-800 tanks. You know, to make it go faster. Just remember to use the biggest possible engine you can fit in there. It's the Kerbal way.
  18. After properly installing according to the documentation, I seem to be missing more than half of the content. None of the prebuilt .craft files work due to missing parts. The decompressed archive only has 86 part files, it should be 210, right? What the hell?
  19. Is the linked file on Spaceport a complete download? I'm only getting 86 part files in the download's folder. None of the prebuilt craft work due to a lot of missing parts.
  20. I'd say its a good starting point for research if you skip the article itself and look through the citations, but you should never have a Wikipedia url in a works cited page.
  21. When you watch NASA launch coverage and catch yourself trying to open map view, rotate the camera, and/or use time warp. Guess how many times I tried to do that during the MAVEN launch yesterday.
  22. I can't believe I just tried to right-click drag the camera view on the CGI.
  • Create New...