Question: What is the natural satellite of earth?
About the article "Solar System", section "Earth".

Candidate passages:
VNREDSat-1 (short for Vietnam Natural Resources, Environment and Disaster Monitoring Satellite) is the first optical Earth Observing satellite of Vietnam; its primary mission is to monitor and study the effects of climate change, predict and take measures to prevent natural disasters, and optimise the management of Vietnam's natural resources. 
The Pakistan Remote Sensing Satellite (PRS), commercially known as Remote Sensing Satellite System (RSSS) is a dual purpose Earth observational and optical satellite which is schedule to launch in 2014 for the replacement of "Badr-II" satellite. 
Satellite or satellites may refer to:  Artificial satellite  Natural satellite, an orbiting object not man-made and not in direct orbit around the Sun or another star; a moon  by analogy: * Satellite state, a dependent country * Commuter town, a town within commuter range of a larger city * Satellite campus, which is physically detached from the main campus  Satellite (software), an open source system management system developed by Red Hat  Satellite television, television service provided over Earth-orbiting satellites  Satellite radio, radio service provided over Earth-orbiting satellites  Satellite Internet access, Internet service provided over Earth-orbiting satellites  Satellite tornado, a smaller tornado that orbits around a larger "parent" tornado  Satellite Island (Tasmania), Australia  Satellite Island (Washington), USA  Satellite (biology), a sub-viral agent  Satellite DNA; also see minisatellite and microsatellite (genetics)  Plymouth Satellite, any of several car models built by Plymouth in the 1960s and early 1970s  Satellite (moth), a species of moth  Toshiba Satellite, a product line of notebook computers  Satellite (financial)  Satellite, the name for the old Domino City in the anime "Yu-Gi-Oh!
5D's"  Beta satellite, a sequence of the human genome consisting of 68-69 base pair monomeric units repeated contiguously in long arrays up to 1 Megabase in length  NES Satellite, a Nintendo Entertainment System accessory  The Satellite, a small rock peak in Antarctica  
Although no other moons of Earth have been found to date, there are various types of near-Earth objects in 1:1 resonance with it, which are known as quasi-satellites.
Quasi-satellites orbit the Sun from the same distance as a planet, rather than the planet itself.
Their orbits are unstable, and will fall into other resonances or be kicked into other orbits over thousands of years.
Quasi-satellites of Earth include , ,, and 3753 Cruithne.
Cruithne, discovered in 1986, orbits the Sun in an elliptical orbit but appears to have a horseshoe orbit when viewed from Earth.
Some went as far to nickname Cruithne "Earth's second moon".
The key difference between a satellite and a quasi-satellite is that a natural Earth satellite's orbit fundamentally depends upon the gravity of the Earth–Moon system whereas the orbit of a quasi-satellite would negligibly change if the Earth and Moon were suddenly removed since a quasi-satellite is orbiting the Sun on an Earth-like orbit in the vicinity of the Earth.
Earth possesses one known trojan asteroid, a small Solar System body caught in the planet's gravitationally stable L4 Lagrangian point.
The object, is roughly 300 metres long.
Like the quasi-satellites, it orbits the Sun in a 1:1 resonance with Earth, rather than Earth itself. 
Advanced Land Observing Satellite (ALOS), also called Daichi, is a 4-ton Japanese satellite launched in 2006.
After five years of service, the satellite lost power and ceased communication with Earth, but remains in orbit.