But even Parker would still be short of one trillion miles (1.6 trillion km) after 224 years of travel, and still have over 24 trillion miles to go. Proxima b is 4.24 light-years away, and one light-year equates to about 9.5 trillion km (6 trillion miles). So, the journey from here to Proxima b would cover 39 trillion km (25 trillion miles) through the void. Humans have yet to reach Mars (much less Proxima b), and whether such a massive concept can ever translate to reality remains to be seen. However, landing on the Moon was seen as an impossibility only a hundred years ago—the limits of humanity are possibly boundless.