It’s been a year since we waited the seven minutes of terror for the landing of the most sophisticated Mars rover we’ve ever engineered. In the 365 Earth days since that historic landing, the Mars Science Laboratory – known as Curiosity – has performed some amazing science and inspired countless people.
Curiosity is big. At 2,000 pounds, even landing on the planet in one piece was a marvel of modern engineering. For comparison, the Spirit and Opportunity rovers weigh in at 410 pounds each. Because Curiosity is so big, it couldn’t just bounce along the ground, ensconced in airbags, which is how Spirit and Opportunity landed. Instead, NASA used the sky crane to lower the rover to the Martian surface. This was risky. Because conditions on Earth are so different from those on Mars, it was impossible to test. As we all know, it ended spectacularly.
However, we didn’t just devise a new method of landing a gigantic, nuclear powered vehicle on Mars just to prove we could. Curiosity had major exploring to do!
Image credit: NASA/JPL-Caltech/MSSS and PSI
Near its landing site, Curiosity discovered something so familiar, yet incredibly exciting: rounded pebbles, ranging in size from a grain of sand to a golf ball. This simple discovery indicated that, sometime in Mars’ ancient past, the planet played host to flowing streams. After studying the pebbles, NASA scientists determined that that location was probably once home to a shallow stream that ran about three feet second.
Formerly Thick Atmosphere
Curiosity has also been analyzing the Martian atmosphere over the past year and has helped us figure out that, while the atmosphere may once have been thick like Earth’s, it hasn’t been in about 4 billion years. You see, there are certain isotopes (basically, atoms with some extra neutrons in the nucleus) that scientists can look for when analyzing the atmosphere. In this case, Curiosity detected higher concentrations of those telltale isotopes, which is evidence that most of the atmospheric gases have escaped. We don’t really know why the atmosphere escaped from Mars and not from Earth, but it could have something to do with a planet’s magnetic field. A magnetic field protects a planet from solar wind particles which can strip away an atmosphere. Earth has a magnetic field. Mars does not.
To Methane, or Not to Methane
Image credit: NASA/JPL-Caltech/MSSS
Sometimes it’s not what you find on your exploratory expedition. It’s what you don’t find. In measurements from Earth we’ve found hotspots of methane on Mars. On our little blue planet, the majority of methane comes from biological activity like cow farts, but it can also be created from interactions between rocks and water. If Curiosity had found methane, it could have indicated microbial life or geologic activity, which would overturn current thinking.
Curiosity has sniffed the atmosphere and has found no definitive evidence of methane. That, however, doesn’t mean it doesn’t exist. It’s possible that the gas is only produced during certain seasons and disappears quickly. It’s possible that Curiosity just missed it this time around. Only time will tell.
Excitement for Science
A renewed excitement for space exploration and science in general is probably my favorite side effect of the Curiosity mission. People got into it! Over three million people watched the Curiosity landing via the Internet, and almost two million watched on television. A thousand people gathered in Time Square to watch it live, as well. As of this writing, the Curiosity rover Twitter account has 1,373,719 followers. It could just be the circles I run in, but there’s a static in the air. People seem to care about planetary exploration in a way they didn’t before Curiosity. Mars is now in the popular conscience. There was talk of a reality show, for crying out loud!
Even if we don’t find any little green men, if this is the legacy of Curiosity, I’ll take it.
Happy birthday, Curiosity!
Photo Credit: NASA, JPL-Caltech, MSSS - Panorama by Andrew Bodrov