Mars: Like you’ve never seen before (and it looks just like Earth)

Curiosity, a car-sized robotic rover featured in Destination: Mars, landed on the red planet in August 2012. As Curiosity makes its way across the landscape, the rover has given us one heck of a scrapbook.

First, a Selfie

Curiosity weighs 899 kilograms, is 2.9 metres long, stands 2.2 metres tall and is powered by a specially designed nuclear generator that relies on heat generated by decaying plutonium dioxide to deliver 110 watts of steady electric power.

Designed to last one Martian year (which amounts to two years on Earth), Curiosity has outlasted her original mission.

The rover talks to earth by sending radio waves from a ultra-high frequency antenna to Mars orbiters that relay the message to NASA’s Deep Space Network Antenna on Earth. It can take anywhere from 4 to 20 minutes to send a signal, depending on how far apart Earth and Mars are. 

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The rover landed on the Gale Crater, a place carefully chosen by NASA scientists. It's thought to be the site of an old lake and researchers hope to uncover signs of life there.

Curiosity travels 200 metres a day. With many stops, the rover has travelled only 15 kilometres in the last four years. 

Mars From Space

Like Earth, Mars has polar ice caps, volcanoes, canyons and deserts. This image was stitched together from a series of photos from the Viking Orbiter — one of the communications relay stations for Curiosity. 

Although Mars has much the same land mass as Earth, the planet is much smaller (about half the size).

Curiosity on the Surface

Down on Mars, Curiosity gives us an incredible panoramic 360° close up look at the Namib Dune, a giant sand dune that’s about five metres tall.

The surface of Mars here looks just like the Mojave desert in California, but it’s not nearly as warm. Mars is much further from the sun, so it has an average temperature of –60°C. A summer day near the equator may hit highs of 20°C, but it cools down dramatically at night.

This is the first time that NASA scientists have been able to study active sand dunes on another planet. The patterns reveal a familiar looking wind-swept surface. But the ripples are spaced about three metres apart, a size not seen anywhere on Earth.

Just like home, the winds on Mars travel in certain directions depending on latitude — mostly west to east. 

The Dusty Planet

Because the atmosphere is less dense, Mars is windier more often, but without the same intensity. Winds top out at about 30 metres per second, less than half the speed of hurricane force winds on Earth.  Dust devils happen frequently when the sun warms the ice-cold ground. The hot air rises quickly, pulling dust particles along with it.

Every few years, the storms get extreme, coating the entire planet in a cloud of dust for weeks at a time. NASA predicts that the planet is due for another big storm soon.

The Curiosity snapped this close-up photo of the dunes at night. The area photographed is actually 2.8 x 2.1 centimetres, so the sand particles captured are magnified. You can almost imagine sinking your toes into it.

Life on Mars?

Curiousity was sent to Mars to find out if life has ever survived on the planet. So far, the rover has confirmed that water was once part of the landscape.

This is an ancient lakebed, called the Gale Crater, a 150 km wide depression caused by an asteroid strike. Scientists know that Mars had lakes and rivers — and perhaps even an ocean, long ago. But they don’t know exactly why the water disappeared or when (although it’s thought to have been billions of years ago).

Now, it’s simply too cold; surface water would evaporate or freeze. Almost all water that exists on Mars now is ice. Ice caps are visible on the northern pole and scientists believe that much more exists locked beneath the surface.

A wider view of the Gale crater reveals how much Mars looks like Earth. The highest peak in the background is known as Mount Sharp at five kilometres high. Scientists believe Mount Sharp was created after an asteroid impact and Martian winds carved a mountain in the centre of the depression.

The Curiosity is examing Mount Sharp closely; each layer of rock reveals a different chapter in Martian history, like pages in a book.

Lower layers of Mount Sharp are made of a clay-rich rock, which is a sign that the red planet indeed had water and may have been a habitable environment for life. Higher (and newer) layers consist of drier, finer sulfate minerals. 

Curiosity's Laser Spectrometer has recorded localized burps of methane on the crater, which may have been produced by bacteria. 

Mars After Dark

The scene at sundown reveals a haze of dust that gives the sky a bluish tint. There are no postcard-perfect orange sunsets here.

The days (known as ‘sols’) are only slightly longer than a day on Earth — by about 40 minutes. Because Mars is farther away than Earth, the sun looks twice as small.

At night, the dark sky reveals two small misshapen moons that are likely asteroids that have been captured by the planet's weak gravitational pull.

In 2013, the Curiosity took photos of the two small moons eclipsing each other in an otherworldly skywatching first.

A Look Back At Home

That tiny speck is Earth, 55 million kilometres away. Depending on how close Mars’ orbit is to Earth, it’ll take at least six months to travel there. 

But thanks to Curiosity, we have a pretty good idea of what we'll find. Watch Destination: Mars on The Nature of Things.

Credit for all photos: NASA/JPL-Caltech/Univ. of Arizona