In 2012, NASA's Curiosity rover landed on Mars and it's been rolling around the surface of the planet ever since. Aside from taking samples and doing science experiments, Curiosity also has a camera attached to it. It's been discovering new things about Mars and taking some pretty awesome photos. Check them out below.
Curiosity has been making it's way all over the sparse, rocky surface of Mars, all on it's lonesome (like Wall-E) for 7 years. In it's most recent adventures, it discovered that there is salt on Mars. While Curiosity was driving across Gale Crater, a lake bed that was once full of water, the rover found sulfate salts instead of water.
The photo above shows the inside of the Gale Crater.
Scientists think that the salt appeared when a dry period evaporated the water in the lake, leaving the salts behind. The reason that lakes don't (often) dry up like this on Earth is because Earth has an atmosphere and magnetic field, both of which keep the planet wet and liveable.
The photo above shows Old Soaker, a slab of rock that has cracks on it's surface due to the pooling of water on it, and consequent drying out - leaving these strange patterns.
Billions of years ago, Mars had an atmosphere. But it always had a small magnetic field, meaning that the solar winds from the Sun eventually stripped away the atmosphere, leaving a barren, arid planet that is uninhabitable for humans - for now.
The photo above shows Squid Cove, which has similar patterns to the Old Soaker, suggesting that the water evaporation cycle happened here too.
Mars has similar seasons to Earth, because the tilt of it's axis of rotation is similar to Earth's tilt. That means that whatever hemisphere is tilted toward the sun experiences spring and summer, while the other hemisphere experiences winter and autumn. However, the years on Mars last 687 Earth days, and a season can last over 199 Earth days.
The photo above shows the floor of the Gale Crater, which is made up of extremely fine sand.
One of the starkest differences between Mars and Earth is the temperature on Mars. While the average temperature sits around -81 degrees Fahrenheit, it can dip to -225 degrees Fahrenheit. I don't know about you, but that's far too cold for me. There's also the problem of having far too little oxygen or gravity. But these conditions don't seem to bother Curiosity the rover, so keep up the photog little one.
The photo above shows the Gale Crater, taken from NASA's Mars Reconnaissance Orbiter.