The evening of August 5, 2012…five years ago…our Mars Curiosity rover landed on the Red Planet.
Arriving at Mars at 10:32 p.m. PDT (morning of Aug 6 EDT), this rover would prove to be the most technologically advanced rover ever built.
Curiosity used a series of complicated landing maneuvers never before attempted.
The specialized landing sequence, which employed a giant parachute, a jet-controlled descent vehicle and a daring “sky crane” maneuver similar to rappelling was devised because testing and landing techniques used during previous rover missions could not safely accommodate the much larger and heavier rover.
Curiosity’s mission: To determine whether the Red Planet ever was, or is, habitable to microbial life.
The car-size rover is equipped with 17 cameras, a robotic arm, specialized instruments and an on-board laboratory.
Let’s explore Curiosity’s top 5 discoveries since she landed on Mars five years ago…
1. Gale Crater had conditions suitable for life about 3.5 billion years ago
In 2013, Curiosity’s analysis of a rock sample showed that ancient Mars could have supported living microbes. Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon – some of the key chemical ingredients for life – in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater.
Later, in 2014, Curiosity discovered that these conditions lasted for millions of years, perhaps much longer. This interpretation of Curiosity’s findings in Gale Crater suggests ancient Mars maintained a climate that could have produced long-lasting lakes at many locations on the Red Planet.
2. Organic molecules detected at several locations
In 2014, our Curiosity rover drilled into the Martian surface and detected different organic chemicals in the rock powder. This was the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.
Curiosity’s findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.
3. Present and active methane in Mars’ atmosphere
Also in 2014, our Curiosity rover measured a tenfold spike in methane, an organic chemical, in the atmosphere around the planet. This temporary increase in methane tells us there must be some relatively localized source.
Researchers used Curiosity’s onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion.
4. Radiation could pose health risks for humans
Measurements taken by our Curiosity rover since launch have provided us with the information needed to design systems to protect human explorers from radiation exposure on deep-space expeditions in the future. Curiosity’s Radiation Assessment Detector (RAD) was the first instrument to measure the radiation environment during a Mars cruise mission from inside a spacecraft that is similar to potential human exploration spacecraft.
The findings indicate radiation exposure for human explorers could exceed our career limit for astronauts if current propulsion systems are used. These measurements are being used to better understand how radiation travels through deep space and how it is affected and changed by the spacecraft structure itself. This, along with research on the International Space Station are helping us develop countermeasures to the impacts of radiation on the human body.
5. A thicker atmosphere and more water in Mars past
In 2015, Curiosity discovered evidence that has led scientists to conclude that ancient Mars was once a warmer, wetter place than it is today.
To produce this more temperate climate, several researchers have suggested that the planet was once shrouded in a much thicker carbon dioxide atmosphere. You may be asking…Where did all the carbon go?
The solar wind stripped away much of Mars’ ancient atmosphere and is still removing tons of it every day. That said, 3.8 billion years ago, Mars might have had a moderately dense atmosphere, with a surface pressure equal to or less than that found on Earth.
Our Curiosity rover continues to explore the Red Planet today. On average, the rover travels about 30 meters per hour and is currently on the lower slope of Mount Sharp.
Get regular updates on the Curiosity mission by following @MarsCuriosity on Twitter.
