Comet 96P/Machholz returns – Watch it on LASCO and STEREO


Between July 12-17, 2012, comet 96P/Machholz will be visible in the SOHO LASCO/C3 field of view and will brighten to about magnitude +2. Also, it should be visible from both STEREO A and B between July 13-15 and it comes to perihelion on July 14, 2012. The comet will not make another close approach to the Earth until 2028, when it will pass at a distance of 0.319 AU (47,700,000km; 29,700,000 miles).



96P/Machholz (or 96P/Machholz 1) is a short-period comet with an estimated radius of around 3.2km, and a high inclination with respect to the plane of the solar system. It’s highly eccentric 5.2 year orbit has the smallest perihelion distance known among numbered/regular short-period comets, bringing it considerably closer to the Sun than the orbit of Mercury. 96P/Machholz was discovered on May 12, 1986 by amateur astronomer Donald Machholz on Loma Pieta peak, in central California using 130 millimetres (5.1 in) binoculars. It is the only known short-period comet with both high orbital inclination and high eccentricity. In 2007, Machholz 1 was found to be both carbon-depleted and cyanogen-depleted, a chemical composition nearly unique among comets with known compositions. The chemical composition implies a different and possible extrasolar origin. The high inclination of Machholz 1’s orbit, 59°, suggests that it could come from the Oort Cloud rather than the Kuiper Belt, which is the source of most short-period comets.

Orbital Elements

The following orbital elements are taken from MPC 79654:

Epoch 2012 July 12.0 TT = JDT 2456120.5
T 2012 July 14.7859 TT MPC
q 0.123792 (2000.0) P Q
n 0.1866097 Peri. 14.7561 -0.2063780 -0.4875060
a 3.032819 Node 94.3243 +0.7892381 -0.5954430
e 0.959183 Incl. 58.2988 +0.5783696 +0.6385809
P 5.28
From 638 observations 1988-2012, mean residual 0".6. Nongravitational
parameters A1 = -0.02, A2 = -0.0001.

JPL Small-Body Database Browser

Elements and Ephemeris for 96P/Machholz (Minor Planet Center)


The Unusual Spectrum of Comet 96P/Machholz

Transits of Objects through the LASCO/C3 field of view (FOV) in 2012


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    1. There is one genious guy called Ian Musgrave from Australia that runs excellent (CHECK IT OUT). He made a file for Celestia and this is his tip: Just copy the text below into a file called Machhholz.ssc then save it into the extras folder
      ==============>8 cut here===Machholz.ssc===>8 cut here============
      “Machholz 1:96P” “Sol”
      Class “comet” # Just copying the data for Halley
      Mesh “halley.cmod”
      Texture “asteroid.jpg”
      Radius 3 # best guess at maximum semi-axis
      MeshCenter [ -0.338 1.303 0.230 ]

      Epoch 2456060.5 #2012-May-13
      Period 5.2809388447549
      SemiMajorAxis 3.032508014411316
      Eccentricity 0.9591780641569885
      Inclination 58.29867634073911
      AscendingNode 94.32408165126535
      ArgOfPericenter 14.75604312882846
      MeanAnomaly 348.2820814381255

      # Again, this data is copied straight from the ssc files for Halleys’ Comet
      # chaotic rotation, imperfectly defined:
      # this version from “The New Solar System”, 4th Edition; Eds.
      # JK Beatty, CC Petersen, A Chaikin
      Period 170 # 7.1 day axial rotation period
      Inclination 66
      PrecessionPeriod 3457004.12 # 3.7 day precession period

      Albedo 0.8

      Hope this will help!
      Don’t forget to check up his blog – there are great stuff there!

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