Close asteroid pass today

General physics and astronomy discussions not directly related to Celestia
Topic author
Eelco
Posts: 12
Joined: 20.12.2005
With us: 18 years 11 months
Location: Groningen

Close asteroid pass today

Post #1by Eelco » 23.02.2006, 07:14

Just as a curiosity, with todays better asteroid search programs I think I can see more small objects discovered and reported on the net, that come in the vicinity of Earth. Usually they are too small to pose any big danger even if they were on an impact course, but sometimes they come pretty close! Here is one I discovered on todays list maintained by the JPL NEO program of close approaches:

http://neo.jpl.nasa.gov/ca/

called 2006 DD1. It comes to within 0.3 Lunar Orbits so I think it shoud even be visible with a good telescope? But the speed of these things probably makes them not easy to observe, unless you have the accurate ephemeris data and computer tracking? I wouldn't know really...

Here are the Celestia orbital elements from http://neo.jpl.nasa.gov/cgi-bin/db_shm?sstr=2006%20DD1 , the period I computed from the semi-major axis to give a litle more accuracy but 3.279 is probably as accurate as it gets.. I have not yet checked the elements runing in the Celestia program. But I think it should work, just copy the code as a text file in 'Extras'. After today the elliptical orbit is not very useful anymore because gravitational effects altered it.

Code: Select all


# with JPL data, solution JPL#1
 
# 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 (2006 DD1)
# Record: 604077   SPK-ID: 3323939
# Alternate Designation: none

# OSCULATING ORBITAL ELEMENTS
# (heliocentric ecliptic J2000)
# Solution ID = JPL#1
# Epoch = 2006-02-22.0 (2453788.5) TDB




"(2006 DD1) " "Sol"
{
   Class "asteroid"
   Mesh "asteroid.cms"
   Texture "asteroid.jpg"
   Radius  0.01 # no data but guess made from H = 26.50
   EllipticalOrbit
   {
      Epoch         2453788.5
      Period            3.27948189030614 # Not all digits will be accurate
      SemiMajorAxis     2.20734253245919   
      Eccentricity      0.650018718584586   
      Inclination       8.98362282557982   
      AscendingNode     154.180189443528   
      ArgOfPericenter   63.9179846152614   
      MeanAnomaly       347.381365422583   
   }
Albedo         0.7   # fiction, large because we want it visible!!!
RotationPeriod    4 # (hours) random choice
}



Regards, Eelco

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