# Mandjet Chasma

**Mandjet Chasma** is a large canyon system, or chasma, on [Charon](https://www.edgepedia.org/charon-moon), Pluto's largest moon, named for the Egyptian boat that carries the sun god Ra across the sky in the daytime. The International Astronomical Union adopted the name on April 11, 2018.<sup>[1](https://planetarynames.wr.usgs.gov/Feature/15733)</sup>

| Key fact | Detail |
|---|---|
| Target and type | Chasma (canyon) on Charon, feature ID 15733 in the Gazetteer of Planetary Nomenclature<sup>[1](https://planetarynames.wr.usgs.gov/Feature/15733)</sup> |
| Size | IAU diameter 385 km; geological mapping gives a length of at least 450 km and a typical width of 30 km<sup>[1](https://planetarynames.wr.usgs.gov/Feature/15733)</sup><sup> • </sup><sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup> |
| Location | Centered at 4.80° N, 294.40° E (planetocentric, east-positive), spanning latitudes from −4.50° to 10.60°<sup>[1](https://planetarynames.wr.usgs.gov/Feature/15733)</sup> |
| Depth | Walls plunge 5–7 km from the surrounding plains to the floor; a Science report describes it as fault bounded and reaching about 7 km deep<sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup><sup> • </sup><sup>[3](https://www.sciencemagazinedigital.org/sciencemagazine/18_march_2016?pg=103)</sup> |
| Name origin | Egyptian boat that carries the sun god Ra across the sky in the daytime; ethnicity listed as Egypt<sup>[1](https://planetarynames.wr.usgs.gov/Feature/15733)</sup> |
| Approval | Adopted by the IAU on April 11, 2018<sup>[1](https://planetarynames.wr.usgs.gov/Feature/15733)</sup> |

## Discovery and identification

Mandjet Chasma was not identified in the first [New Horizons](https://www.edgepedia.org/new-horizons) geologic descriptions because it lacks a sharp topographic rim. It emerged from initial stereoscopic topographic analysis published by Jeff Moore and colleagues in 2016: its rim is a gentle slope, with the walls transitioning from the surrounding plains before plunging 5–7 km to the floor.<sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup> The Long Range Reconnaissance Imager (LORRI) on New Horizons captured a perspective view of the chasma looking westward toward Charon's limb, in which Mandjet extends from the lower left of the frame to the limb at the upper right; the scarp south of it bounds the smooth plains of Vulcan Planum.<sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup>

## Setting in Charon's tectonic belt

Mandjet lies within the belt of extensional tectonic features that crosses Charon's northern terrain, Oz Terra. A 2017 modeling study grouped Mandjet, Macross, and Serenity chasmata, and possibly [Argo Chasma](https://www.edgepedia.org/argo-chasma), as a global-scale assemblage of intermittent chasmata following a similar trend, and argued that contraction and expansion episodes in Charon's history may have provided the extensional environment needed to form such a belt.<sup>[4](https://academic.oup.com/mnras/article/468/1/1056/3061365)</sup> The roughly east-west alignment of the major chasmata implies north-south extension across the structural belt, and the extension is inferred to be ancient, up to about 4 billion years, based on the superposition of many craters and the resurfaced units of Vulcan Planum, which bury the rift flanks.<sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup>

## Contribution to Charon's extension

The rift geometry of Serenity and Mandjet Chasmata allows an estimate of the crustal extension across them. Assuming the bounding normal faults dip steeply, about 60°, the rift depth approximates the extension across it. Taking Serenity Chasma as 300 km long with a minimum depth of 3 km and Mandjet as 450 km long with a depth of 5 km, the two together represent an areal increase of about 3,000 km², an areal strain of roughly 0.3% over the northern half of Charon's encounter hemisphere.<sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup> Adding the 23 other largest scarps in Oz Terra pushes the minimum areal strain estimate to about 1%, with the four longest structures, including Mandjet's 450 km, contributing 46% of the extensional area; the authors link this early strong extension to the apparently cryovolcanic resurfacing of Vulcan Planum to the south.<sup>[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)</sup>

## References

1. [Mandjet Chasma, Gazetteer of Planetary Nomenclature, USGS Astrogeology Science Center](https://planetarynames.wr.usgs.gov/Feature/15733)
2. [Beyer, R. A. and colleagues (2017). Charon tectonics. Icarus (PMC5599803)](https://pmc.ncbi.nlm.nih.gov/articles/PMC5599803/)
3. [Science Magazine, 18 March 2016 (The Geology of Pluto and Charon)](https://www.sciencemagazinedigital.org/sciencemagazine/18_march_2016?pg=103)
4. [Desch, S. J. and Neveu, M. (2017). Contraction/expansion history of Charon with implications for its planetary-scale tectonic belt. Monthly Notices of the Royal Astronomical Society 468, 1056](https://academic.oup.com/mnras/article/468/1/1056/3061365)

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*Topic: Encyclopedia › Places and geography › Extraterrestrial places › Planetary surfaces and named features › Pluto and Charon surface features*

*Initially written Oct 21, 2026*

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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license