96P/Machholz

[6] It will not make another close approach to the Earth until 2028, when it will pass at a distance of 0.3197 AU (47,830,000 km; 29,720,000 mi).

[14] Machholz 1 entered the field of view of the orbiting Solar and Heliospheric Observatory (SOHO) in 1996, 2002, 2007, 2012, and 2017, where it was seen by the corona-observing LASCO instrument in its C2 and C3 coronagraphs.

[19] In these observations, its coma was substantially smaller than the Sun in volume,[citation needed] but the forward scattering of light made the comet appear significantly brighter.

It was discovered by Indian amateur astronomer Prafull Sharma in August 2012 by analyzing data from the Solar and Heliospheric Observatory, specifically the Large Angle and Spectrometric Coronagraph.

[21] Data analysis of this sort has become commonplace based on public availability of SOHO images.

[26] On February 4, 2023, the comet was recovered in the morning sky 2 degrees above the horizon at around magnitude 7.

[3] Spectrographic analysis of the coma of 96P/Machholz was made during its 2007 apparition, as part of the Lowell Observatory comet composition long-term observing program.

The only comet previously seen with similar depletion both in carbon-chain molecules and cyanogens is C/1988 Y1 (Yanaka), but it has a substantially different orbit.

[30] Other possibilities are that it formed in an extremely cold region of the Solar System (such that most carbon gets trapped in other molecules).

The following table represents future orbital elements for 96P keeping in mind that results hundreds of years in the future are highly speculative given the uncertain behavior of nongravitational forces over long time intervals and divergent solutions.

2001/2002 perihelion starmap
Starmap of 2007 perihelion
Starmap of 2012 perihelion
96P/Machholz 79 minutes before sunrise on 10 Feb 2023 (lower right of center)
Animation of 96P/Machholz around Sun - 1600-2400
96P/Machholz · Earth · Sun