Space has been a location of intrigue and curiosity for as long as humanity has existed.
The mysteries of the solar system are far from being fully understood, and many challenges are yet to be conquered.
For decades now, ever since humans reached the moon, the next target has been Mars.
This is what you need to know about the distance to Mars, and why we have not yet reached the red planet.
How long does it take to get to Mars?
Despite the continued efforts of Nasa, sending humans to the red planet has felt like a far-off goal - until recently.
According to the space agency, we can now expect humans to land on Mars within the next two decades.
Reaching the planet will be a feat on its own, as Mars is between 34-250 million miles away from Earth, depending on the planetary rotation around the sun.
On average, the distance between Earth and Mars is 140 million miles, according to Nasa.
If you were to reach Mars based on the current speeds of spaceships, it would take roughly nine months, according to the Nasa Goddard Space Flight Centre’s website.
Unmanned spacecraft travelling to Mars have taken anywhere from 128 days to 333 days to reach the red planet.
According to physics professor Craig Patten, of the University of California, San Diego, a trip could be shortened by burning more fuel, but it would not be advisable.
Currently, the space agency is following a five-step plan for getting astronauts there, but the likely outcome will be at least a three-year journey to and back from the planet.
What other challenges face astronauts landing on Mars?
The health of astronauts going to Mars is a major challenge for scientists and researchers for a few reasons.
According to Dorit Donoviel, director at Translational Research Institute for Space Health, the first reason is because the length of the trip.
Because astronauts will be away for roughly three years, it means that any health issues that arise must be able to be dealt with away from Earth, making even the most minor illness cause for concern.
“Having a simple kidney stone in space for example can be life-threatening,” Donoviel said. “In addition to those regular concerns that could occur in that mission, we are going to have the extremely hostile environment of the space environment and the craft. So, we are going to have to contend with situations where they are going to have to provide their own healthcare.”
Researchers must also consider the psychological effects of the journey, which will see astronauts confined to small spaces for extended periods of time.
Once humans reach the planet, they will continue to be confined to spacesuits, as the temperatures on Mars are extreme and capable of changing 170 degrees in a day.
In addition to having a temperature that is below-zero on average, the planet’s air is also largely made up of carbon dioxide.
This article was originally published in November 2019