By Brendan Loy
Here’s my video of the Space Shuttle Discovery and the International Space Station flying over the Rocky Mountains Tuesday night, as seen from my backyard in Denver, accelerated to 5x speed with no sound:
Below is the same video at normal speed, with sound. You can hear us — meaning me, Becky, Kristy and Myk — talking about seeing the Shuttle & ISS before the crafts actually appear in the camera’s field of view. Discovery appears at the 13-second mark, followed by the brighter ISS at the 21-second mark. Their motion appears jerky because I was using “Super Nightshot” mode on my Sony Digital Handycam; in reality, of course, they move perfectly smoothly across the sky.
That brief bit of baby fussiness you hear, incidentally, is courtesy of Loyacita, who was being held by Becky. So we actually had five witnesses to the Great Brendan’s Backyard Double Spaceship Flyover of 2009. :)
Anyway, as I mention at the end of the video, we felt very lucky to get the great view we did. A short time beforehand, the sky looked like this:
And then it started to sprinkle, just five minutes before the flyover. But when the ISS and Shuttle appeared, the rain stopped, and the clouds in the crucial area of the sky had cleared out nicely, as you can see in this enhanced version of this 23-second exposure:
The brighter portion of the line at left is the path of the ISS over the photo’s 23-second time period; the dimmer portion at right is the path of the Shuttle; and the brightest part, in the middle, shows the part where they overlapped — roughly the first 10 seconds of the Shuttle’s path, and the last 10 seconds of the ISS’s.
You can see this same effect more clearly in a tightly cropped close-up from the next photo, a 24-second exposure, revealing that the ISS was just ever-so-slightly “above” the Shuttle:
It was an awesome sight, as advertised. Let’s do it again tomorrow night! :)
P.S. If you’re wondering where the Shuttle & ISS actually were during the above video, here’s a ground plot:
So basically, they were directly over Utah and Wyoming. Tomorrow night, they’ll be further apart, but brighter because they’ll be closer to Denver (getting as close as 235 miles away, as opposed to 345 miles tonight).
P.P.S. Here are the Heavens-Above flyover information pages for Tuesday’s passes by the Shuttle and the ISS, respectively. They are shown as being 13 seconds apart in the sky, which is precisely what we observed.
On Wednesday, they’ll be more than five times further apart — 72 seconds instead of 13 — but they’ll also be four times brighter, according to Heavens-Above’s estimates of their visual magnitudes: -1.4 instead of 0.1, in the Shuttle’s case, and -3.4 instead of -1.9, in the case of the ISS. This difference of 1.5 visual magnitude units translates to 4x brighter via the formula for apparent magnitude.
UPDATE: More on tonight’s flyover in a new post here.
UPDATE 2: More flyover photos here.