This Fourth
of July weekend will be filled with dazzling fireworks displays for many
Americans, but not for NASA astronaut Michael Barratt, who is flying high above
Earth on the International Space Station.
Barratt is the
only American on the space
station's six-man crew, which includes two Russian cosmonauts and astronauts
from Japan, Canada and Belgium. But while astronauts can see an amazing amount
of detail on the Earth from the station's unique vantage point, spotting the
traditional U.S. Independence Day fireworks is not among them.
"It's
beyond the capability of human eye apparently to see manmade fireworks from orbit,"
NASA spokesperson Kelly Humphries told SPACE.com. "It's 200 miles away,
you know."
The space
station orbits in the Earth at an altitude of about 220 miles (354 km). It can
easily be seen as a bright, fast-moving light in the night sky by the unaided
eye. NASA said this Fourth of July weekend will offer many Americans a chance
to see
the station for themselves if weather permits. SPACE.com's Satellite
Spotting Guide has full details.
From its
orbit, the station is close enough to Earth that astronauts can spot the
pyramids of Egypt and large ships on the ocean, but too high up to see Fourth
of July light shows. The station's most recent American skipper Michael Fincke
of NASA said he was unable to spot the trademark New Year's Eve fireworks that
marked the start of 2009 around the world, Humphries said. Fincke commanded the
station from October 2008 to last April.
Lightning,
which astronauts can see flashing in clouds during thunderstorms, can make for
a natural stand-in for artificial fireworks, Humphries said. Fireworks and
other open flames are not allowed inside the station's main cabin as a safety
measure, though astronauts can
light fires inside a special sealed box as part of an ongoing science experiment.
Many
manmade structures are visible from Earth orbit, among them cities, highways
and some of the vehicles that traverse them.
The Great
Wall of China is visible from orbit, but can be an elusive target since it
easily blends in with the background scenery when seen from the space station, astronauts
have said. Former NASA astronaut Leroy Chiao listed his view of the Great Wall as
one of his 10
favorite photographs from the more than 24,000 images he took while
commanding the station's Expedition 10 mission between 2004 and 2005.
No human
constructs are visible from the moon, which is about 238,900 miles (384,402 km)
from Earth on the average.
While Barratt
may not get a chance to see fireworks, he will be able to spend some time with
his family through a video or radio link, Humphries said. The father of five
from Camas, Wash., and his fellow station crewmates will have some free
off-duty time to contact their respective families or rest this weekend in
addition to their regular schedule of station cleaning, exercise and planning
conferences.
"They've
got time off to enjoy the day," Humphries said.