Dark Skies: Turn on the Night
Explanation:
Have you ever experienced a really dark night sky?
One common and amazing feature is the glowing band of our
Milky Way galaxy stretching from horizon to horizon.
If you live in or near a big city, though, you might not know this
because city lights reflecting off the
Earth's
atmosphere could only
allow
you to see the Moon and a few stars.
Today, however, being
UNESCO's
International Day of Light, the
International Astronomical Union is asking people to
Turn on the Night by trying to better understand,
and in the future better reduce,
light pollution.
You can practice even now by going to the main
APOD website at NASA
and hovering your cursor over the
Before image.
The
After
picture that comes up is a panorama of four exposures
taken with the same camera and from the same location, showing what
happened recently in
China when people in
Kaihua County
decided to turn down many of their lights.
Visible in the
Before picture
are the stars Sirius (left of center) and Betelgeuse, while visible in the
After picture
are thousands of stars with the arching band of our Milky Way Galaxy.
Humanity has lived for millennia under a
dark night sky,
and connecting to it has
importance for both natural and cultural
heritage.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
