The Satellites that Surround Earth
Explanation:
Thousands of
satellites orbit the Earth.
Costing billions of dollars, this swarm of
high altitude robots is now vital to
communication,
orientation, and imaging both
Earth and
space.
One common type of
orbit is geostationary where a satellite will appear to
hover above one point on Earth's equator.
Geostationary orbits
are very high up -- over five times the radius of the
Earth --
and possible only because the satellite
orbital period is exactly one day.
It is usually cheaper to place a
satellite in low Earth orbit, around 500 kilometers,
just high enough to avoid the effect of
Earth's atmosphere.
The
above animated sequence starts by showing the halo of
Earth's
satellites, including the ring at geostationary, and finishes by zooming
in on the only one currently hosting humans: the
International Space Station.
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.
