When NASA’s Curiosity Mars rover stumbled across odd-looking rock on October 27, the dark, smooth and lustrous aspect of this object, and its semi-spherical shape attracted the attention of scientists of the Mars Science Laboratory (MSL) project.

The rock, dubbed “Egg Rock,” is about the size of a golf ball and was found along the rover’s path up a layer of lower Mount Sharp called the Murray formation.

To find out more about this weird object, the rover team used Curiosity’s Chemistry and Camera (ChemCam) instrument. Basically, they zapped it with a powerful laser. Pew pew pew!


After their analysis, the team has concluded that Egg Rock is actually an iron-nickel meteorite, which is a common class of space rocks found on Earth, and sometimes on the Red Planet.

ChemCam found iron, nickel and phosphorus, plus lesser ingredients, in concentrations still being determined through analysis of the spectrum of light produced from dozens of laser pulses at nine spots on the object.

The enrichment in both nickel and phosphorus at some of the same points suggests the presence of an iron-nickel-phosphide mineral that is rare except in iron-nickel meteorites.

Iron meteorites typically originate as core material of asteroids that melt, allowing the molten metal fraction of the asteroid’s composition to sink to the center and form a core.

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