# data[].attributes.headline
Orbit - a closed path around which a planet or satellite travels

# data[].attributes.subject
Orbit - a closed path around which a planet or satellite travels

# data[].attributes.body
Two describe size and shape
Three describe orientation
One describes location within orbit
Plus time stamp

# data[].attributes.body
(e)
describes the roundness
a - semi-major axis
b - semi-minor axis

e = 0 - circular orbit

e > 1 - not a complete orbit (non-closed orbit)

# data[].attributes.body
(a)
describes the size of the ellipse
half of the largest diameter
from the center (most likely not central body)

Apogee - point of orbit farthest from Earth
Perigee - point of orbit closest to Earth
Altitude - distance from surface of Earth to either of these
in circles, apogee and perigee are the same and are undefined
Earth radius - 6378 km
Gravitational Constant = 6.67*10^-11 m^3/kg*s^2
Mass of Central Bodies - (M) = 5.98*10^24
Only orbital parameter that determines the orbital period (T) = calculated in seconds

# data[].attributes.body
(i)
Angle between Earths' equatorial plane and the plane of the orbit
height of inclination is the height of the ground trace

# data[].attributes.body
(RAAN, Ω)
the rotation or twist about the earth (yaw)
angle measure along equatorial point in space (Vernal equinox) and the point where the motion is from south to north across the equator (ascending node)
measured in degrees
Ascending - from south to north (up)
Omega = 0 when ascending node is aligned with vernal equinox

# data[].attributes.body
(funky w)
describes the orientation of the apogee and perigee
angle from the ascending node to the perigee point
measured in degrees (0 < w < 359)
only exists when perigee exists

# data[].attributes.body
(v, but it's a oopsulawn)
once orbit completely described, satellite's location on that orbit
measured in degrees
perigee = 0 degrees
apogee = 180 degrees

# data[].attributes.body
describes when the set of values was accurate for the satellite (snapshot)

# data[].attributes.body
given ground trace, period and inclination can be found
top or bottom degree = inclination
the trace gap = way to determine orbit period
4 minutes per degree
gap degrees * 4 = period (T)

# data[].attributes.body
Satellites travel around Earth in an elliptical path. Earth at a foci

# data[].attributes.body
A line drawn between Earth and a satellite will sweep out equal areas during equal time periods anywhere along the orbit
At the perigee a satellite is moving the fastest
At apogee a satellite is moving the slowest

# data[].attributes.body
The time it takes to complete an orbital period is related to it's semi-major axis