Depression increases your risk of a number of diseases and other conditions by, for example, increasing levels of stress hormones such as cortisol or adrenaline. Depression can affect the immune system, making it harder for your body to fight infection. Vaccinations are even less effective in people with depression.
The total surface area of the Earth is about 7008510000000000000â 510 million km2 (197 million sq mi). Of this, 70.8%, or 7008361130000000000â 361.13 million km2 (139.43 million sq mi), is below sea level and covered by ocean water.
And in the era of modern astronomy, improvements in instrumentation, methodology, and the ability to see Earth from space have certainly helped. According to modern estimates, the surface area of the Earth is approximately 510 million square km (5.1 x 108 km2) or 196,900,000 square miles. Determining this was not only a matter of ascertaining Earthâs dimensions, but also its proper shape.