Tag: astronomy

Construction Photo

Posted on by Brian Garthwaite
Aerial photograph of the Observatory construction, 1963
1963: a quiet corner of campus.

Six decades ago, there wasn’t much on the south end of campus, making it an ideal place for the new Observatory. Relatively calm, not much to block the view, and few sources of nearby light pollution. A lot can change in that time.

Today’s maples and oaks – not pictured, because they were maybe saplings? – are now large enough that they block some low areas of observation and are losing limbs due to disease and age. The stadium has been wreathed by parking lots and festooned with high-intensity lights. Campus buildings have crept southward, surrounding the site. Lewisburg and its surroundings have developed, installed more nighttime lighting, and the sky has grown brighter, obscuring more of the night sky.

Clouds, however: they’re here as much as they ever were. Oh, central Pennsylvania.

Copper-coated

Posted on by Brian Garthwaite
Shiny!

Copper-coated steel BBs, used in several different labs throughout physics and astronomy. Like many of the odds and ends we use for labs and demonstrations, these aren’t used as intended by the manufacturer. In this case, one can only imagine that off-label use is actually safer.

Planetary Camera

Posted on by Brian Garthwaite
Astronomy camera on laptop
Red looks sharp on the desk, but it’s not particularly showy at night.

New semester, new classes, same old, same old around the shop. It’s not that we don’t notice the passage of time, just more that we’ve always got stuff to do. Things to sort out. Odd gizmos to tinker with.

Such as this wee little astronomy camera. (Much bigger than the camera portion of your phone, of course.) It’s a planetary camera, meaning it’s capable of a high framerate, even in low-light conditions. Unlike stars, which are effectively point sources, planets have visual size and even detail given reasonable magnification. Cool, right?

Of course, there’s this pesky but essential-for-life atmosphere in the way, and the visual wobbliness it produces – known as seeing – can make some photographs of Jupiter look like you’re peering at it from the bottom of a turbulent lake. Nicht so gut.

The simplest solution is to take a lot of pictures, sometimes compiled as a video, and select the very best ones, those moments in time when the seeing was perfect.

Of course, these cameras also work for other purposes, such as all-sky cameras to check for cloud cover at a remote location, or for meteor activity when you’d rather get some shuteye. Or, for kicks, to see one’s office through a fisheye lens.

Black and white image of a messy office.
Not debayered.
A messy office in color.
Looks even messier in color.

Ranger 4

Posted on by Brian Garthwaite
NASA press release details on the Ranger 4 launch
The rest were on white paper. Why yellow for Ranger 4?

We have several boxes of NASA press releases from the height of the space age, for the simple reason that it’s easier to pack things away than to sort and dispose of junk. None of them are worth much, really, but they can be entertaining. Take this, for example, a summary of the Ranger 4 launch. Not mentioned here, but interesting: Ranger 4 was the first US spacecraft to reach another solar system body.

By crashing into the Moon, as intended. You can read more in a brief summary by Leonard David, or by skimming Wikipedia.

Entertaining bits gleaned from the Space Activities Summary:

  • “Major Objectives Impact Moon”
  • “Major Results Impacted Moon”
  • Velocity is listed as “At lunar impact, 5,963 mph,” but can safely be assumed to be zero very shortly thereafter.
  • The “rough-land survivable seismometer” likely didn’t, although the fact that it crashed on the far side means we’ll never know.
  • There may have been “[n]o scientific data obtained,” but they did slam a space probe into the Moon, and before anyone else.

Big Dipper

Posted on by Brian Garthwaite
Pushpins in a Big Dipper shape
The backside of the bear.

A surprise discovery on a hallway bulletin board at the Observatory: a push pin Big Dipper!

It’s good and charming and subtle, and we can forgive that this version has eight stars instead of the night sky’s seven. (Not counting the visual double of Mizar and Alcor where the handle kinks.) Someone did this on a whim, and now it’s hard to resist the idea of putting up others all over campus to see who notices.

Have a great semester break!

Reticle Wire

Posted on by Brian Garthwaite
Packets of fine reticle wire
Old boxes carry neat stuff.

Making an ‘X’ across your telescope’s eyepiece is a handy thing, letting you mark the center instead of eyeballing it. There are all sorts of reasons you might appreciate that little bit of assistance, provided it doesn’t actively interfere with seeing things. So you use as fine a wire as you can. Which is going to break, of course, so keep some spares in the desk drawer.

How thin? This is AWG 53, all of 0.0007 inches thick (0.0178 mm). Enough to make even the finest human hair seem chunky in comparison.

Doppler Ball

Posted on by Brian Garthwaite
Orange foam ball on cable
The noise is more obnoxious than the color.

An electronic buzzer buried inside a foam ball, on a long cable with a switch and handle at the end. Flick the switch, and a piercing 2,500 Hz signal begins. Whirled in a big circle around your own head, the tone persists. For everyone else in the room, it creates a cyclic Doppler shift, a repeating weeee-oooo, weeee-oooo that sticks in the brain even after it’s done, like when you see phosphene images behind your eyelids after catching a glimpse of something way too bright.

We can’t overstate the wonderful modifications to the original object, back in 2010, which added the cable and switch. Your bog-standard Doppler ball – available from several scientific apparatus purveyors – requires one to open up the ball, turn on the buzzer, then close it back up. Tossing it back and forth between students illustrates the concept.

Then, when you’ve had quite enough and just want it to stop, you have to pry it open and shut the whole thing off. (This vintage version, pre-mod, required full-on battery removal.) The Doppler ball: it teaches us all kinds of new lessons!