http://neo.jpl.nasa.gov/ca/
has a detailed list of all NEOs coming close, objects within 1.0 lunar distance are luckily rare!
I made a small .ssc file of the current orbital trajectory of 2007 BD, I have not really checked yet whether it??s accurate in Celestia. Time of closest approach should be just about today. I??m assuming all the old SSC parameters still work in the latest Betas, maybe even better now with the sun in its right place! Could be a good check for accuracy whether time and distance are correct.
I calculate a few extra digits for the period from the semimajor axis, because display in Celestia seems sensitive to the accuracy of the orbital period and JPL only gives 4 digits accuracy there, on http://neo.jpl.nasa.gov/cgi-bin/db_shm?sstr=2007 BD.
Maybe of 2007 BB it would be more interesting to check whether it comes close to the moon. But haven??t made a .ssc yet of that one.
Regards, Eelco
The below text can just be pasted as an .ssc textfile in Extras to see the object in Celestia
Code: Select all
# orbital period recalculated from value
# JPL semimajoraxis with formula for two-body problem
# from Sir Isaac Newton ref
# http://en.wikipedia.org/wiki/Semi-major_axis
# http://en.wikipedia.org/wiki/Standard_gravitational_parameter
# using a sidereal year of 365.25636042 mean solar days
# and using 1 AU = 1.49597870691 x 10^11 (?± 3) m
# Asteroid (2007 BD)
# Record: 616752 SPK-ID: 3366282
# Alternate Designation: none
# OSCULATING ORBITAL ELEMENTS
# (heliocentric ecliptic J2000)
# Solution ID = JPL#2
# Epoch = 2007-04-10.0 (2454200.5) TDB
"(2007 BD) " "Sol"
{
Class "asteroid"
Mesh "asteroid.cms"
Texture "asteroid.jpg"
Radius 0.01 # no data but guess made from H = 26.42
EllipticalOrbit
{
Epoch 2454200.5
Period 0.62794362417806 # Not all digits will be accurate
SemiMajorAxis 0.73329717248984
Eccentricity 0.344647099120134
Inclination 9.27102832632698
AscendingNode 297.593323014539
ArgOfPericenter 359.149482100349
MeanAnomaly 309.96343125202
}
Albedo 0.7 # fiction, large because we want it visible!!!
RotationPeriod 8 # (hours) random choice
}