I found myself staring up at the sky on the night of March 13, 1989, with my girlfriend and her parents in the backyard of their house. The sky was on fire, almost literally. Red and pink sheets of plasma streamed out in a circle from directly overhead, with blue-white streaks like xenon flashes occasionally strobing across the sky. We could actually hear a sizzling, crackling sound around us. The four of us stood there, awestruck by the aurora borealis we were lucky enough to witness.
At the same time, lights were winking out a couple of hundred miles north in Québec province. The same solar storm that was mesmerizing me was causing fits for Hydro-Québec, the provincial power authority, tripping circuit breakers and wreaking havoc. This certainly wasn’t the first time the Sun threw a fit and broke systems on Earth, but it was pretty dramatic, and there are some lessons to be learned from it and other solar outbursts.
[Barry Armstead] is an astronomy enthusiast who built his own observatory in his front yard, in Canberra, Australia. It was a fine observatory as home-made observatories go, but he describes it as being small and cramped. His replacement was on an entirely different scale though, a building created by hand and which no doubt many readers would be pleased to own.
His design started with a cardboard model, and has a downstairs room upon which sits a rotatable dome with two sliding sections to form the observation window. The original observatory’s concrete pillar on which the telescope mount stood remained post-demolition, and a larger concrete pad was laid. There followed the assembly of a steel frame with a skeletal dome able to rotate on rollers, followed by cladding with steel sheet. The dome cladding was done in segments marked against the dome steelwork and cut to shape.
The final building has a fully finished interior downstairs, plus a rustic staircase to the upper deck. The concrete post has been extended, and now carry’s [Barry]’s telescope which he controls not with his eye clued to an eyepiece like the astronomers of old, but from a computer at the adjacent desk. The full construction details are on the observatory’s web site, though since it seems in danger of disappearing due to an expired hosting account we’ll also give you a Wayback Machine link direct to the relevant page. Meanwhile he offers a tour in a video we’ve placed below the break. Even a non-astronomer would find this an asset in their garden!
Continue reading “An Astronomical Observatory For Your Front Yard”
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”