Curiosity Finds a Melted Space Metal Meteorite on the Surface of Mars

Since it landed on the surface of the Red Planet in 2012, the Curiosity rover has made some rather surprising finds. In the past, this has included evidence that liquid water once filled the Gale Crater, the presence of methane and organic molecules today, curious sedimentary formations, and even a strange ball-shaped rock.

And most recently, Curiosity’s Mast Camera (Mastcam) captured images of what appeared to be a ball of melted metal. Known as “Egg Rock” (due to its odd, ovoid appearance) this object has been identified as a small meteorites, most likely composed of nickel and iron.

Egg Rock was first noticed in an image that was snapped by Curiosity on Oct. 28th, 2016, (or Sol 153, the 153rd day of Curiosity’s mission). The rover then snapped a two-frame portrait of the meteorite (seen below) two days later (on Sol 155) and studied it using its ChemCam’s Remote Micro-Imager (RMI). This provided not only a close-up of the strange object, but also a chance for chemical analysis.

Close up of Egg Rock, showing the laser reflection from Curiosity's ChemCam.  Credit: NASA/JPL
Close up of “Egg Rock”, showing the laser reflections from Curiosity’s ChemCam instrument. Credit: NASA/JPL

The chemical analysis revealed that the rock was composed of metal, which explained its melted appearance. In essence, it is likely the rock became molten as it entered Mars’ atmosphere, leading to the metal softening and flowing. Once it reached the surface, it cooled to the point that this appearance became frozen on its face.

Such a find is quite exciting, if not entirely unexpected. In the past, Curiosity and other rovers has spotted the remains of other metallic meteorites. For instance, back in 2005, the Opportunity rover spotted a pitted, basketball-sized iron meteorite that was named “Heat Shield Rock“.

This was followed in 2009 by the discovery of “Block Island“, a large dark rock that measured 0.6 meters (2 feet) across and contained large traces of iron. And in 2014, Curiosity spotted the mostly-iron meteorite that came to be known as “Lebanon” which measured 2 meters (6.5 feet) wide – making it the largest meteorite to ever be found on Mars.

However, “Egg Rock” is somewhat unique, in that its appearance seems more “melted” than meteorites spotted in the past. And as George Dvorsky of Gizmodo indicated, other aspects of its appearance (such as the long hollows) could mean that it lost material, perhaps when it still molten (i.e. shortly after it reached the surface).

Iron Meteorite on Mars. Opportunity finds an iron meteorite on Mars, the first meteorite of any type ever identified on another planet. The pitted, basketball-size object is mostly made of iron and nickel. Opportunity used its panoramic camera to take the images used in this approximately true-color composite on the Sol 339 (Jan. 6, 2005). Credit: NASA/JPL/Cornell
Image of the iron meteorite fpund on Mars by the Opportunity rover on the Sol 339 (Jan. 6th, 2005). Credit: NASA/JPL/Cornell

And such finds are always interesting because they provide us with the opportunity to study chunks of the Solar System that might not survive the trip to Earth. Given its greater proximity to the Asteroid Belt, Mars is better situated to be periodically struck by objects that get kicked out of it by Jupiter’s gravity. In fact, it is theorized that this is how Mars got its moons, Phobos and Deimos.

In addition, meteorites are more likely to survive passing through Mars’ atmosphere, since it is only about 1% as dense as Earth’s. Last, but certainly not least, meteorites have been striking Earth and Mars for eons. But since Mars has had a dry, desiccated atmosphere for all of that time, meteorites that land on its surface are subject to less wind and water erosion.

As such, Martian meteorites are more likely to be intact and better preserved over the long haul. And studying them will give planetary scientists opportunities they may not enjoy here on Earth. Now if we could just transport some of these space rocks home for a more detailed analysis, we’d be in business! Perhaps that should be something for future missions to consider.

Further Reading: ASU – Red Planet Report

“Tea, Earl Grey, Hot”… How Scientists Replicated a Mars Meteorite


Captain Picard orders tea

“Tea, Earl Grey, hot.” Who doesn’t remember that famous command by Captain Picard’s of TV’s “Star Trek: The Next Generation”? While no one’s yet invented a replicator that can brew a cup of tea out of thin air, scientists have taken in step in that direction by creating an amazing replica of a Martian meteorite using a 3D printer.

Without the fuss and expense of a sample retrieving mission to Mars, NASA scientists now have a realistic, true to life facsimile of the ‘Block Island’ meteorite discovered by the Opportunity Rover in 2009. Block Island, an iron-nickel meteorite similar to those found at Meteor Crater in Arizona, is the largest meteorite found on the Red Planet.

The real Block Island, the largest meteorite yet found on Mars, photographed by Opportunity's panoramic camera.Credit: NASA/JPL-Caltech/Cornell
The real Block Island, the largest meteorite yet found on Mars, photographed by Opportunity’s panoramic camera.Credit: NASA/JPL-Caltech/Cornell

Measuring about two feet (60 cm) across, it’s about the size of picnic cooler and weighs an estimated 1,000 pounds. The replica’s made of plastic – you could tote it around like a … picnic cooler.

Analysis of Block Island’s composition using the rover’s alpha particle X-ray spectrometer confirmed that it’s rich in iron and nickel. Scientists based the design of the plastic meteorite on detailed measurements and stereo images taken by Opportunity’s panoramic camera.

Get out your red-blue plastic glasses to get a look at Block Island in stereo. Credit: NASA/JPL-Caltech
Get out your red-blue plastic glasses to get a look at Block Island in stereo. Credit: NASA/JPL-Caltech

The rover made a 360-degree study of the meteorite five years ago taking measurements and many stereo images. But because Opportunity couldn’t see every square inch of the rock, the missing data created holes in the computer model, making it a poor candidate for 3D printing.

Last summer, scientists got around that problem by filling in the missing data and building small scale models of Block Island. To build the life-sized rock, they created depth meshes of the meteorite’s surface from six positions, then combined them into a three-dimensional digital model, according to researcher Kris Capraro of NASA’s Jet Propulsion Laboratory.

Researcher Kris Capraro (second from left) adds the finishing touches of realistic color to a model of the "Block Island" meteorite.Credit: NASA/JPL-Caltech
Researcher Kris Capraro (second from left) adds the finishing touches of realistic color to a model of the “Block Island” meteorite.Credit: NASA/JPL-Caltech

The printer built the meteorite from ABS plastic, the same material used in Lego bricks, with cord the width of the plastic line in your weed-whacker. One small problem remained before the replica could be executed – it was too big to fit in the printer’s building space. So researchers broke up the computer model of the meteorite into 11 sections. Printing took 305 hours and 36 minutes.

Researchers created each of 11 pieces in the 3D printer and glued them together to build the true-size model. Credit: NASA/JPL-Caltech
Researchers created each of 11 pieces in the 3D printer and glued them together to build the true-size model. Credit: NASA/JPL-Caltech

The sections were assembled and then painted to match the real rock. Said Capraro: “it’s the next best thing to bringing back real Martian rock samples back to Earth.”

Scientists hope someday to use 3D printing to not only replicate more Mars rocks but terrains across the solar system.