Satellites
Hi ,we are Pepa and Jessi and we want to tell you interesting things about satellites .
Satellites are so important in our lives because if they were not in orbit,
we could not enjoy many devices and applications such as mobile phones, google maps, GPS ...
we could not enjoy many devices and applications such as mobile phones, google maps, GPS ...
But what are satellites used for? We use satellites for the following
Television
Satellites send television signals directly to homes, but they also are the
backbone of cable and network TV. These satellites send signals from a
central station that generates programming to smaller stations that send the
signals locally via cables or the airwaves. "At the scene" news
broadcasts, whether live reporting on a vote at the Capitol or from the scene
of a traffic accident, are sent from the field to the studio via satellite,
too.
Telephones
Satellites provide in-flight phone communications on airplanes, and are
often the main conduit of voice communication for rural areas and areas where
phone lines are damaged after a disaster. Satellites also provide the primary
timing source for cell phones and pagers. In 1998, a satellite failure
demonstrated this dependence; it temporarily silenced 80 percent of the
pagers in the United States, National Public Radio was not able to distribute
its broadcasts to affiliates and broadcasted only via its website, and on the
CBS Evening News, the image of Dan Rather froze while the audio continued.
Navigation
Satellite-based navigation systems like the Navstar Global Positioning
Systems (known colloquially as GPS) enable anyone with a handheld receiver to
determine her location to within a few meters. GPS locators are increasingly
included in in-car direction services and allow car-share services like Zipcar
to locate their cars. GPS-based systems are used by civilians and the military
for navigation on land, sea, and air, and are crucial in situations like a ship
making a difficult course in a harbor in bad weather or troops lost in
unfamiliar territory, where other navigation tools may not exist.
Business & Finance
Communications satellites have the ability to rapidly communicate between a
number of widely dispersed locations. This is an important tool, allowing
big manufacturing companies and department stores to perform inventory
management, provide instant credit card authorization and automated teller
banking services to even small towns, pay-at-the-pump gas at freeway gas
stations, and video conferencing for international corporations.
Weather
Satellites provide meteorologists with the ability to see weather on a
global scale, allowing them to follow the effects of phenomena like volcanic
eruptions and burning gas and oil fields, to the development of large systems
like hurricanes and El Niño.
Climate and Environmental
Monitoring
Satellites are some of the best sources of data for climate change research. Satellites
monitor ocean temperatures and prevailing currents; data acquired by
satellite-borne radars were able to show sea levels have been rising by three
mm a year over the last decade. Imaging satellites can measure the
changing sizes of glaciers, which is difficult to do from the ground due to the
remoteness and darkness of the polar regions. Satellites can determine
long-term patterns of rainfall, vegetation cover, and emissions of greenhouse
gases.
Safety
Earth observation satellites can monitor ocean and wind currents as well as
the extent of forest fires, oil spills, and airborne pollution; together this
information helps organize emergency responders and environmental
cleanup. Satellites can take the "search" out of "search
and rescue" for people in distress in remote regions. Distress radio
beacons directly linked to a search and rescue satellite can lead rescuers
quickly and accurately to a land, sea, or air emergency location.
Land Stewardship
Satellites can detect underground water and mineral sources; monitor the
transfer of nutrients and contaminants from land into waterways; and measure
land and water temperatures, the growth of algae in seas, and the erosion of
topsoil from land. They can efficiently monitor large-scale infrastructure,
for example fuel pipelines that need to be checked for leaks, which would
require enormous hours of land- or air-based inspection. Imaging
satellites produce high-resolution data of almost the entire landmass on earth;
such data used to be a closely guarded military capability, but now, nearly
anyone with an internet connection can find his house using Google Earth.
Development
Satellites are increasingly important to the developing world. For a
country like India, with populations separated by rough terrain and different
languages, communications satellites provides remote populations access
to education and to medical expertise that would otherwise not reach
them. Earth observation satellites also allow developing countries to
practice informed resource management and relief agencies to follow refugee
population migrations.
Space Science
Before the Space Age, astrophysicists were limited to studying the universe
via ground-based telescopes, and so could only use information from the parts
of the electromagnetic spectrum that penetrated the Earth's
atmosphere. Many of the most interesting phenomena are best studied at
frequencies that are best or only accessible from space—satellite telescopes
have been critical to understanding phenomena like pulsars and black holes as
well as measuring the age of the universe. The Hubble Space Telescope is
arguably the most valuable astronomical tool ever built!
But
satellites not only have good things ,in the space there are most than 5000
satellites , This is the reason that there is so much space junk but it isn´t the only
negative thing ,in the world there are millions and millions of
people dying of hunger and
wars and grabbing some comfort to us we
could get a lot of these people live in a
state of equality with the more
developed countries
