141P/Machholz
A fragmented Jupiter-family comet with multiple observed components.
141P/Machholz, also called 141P/Machholz 2, is a Jupiter-family comet that orbits the Sun once every 5.3 years. It is known for breaking apart several times, leading to multiple visible fragments.
Donald Machholz discovered the comet visually on 13 August 1994 using a 0.25-meter reflector telescope, when it had an estimated apparent magnitude of 10. Just five days later, Michael Jäger spotted a fragment 48 arcminutes northeast of the main body. Three more fragments soon turned up, labeled A through E, with A as the primary component. On 5 October 1994, component D split into two pieces separated by 7 arcseconds. The fragments formed two clusters: A and B made up the southern group, while C, D, and E formed the northern group, all linked by a dust trail. Fragment B faded quickly in November 1994, but fragment D was still seen during the 1999 apparition.
Zdenek Sekanina calculated that the first breakup happened in late 1987, about 600 days before the comet’s 1989 perihelion, creating fragment B. A second breakup around the 1989 perihelion produced fragments C and D. Fragment D then split again 600 days after that perihelion, forming fragment E, and split further during the 1994 perihelion. On 3 August 1999, Robert H. McNaught recovered fragment A at Siding Spring Observatory as a star-like object, with no other fragments visible. During the 2015 apparition, a new fragment, H, was found; initially thought to be a new comet, it was later linked to 141P/Machholz. Another fragment, I, appeared during the 2020–21 apparition. On 3 March 2021, the comet experienced an outburst, brightening by 2.8 magnitudes.
The comet’s orbit is currently stable, locked in a 9:4 orbital resonance with Jupiter. Meteor streams from 141P/Machholz crossed Earth’s orbit in the 18th and 19th centuries, but no associated meteor showers are predicted now. On 13 December 2036, the comet will pass 0.127 AU (19.0 million km) from Earth. An even closer approach is thought to have occurred on 25 December 1978, when it came within about 0.11 AU (16 million km). The comet was last observed by the Vera C. Rubin Observatory in July 2025.
Quick Facts
- Discovery Ref
- IAUC_6053
- Discoverer
- Donald E. Machholz
- Discovery Date
- 13 August 1994
- Mpc Name
- P/1994 P1, P/1999 P1
- Designations
- Machholz 2 · 1994 XXVI, 1994o
- Orbit Ref
- jpldata · MPC
- Epoch
- 30 April 2026 (JD 2461160.5)
- Observation Arc
- 26.61 years
- Obs
- 1,815
- Perihelion
- 0.807 AU
- Aphelion
- 5.305 AU
- Semimajor
- 3.056 AU
Facts from the source article.
Lore & Background
The comet was discovered visually on 13 August 1994 by Donald E. Machholz using a 0.25m reflector telescope, at an estimated apparent magnitude of 10. A few days later, on 18 August 1994, Michael Jäger reported a fragment 48 arcminutes northeast of the comet, and three more fragments were subsequently found. The fragments were designated A through E, with A being the main component. Component D was observed to split into two on 5 October 1994, with the two parts 7 arcseconds apart. The fragments formed two groups: A and B formed the southern group, while C, D, and E formed the north group, all connected by a dust trail. Fragment B faded rapidly in November 1994, while fragment D was still observed during the 1999 apparition.
Zdenek Sekanina estimated that the first breakup occurred in late 1987, about 600 days before the 1989 perihelion, creating fragment B. A second breakup around the 1989 perihelion created fragments C and D. Fragment D split again 600 days after perihelion, creating fragment E, and split further during the 1994 perihelion. Fragment A was recovered by Robert H. McNaught at Siding Spring Observatory on 3 August 1999 as a stellar object, with no other fragment visible at that time. During the 2015 apparition, fragment H was found, initially thought to be a new comet but later linked to 141P/Machholz. During the 2020–21 apparition, fragment I was found. The comet experienced an outburst on 3 March 2021, brightening by 2.8 magnitudes.
Reader's Guide
141P/Machholz is significant as a well-documented example of a fragmented Jupiter-family comet, with multiple breakup events inferred from observations of its components. The comet's fragmentation history, analyzed by Zdenek Sekanina, provides insight into the processes that can disrupt cometary nuclei. The comet's orbit is currently stable, lying in a 9:4 orbital resonance with Jupiter. Meteor streams from the comet intersected Earth's orbit during the 18th and 19th centuries, but no associated meteor showers are currently predicted. The comet made a close approach to Earth on 25 December 1978 at about 0.11 AU, and will pass 0.127 AU from Earth on 13 December 2036. Its last observation was by the Vera C. Rubin Observatory in July 2025. The comet's legacy includes the discovery of multiple fragments over several apparitions, including fragments H and I found in 2015 and 2020–21 respectively, and a notable outburst in March 2021.
Did You Know?
- The comet was discovered visually by Donald Machholz using a 0.25m reflector telescope on 13 August 1994.
- Component D split into two parts 7 arcseconds apart on 5 October 1994.
Frequently Asked Questions
Who is 141P/Machholz?
141P/Machholz is a Jupiter-family comet with a 5.3-year orbital period around the Sun, best known for repeatedly fragmenting into multiple visible pieces. It was first identified in 1994 and has been tracked by amateur and professional observers ever since.
How was 141P/Machholz discovered?
Donald Machholz visually spotted the comet on 13 August 1994 through a 0.25-meter reflector telescope while it shone at roughly magnitude 10. Just five days later, Michael Jäger independently noticed a detached fragment sitting 48 arcminutes to the northeast of the main body.
What happened to 141P/Machholz's fragments?
Shortly after discovery, observers identified components labeled A through E, with A serving as the primary nucleus. The situation grew more complex when component D itself split into two separate pieces on 5 October 1994, adding yet more fragments to the family.
When is 141P/Machholz's next close approach to Earth?
The comet is expected to make its closest approach to Earth in December 2036, passing at a distance of about 0.127 AU. That proximity should make it a notably brighter and more accessible target for backyard astronomers.
Why is 141P/Machholz important to amateur astronomers?
Its repeated fragmentation events have made it a fascinating long-term study subject, offering observers a chance to track how a small body breaks apart over multiple orbits. The fact that it was found visually with a modest 2.5-inch reflector also makes it an inspiring target for visual observers.
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