Curiosity Discovers A Hard-Boiled Meteorite On Mars / See A Super Sky Show Tonight

Can you find the meteorite? This photo was taken by Curiosity Mast camera on October 28, 2016 on Sol 1503 of its stay on Mars. A sol is Martian day which is 37 minutes longer than an Earth day. (the meteorite is at upper right). Credit: NASA/JPL-Caltech
Can you find the meteorite? This photo was taken by Curiosity Mast camera on October 28, 2016 on Sol 1503 of its stay on Mars. A sol is Martian day which is 37 minutes longer than an Earth day. (the meteorite is at upper right). Click for a large version. Credit: NASA/JPL-Caltech

NASA’s Curiosity rover just happened upon a meteorite. It’s a beauty, too. While poking around the bedrock of “Somesville” in the Murray Formation on Mars last Friday (Oct. 28), Curiosity’s color camera snapped a photo that included a small, shiny metallic meteorite. It’s about 1.6 inches (4 cm) across with an ovoid shape, hence its nickname “Egg Rock”.

Egg Rock up close! The outer surface of the meteorite melted during its passage through the Martian atmosphere. The pockets or holes may have been filled with softer, sulfur compounds that melted away during the fall. Credit: NASA/JPL-Caltech
Egg Rock up close! The outer surface of the meteorite melted during its passage through the Martian atmosphere. The pockets or holes may have been filled with softer, sulfur compounds that melted away during the fall. Compare this meteorite to a similar iron meteorite found on Earth below. Credit: NASA/JPL-Caltech

Two sols later on October 30, the rover took two closeups of the meteorite and performed a chemical analysis using its ChemCan Remote Micro-Imager. Verdict: it’s composed of metal, no doubt a mix of iron and nickel, which are the metals commonly found in metallic meteorites that fall to Earth. The lustrous, melted surface is striking and indicates that the space rock was partially melted during its high-speed passage through the Martian atmosphere.

This is a splendid example of the famous shower of iron meteorites that fell over Russia on Feb. 12, 1947 called Sikhote-Alin. It also shows regmaglypts and is composed of 93% iron and 6% nickel. Credit: Svend Buhl
This is a splendid example of the famous shower of iron meteorites that fell over Russia on Feb. 12, 1947 called Sikhote-Alin. It also shows regmaglypts and is composed of 93% iron and 6% nickel. Credit: Svend Buhl

And those lovely holes, called regmaglypts, may once have housed softer, more easily stripped away minerals that vacated the meteorite in the heat and pressure of its plunge through the Martian air. If this were Earth, the smooth, shiny texture would indicate a relatively recent fall, but who’s to say how long it’s been sitting on Mars. Mars is not without erosion from wind and temperature changes, but it lacks the oxygen and water in the air and on the ground that would really eat into a rock like this.

This rock encountered by NASA's Curiosity Mars rover is an iron meteorite called "Lebanon," similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers, Spirit and Opportunity. Lebanon is about 2 yards or 2 meters wide (left to right, from this angle). The smaller piece in the foreground is called "Lebanon B." This view combines a series of high-resolution circular images taken by the Remote Micro-Imager (RMI) of Curiosity's Chemistry and Camera (ChemCam) instrument
Curiosity found this iron meteorite called “Lebanon” back in 2014. It’s about 2 yards or 2 meters wide (left to right, from this angle). The smaller piece in the foreground is called “Lebanon B. This photo combines a series of high-resolution circular images across the middle taken by the Remote Micro-Imager (RMI). Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS/MSSS

What I find interesting is that despite Mars’ thin air (the pressure is less than 1% of Earth’s atmosphere at sea level), there’s enough atmosphere to heat and melt a metallic asteroid fragment. This isn’t the first meteorite discovered on the Red Planet. NASA’s Opportunity rover found five metal meteorites and Curiosity’s rumbled by its first find, a honking big hunk of metallic gorgeousness named Lebanon, in May 2014.

In this second view of Egg Rock, the white spots/holes are likely where the object was zapped by Curiosity's to determine what it's made of. Credit: NASA/JPL-Caltech
In this second view of Egg Rock, the white spots/holes are likely where the object was zapped by Curiosity’s laser to determine what it’s made of. Credit: NASA/JPL-Caltech

Mars is currently in the evening sky and visible as a bright, reddish “star” in the southwest well to the left of the moon this evening, but the real action is further west towards the crescent moon. Watch this evening (Nov. 2) starting about 45 minutes after sunset, when the moon pairs up with two planets: brilliant Venus and fainter Saturn. They’ll form a pretty trio in the southwestern sky. For more about this conjunction, please my article in Universe Today.

Check out the southwestern sky during mid to late twilight this evening for an eyeful of crescent moon, Venus and Saturn. Stellarium
Check out the southwestern sky during mid to late twilight this evening for an eyeful of crescent moon, Venus and Saturn. The moon stands about 3 degrees (six full moon diameters) above Saturn and 6 degrees from Venus. Stellarium