As space travel gains more and more momentum, and travel to Mars seems like a real possibility, you might find yourself wondering if we can go any further.
Can we get to other planets beyond Mars? Could we one day travel to the Sun?
While the former is within the realms of possibility, but probably very very far in the future, the latter is unlikely. And that’s not just because the Sun is over 5,600 degrees celsius, and you’d likely melt about three million miles away from its surface.
Even if you managed to overcome the temperatures, the Sun’s gravitational pull makes it extremely difficult to actually get to.
While this sounds counter intuitive, since the Sun is at the centre of our Solar System and is thus central to its gravitational pull and the placement and movement of our planets, it’s pretty difficult to actually get dragged there, as NASA explain:
“It takes 55 times more energy to go to the Sun than it does to go to Mars.
Why is it so difficult? The answer lies in the same fact that keeps Earth from plunging into the Sun. Our planet is traveling very fast — about 67,000 miles per hour — almost entirely sideways relative to the Sun. The only way to get to the Sun is to cancel that sideways motion.”
So not only would you have to move very fast, you also need to get your sideways momentum just right. This would take an extreme amount of both energy and precision, and is way beyond the capacity of human space travel at this stage.
One other complexity that we’d have to overcome is the fact that we’re actually getting further and further away from the Sun over time. As an MIT research team explained to the European Geosciences Union, constant nuclear fusion gradually decreases the Sun’s mass and thus its gravitational pull. Ultimately, this means that we’re getting further away from our central star:
“As the Sun converts hydrogen into helium by nuclear fusion there is a decrease in the Sun’s mass, M and the release of energy through electromagnetic and particle radiation. The continued, steady loss of mass from the Sun results in a reduced gravitational attraction and an expansion of the orbits of the planets.”
How much further away will we be by the time that we have adequate space travel? Well, that depends on how long it takes. Currently, if it were possible, it would take around 19 years to reach the sun if the rocket you were travelling in moved at a constant speed of 550 miles per hour.
The changes to planetary orbits are currently changing by a couple centimeters per year, as the researchers go on to explain:
“Estimates of solar electromagnetic and particle flux suggest the sun is losing of order 10-13 of its mass per year, corresponding to an increase in the radius of Earth’s orbit of 1.5 cm per yr. But the Earth’s orbital velocity also decreases and since angular momentum remains conserved, the velocity is further reduced.”
So if the required technology was developed in the next few years, the extra distance would be negligable, especially with the 19 years estimated travel time taken into account.
If it took centuries – or even millennia – however, the extra distance would be much more of a factor.
Either way, space is massive and our technology is – in relative terms – in its early days.
So spoiler alert: you’re not going to be getting to the Sun any time soon.
If you think that’s impressive, check out this story about a “goldmine” of lithium that was found in the U.S. that could completely change the EV battery game.