Bright and shiney space shuttle

August 7, 2005 6:21 AM

Why does the Space Shuttle appear as a bright, reflective object — almost star-like — when seen from Earth against a darkened sky? It's not exactly covered in mirrors.
posted by punkfloyd to Grab Bag (4 answers total)

Neither is the moon! But since they're light-colored their albedo is high, and most of the visible light that hits them from the Sun is reflected.
posted by nicwolff at 6:47 AM on August 7, 2005

Actually, the moon is very dark. The Sun is just that bright; if the moon was 100% reflective, it would be almost as hard to look at as the Sun during the day.

Similarly, while the whiteness of the top half of the Shuttle will reflect a lot of light and make it appear brighter than if the sunlight were reflecting off the black bottom of the ship, the main reason why it's so bright is because the Sun is really, really bright and there is a lot of contrast between the Shuttle and the surrouding black sky.

During the day when the Sun is lighting up the sky, the Shuttle is washed out by sunlight and the Moon seems much less bright, even though there's no appreciable real change in the brightness of the Moon or Shuttle.
posted by cardboard at 7:27 AM on August 7, 2005

"It's not exactly covered in mirrors."

Compared to the darkness of space, yeah, it's pretty much covered in mirrors. It'll stand out against that, y'know, albedo zero background.
posted by majick at 9:16 AM on August 7, 2005

Also keep in mind that most of the time, the shuttle orbits the earth "upside-down," with its white "upper" surface facing towards the earth and the dark "underside" facing away from it.
posted by DevilsAdvocate at 1:43 PM on August 7, 2005