Astronaut Don Pettit’s latest blog entry from his current stay aboard the International Space Station (ISS) is an interesting one. Pettit, a flight engineer, describes this time of year as one of perpetual twilight for him and his fellow astronauts. Twice a year around the time of the solstices, the orbit of the ISS nearly parallels the Earth’s terminator. In his own words:
“For a period of about a week, we live in what seems like perpetual twilight, being in neither full daylight nor full night. Our orbit follows the terminator, so that the space station is constantly sunlit. From this vantage I can see both day and night simply by swiveling my head from left to right. But the night is not really dark, and the day is lit by low-angle rays from the sun.”
It almost sounds like a description of our winter except for the 24 hours of sunlight part. Pettit describes other peculiarities:
“The Moon sets in a counterintuitive way. From this vantage it moves nearly parallel to the horizon. Once I saw it slowly set, only to reappear in a few minutes. The Moon was visible for nearly the whole orbit. The night side is equally fascinating. The atmosphere on edge glows with a vibrant electric blue. Did van Gogh paint this scene? I can see at least five, maybe six distinct layers of blue—perhaps a visual display of the classic atmospheric strata.”
We can imagine Don musing out the window during his down time, because the space station is making a new series of bright passes in the morning sky The times listed below are for the Duluth, Minn. region. For your town, please click HERE and enter your zip code or log on to Heavens Above, which includes sky maps for every pass. The ISS moves from west to east and typically appears as bright as Jupiter. Its large orange-colored solar panels give the craft a yellow hue.
* Sunday morning Jan. 22 beginning at 6:16 a.m. across the northern sky. Very bright!
* Monday Jan. 23 at 6:54 a.m. similar to above
* Tuesday Jan. 24 at 6 a.m. Appears out of Earth’s shadow below and west of the North Star
* Wednesday Jan. 25 at 6:38 a.m. Another pass across the north
* Thursday Jan. 26 at 7:16 a.m. in twilight. A high,brilliant pass — peak magnitude -3.0!
* Friday Jan. 27 at 6:21 a.m. in the northern sky
* Saturday Jan. 28 at 6:59 a.m. straight across the top of the sky. Another brilliant appearance!
I wish I could say you’ll have the company of the crescent moon when you’re out ISS-gazing, but by tomorrow it’ll be too low in the east before sunrise to see from Duluth. Floridians and others in the Sun Belt might still catch a glimpse of it. The following day the moon will be new and then coast back into the evening sky.
This morning was calm, cold and very clear. Saturn’s rings and moons and Mars’ north polar cap were stunning in the telescope. As the temperature sank to -14, I watched the star Altair finally clear the treeline in the east to complete the Summer Triangle. Yes, it’s back! Anytime you want to see what the starry future holds, just look up at dawn. It’s a whole different world up there.