On its first try, China's Zhurong rover hit a Mars milestone that took NASA decadesSara Webb, Swinburne University of Technology and Rebecca Allen, Swinburne University of Technology
More impressively still, China is the first Mars-going nation to carry out an orbiting, landing and rovering operation as its first mission.
Planetary scientist Roberto Orosei told Nature China is “doing in a single go what NASA took decades to do”, while astrophysicist Jonathon McDowell described China’s decision to include a rover in its maiden Mars outing as a “very gutsy move”.
Where did it land?
Zhurong, named after the god of fire in Chinese mythology, separated from the Tianwen-1 orbiter and touched down close to the site of previous NASA missions, on a vast plain called Utopia Planitia.
This area of Mars was formed billions of years ago, when a martian meteorite smashed into the planet’s surface. The surrounding area is largely featureless, covered mostly in volcanic material.
Zhurong is not the first rover to explore this region. In 1976, NASA’s Viking 2 lander touched down further north within the Utopia Planitia basin, returning high-resolution images of the martian surface and analysing soil samples.
The Viking 2 lander lacked the ability to investigate any further than its initial landing site. But the Zhurong rover should be well equipped to roam farther afield during its mission.
What will it do?
The mission’s three-month scientific program will begin once the Zhurong rover disembarks from the landing craft and begins its journey across the martian surface. The 240-kilogram, six-wheeled rover is equipped with six individual scientific instruments, and has four large solar panels, giving it the appearance of a “blue butterfly”.
Zhurong’s design, instruments and technology on board Zhurong are comparable to those on board NASA’s twin rovers Spirit and Opportunity, which touched down in January 2004. Although Zhurong is not at the cutting edge of current space exploration technology, the sheer speed of this program’s development since its initiation in 2006 is awe-inspiring.
Like the many Mars rovers before it, Zhurong will probe this alien planet’s environment, and search for signs of water ice on the surface.
The mission is expected to survey four aspects of its local environmnet:
topography and geological structure
soil structure and possible presence of water ice
chemical composition, minerals and rock types
physical characteristics of the atmosphere and the rocky surface.
Zhurong will thus help build a more complete geological picture of the red planet’s history. And, in a genuine first for Martian exploration, it is equipped with a magnetometer to measure the planet’s magnetic field. This is an important study that will help address why Mars has lost much of its atmosphere, leaving its landscape so barren.
China’s growing space presence
The Tianwen-1 mission is just one of an impressive list of accomplishments by the China National Space Administration in the past year. Its other feats include launching dozens of Long March rockets, each with multiple payloads, including that of the Chang'e 5 lunar probe, which brought Moon rocks back to Earth for the first time since the end of NASA’s Apollo program in the 1970s.
Last month, China launched the first stage of its Tiangong space station, which next year is set to become the world’s second long-term home for humans in space. The momentous launch didn’t go off without a hitch, however, as debris from the launch vehicle made an uncontrolled re-entry back to Earth, eventually splashing down in the Indian Ocean.
Thankfully no one was hurt in that incident, but it is a timely reminder that China’s accelerating pace of space missions and rocket launches need to be carefully managed.
This year of activity has solidified China’s powerful presence in space, and we are only seeing the beginning of its ambitious future. By 2045, China hopes to become a leading space power, as outlined in the 2018 Aerospace Science and Technology Corporations route map.
In the coming years we can look forward to seeing China launch crewed missions to the Tiangong space station, and in the coming decades can expect to see China join other space-faring nations in missions back to the Moon and Mars.
Sara Webb, PhD candidate in Astrophysics, Swinburne University of Technology and Rebecca Allen, Swinburne Space Office Project Coordinator | Manager Swinburne Astronomy Productions, Swinburne University of Technology
Curious Kids: what does the Sun's core look like?Sara Webb, Swinburne University of Technology
What does the Sun’s core look like? Sophie, aged 8, Perth
What does the Sun’s core look like? This is a fantastic question Sophie, and one we will need to go on an adventure to answer!
We are about to take a journey to the centre of the Sun. The action begins about 148 million kilometres from our planet when we arrive at the Sun’s surface in our space ship.
It’s hot here at the surface, about 5,700 degrees Celsius, and the light is brilliant and blinding. As we look closer, the surface appears to bubble, just like boiling water. Some of the bubbles look darker than the others. The darker bubbles are slightly cooler than the rest, but every inch of the surface is still blisteringly hot.
Read more: Curious Kids: how are stars made?
From zone to zone
We continue on our journey, diving through one of these giant bubbles on the surface, and head towards our first stop: the convective zone.
Surrounding us is a hot fluid called plasma, filled with bubbles by the constant movement of hot gases rising and cool gases falling. The bubbles are moving, growing and shrinking. Some are even popping as our space ship travels down further, rocking from side to side like a boat in a high sea.
After travelling down for 200,000 kilometres (that’s about 15 times the width of the whole Earth!) the rocking finally stops. We’ve made it to our second stop, the radiative zone.
This part of the Sun is very hot. It is now 2 million degrees outside our space ship. If we could see individual light particles, called photons, we’d see them bouncing between the tiny particles, called atoms, that make up the plasma.
These bounces forwards and backwards and from side to side make up a dance scientists call a “random walk”. It can take one photon hundreds of thousands of years to randomly walk its way out of this layer.
Our spaceship is going full speed ahead, so we move through it much more quickly.
The weight of all the plasma above us pressing down means the plasma around us is denser than gold, and the temperatures are soaring up towards 15 million degrees! We have almost reached the final stop on our tour, the Sun’s core.
Read more: Curious Kids: Why do stars twinkle?
Welcome to the core
Before we enter the core, we’re going to have to shrink down to the size of an atom. It is the only way we will get to see what is happening in here, because what we are trying to see in here is atoms, millions of times smaller than a grain of sand!
The core of the Sun is home to billions and billions of atoms of hydrogen, the lightest element in the universe. The immense pressure and heat pushes these atoms so close to one another that they squish together to create new, heavier atoms.
This is called nuclear fusion. The hydrogen atoms that get squished together form an entirely different substance called helium.
So now that we are in the core of the Sun, what does it actually look like? Not only is everything blindingly bright, but it just might have a pretty pink colour!
We can’t be entirely sure what the core would look like to human eyes, but we have seen in labs here on Earth that hydrogen plasma has a pink glow. So we can make an educated guess that hydrogen plasma in the core of the Sun would look about the same.
When atoms merge together, they release large amounts of energy in the form of light. The light works its way up through the core, into the radiative zone where it bounces around, until it finally makes it into the convective zone. Then the light travels up to the surface of the Sun through massive bubbles of plasma, and from the surface it is free to travel uninterrupted through the sky.
It’s time to leave the hottest place in our solar system and head back to Earth. Our journey has taken us 700,000 kilometres deep into the interior of the Sun, past the bubbles of the convective zone, through the billions of the light rays in the radiative zone and into the mysterious atom-fusing core.
As we land back on Earth and look towards the Sun in the sky, it’s almost like looking back in time. We know now the light we are seeing was created hundreds of thousands of years ago, in the hottest place in the Solar system!