On August 21, 2017, the moon will cast its shadow across most of North America, with a narrow path of totality tracing from Oregon to South Carolina. Tens of millions of people will have a chance to see something that the continental US hasn’t seen in ages — a total eclipse of the sun. Will you be ready?
The last time a total solar eclipse visited a significantly populated section of the US was in March of 1970. I remember it well as a four-year-old standing on the sidewalk in front of my house, all worked up about space already in those heady days of the Apollo program, gazing through smoked glass as the moon blotted out the sun for a few minutes. Just watching it was exhilarating, and being able to see it again and capitalize on a lifetime of geekiness to heighten the experience, and to be able to share it with my wife and kids, is exciting beyond words. But I’ve only got eight months to lay my plans! Continue reading “Get Ready for the Great Eclipse of 2017”
If you’ve never set up a telescope in your back yard, you’ve never been truly disappointed. The Hubble can take some great shots of Saturn, nebulae, and other astronomical phenomena, but even an expensive backyard scope produces only smudges. To do astronomy properly, you’ll spend your time huddled over a camera and a computer, stacking images to produce something that almost lives up to your expectations.
At CES, Unistellar introduced a device designed to fit over the eyepiece of a telescope to do all of this for you.
According to the guys at Unistellar, this box contains a small Linux computer, camera, GPS, and an LCD. Once the telescope is set up, the module takes a few pictures of the telescope’s field of view, stacks the images, and overlays the result in the eyepiece. Think of this as ‘live’ astrophotography.
In addition to making Jupiter look less like a Great Red Smudge, the Unistellar module adds augmented reality; it knows where the telescope is pointing and will add a label if you’re looking at any astronomical objects of note.
While I wasn’t able to take a look inside this extremely cool device, the Unistellar guys said they’ll be launching a crowdfunding campaign in the near future.
Scanning the heavens with a telescope is a great way to spend long, clear winter nights, but using a manual telescope can get to be a drag. A motorized mount with altitude and azimuth control is basic equipment for the serious observer, but adding a servo to control the focus of your telescope is one step beyond your average off-the-shelf instrument.
Having already motorized the two axes of the equatorial mount of his modest telescope as a senior project, [Eric Seifert] decided to motorize the focus rack as well. His first inclination was to use a stepper motor like he did on the other two axes, but with a spare high-torque servo at hand, he hacked a quick proof-of-concept. The servo was modified for continuous rotation in the usual way, but with the added twist of replacing the internal potentiometer with an external linear pot. Attached to the focus tube, the linear pot allows [Eric] to control the position and speed of the modified servo. Sounds like controlling the focus will be important to [Eric]’s planned web interface for his scope; we’ll be looking for details on that project soon.
We like the simplicity of this solution, and it’s a trick worth keeping in mind for other projects. But if fancy steppers and servos aren’t your thing, fear not — astrophotography is as easy as slapping a couple of boards together with a hinge.
Continue reading “Modified Servo Adds Focus Control to Telescope”
The moon’s orbit is not circular. According to Wikipedia, the moon is closest at around 357,000 kilometers and farthest at 406,000: a difference of something like 13%. That’s a freakishly egg-shaped orbit compared to the earth’s orbit around the sun, for instance. And it moves between these extremes every month.
Tonight, the perigee (the close approach) corresponds with a full moon (a syzygy — when the earth, moon, and sun are all in a line). What does that mean? A brighter-than-average full moon! If you were around for the last “supermoon” in 2011, you’ll have heard that it was the closest/brightest since 1992, or something. Well, this one’s brighter.
But don’t freak out if the clouds are hanging in the sky wherever you live; there’s a perigee full moon every 411.8 days, and there’s going to be one next year too. Unless you’re taking repeated photographs with the same lens, you won’t be able to detect the size difference with your current wetware anyway, due to the aptly named moon illusion. You already perceive the moon varying in size by a factor of 1.5 when it’s on the horizon versus hanging overhead, so an extra few percent is going to be lost in the noise floor. And the difference between a hazy and clear night will easily swamp the difference in brightness.
As usual, XKCD sums it up nicely. The “supermoon” is a perigee when the moon happens to be full. It’s a fairly frequent event, by celestial standards, and it’s underwhelming. If you want to see something really freaky, keep your eyes peeled for the total eclipse of the sun in August 2017.
Don’t get us wrong, we think that the moon is super! And there’s nothing wrong with going outside to have a peek at it. Just please, during this year’s perigee syzygy, spare us the hyperbole.
“Supermoon” versus “micromoon” comparison image courtesy [Stephan Sciarpetti].
If you are an astronomy buff, there are plenty of star maps you can find in print or online (or even on your Smartphone). But if you are a science fiction fan (or writer), you probably find those maps frustrating because they are flat. Two stars next to each other on the map might be light years apart in the axis coming out of the page. A star 3.2 light years from Sol (our sun) looks the same on the map as a star 100 light years away.
The Gaia satellite (an ESA project) orbits beyond the moon and is carefully mapping the 3D position of every point of light it sees. [Charlie Hoey] took the data for about 2 million stars and used WebGL to give you a 3D view of the data in your web browser.
Continue reading “3D Universe Theater”
A telescope isn’t an unusual thing to own if you are technically inclined. You might have even made one, at some point. However, despite improvements in optical technology and computer aiming devices, your four to twenty-inch instrument is never going to show you images like you see from big giant telescopes. The problem is, going really big requires a lot of investment in time, money, and sometimes even real estate. The big scopes get buildings constructed for them, and in exotic locations; why would you build a 24-inch scope only to try to see through the light pollution in your backyard?
Here’s an idea: take an astronomy class at a college and use their big telescope. Well, who has the time and money for that? Actually, you do. Skynet is a global network of telescopes headquartered at the University of North Carolina. As part of their mandate, they offer several tuition-free astronomy classes over the Internet. The best part? You also get free time on Skynet’s telescopes to complete your class assignments. There is a small fee (between $45 and $65) to a “benefit corporation” to administer assignments. You do get a certificate upon graduation. If you don’t want to do the assignments and you don’t want a certificate, you can still “take” the classes by simply watching them on YouTube. You can see one of the classes in the video below.
Continue reading “Skynet Takes Over…Academia?”
[gocivici] threatened us with a tutorial on positional astronomy when we started reading his tutorial on a Arduino Powered Star Pointer and he delivered. We’d pick him to help us take the One Ring to Mordor; we’d never get lost and his threat-delivery-rate makes him less likely to pull a Boromir.
As we mentioned he starts off with a really succinct and well written tutorial on celestial coordinates that antiquity would have killed to have. If we were writing a bit of code to do our own positional astronomy system, this is the tab we’d have open. Incidentally, that’s exactly what he encourages those who have followed the tutorial to do.
The star pointer itself is a high powered green laser pointer (battery powered), 3D printed parts, and an amalgam of fourteen dollars of Chinese tech cruft. The project uses two Arduino clones to process serial commands and manage two 28byj-48 stepper motors. The 2nd Arduino clone was purely to supplement the digital pins of the first; we paused a bit at that, but then we realized that import arduinos have gotten so cheap they probably are more affordable than an I2C breakout board or stepper driver these days. The body was designed with a mixture of Tinkercad and something we’d not heard of, OpenJsCAD.
Once it’s all assembled and tested the only thing left to do is go outside with your contraption. After making sure that you’ve followed all the local regulations for not pointing lasers at airplanes, point the laser at the north star. After that you can plug in any star coordinate and the laser will swing towards it and track its location in the sky. Pretty cool.
Continue reading “Star Track: A Lesson in Positional Astronomy With Lasers”