The Earth - Moon Neighborhood Once we leave the Earths atmosphere we are in space. However, the Earth - Moon Neighborhood is.

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Transcript The Earth - Moon Neighborhood Once we leave the Earths atmosphere we are in space. However, the Earth - Moon Neighborhood is.

The Earth - Moon Neighborhood
Once we leave the Earths atmosphere we are in space.
However, the Earth - Moon Neighborhood is actually very crowded with
A variety of man made objects, (satellites) and a lot of natural phenomenon like
the Van Allen Radiation Belt, Near Earth Asteroids (NEA’s), also known as Near
Earth Objects (NEO’s).
There are hundreds of satellites orbiting the Earth at a variety of orbital altitudes
and inclinations. Some times there are satellite crashes, creating a lot of orbital
debris.
There are thousands of Near Earth Asteroids, of various sizes, some of which
actually pass between the Earth and the Moon. Some enter the Earth’s
atmosphere, and some actually impact the Earth (that might be why we care
about them – see the Tunguska Event).
In addition there are special locations of interest where large space structures can
be in a stable orbit in the Earth - Moon Neighborhood. These locations are called
Lagrange Libration Points (a good place for a large space structure or a colony).
S. Akerley 2011
The Earth - Moon Neighborhood
NEAs
Near Earth Asteroids
Over the last 18 Years,
More than 90 NEAs have been identified
or have passed between the Earth and Moon
Orbits. An Average of 5 per year.
It is estimated that there are about 5000
NEAs of various sizes.
Some have or will enter the Earths
Atmosphere, and some will impact the Earth..
L4
Lagrange Libration Point L4
N# Distance Designation
1000 Miles
Van Allen Radiation Belt
(30,000 to 40,000 miles)
Geo-Synchronous Earth Orbit (GEO
Approx. 22,500 miles Altitude)
Earth
L1
L2
N1
N2
N3
N4
N5
4.0
7.9
8.3
18.9
20.8
2008
2004
2008
2008
2004
TC3
FU162
TS26
US
YD5
N80
N81
N82
N83
N84
N85
N86
N87
N88
N89
N90
N91
241.7
247.2
259.1
263.7
265.5
265.5
266.5
267.4
278.4
278.4
281.2
281.2
2007
2008
2002
2007
1995
2004
2006
2008
1996
2006
2003
1991
YN1
WO2
GQ
YS56
FF
XP14
JY26
LD
JA1
BH99
XV
VG
Moon
(238,900 miles)
Space Station Orbit (LOE)
(Approx. 150 miles Altitude)
(Atmosphere ends at 65 miles Altitude)
(Hubble Telescope approx. 300 - 600 miles Altitude)
Note: Lagrange Libration Point L4 and L5
Are equidistant from Earth and Moon
At the Moons orbital distance
N79
N1 N2 N3 N4
N89
Lagrange Libration Point L5
L5
S. Akerley 2011
400 Meter Diameter
S. Akerley 2011
Close Encounters
Different types of NEA
Near Earth Asteroid
“Fly By” Encounters
S. Akerley 2011
Earth’s Gravity Well
Earth
L5
Gravity Wells
Moon
Near Earth Asteroids
(NEA)
art work courtesy of NASA
S. Akerley 2011
Review of the