Earth is the third closest planet to the Sun and is the largest and densest of the inner planets.
Earth orbits in a reasonably circular at 150 million km and is the first of the planets to have a moon.
Earth takes 365.25 Earth days to orbit the Sun and rotates once every 23 hours, 56 minutes and 4 seconds. Because it rotates around the Sun the length of a day on Earth (sunrise to sunrise) takes 24 hours.
The Earth has an axial tilt of 23.4 degrees and a diameter of 12,742km.
The Earth is thought to be 4.54 billion years old and has been accompanied by the Moon for most of that time. It is believed that the Moon was formed when a large Mars sized body impacted the Earth causing enough material to be ejected which eventually coalesced into the Moon. The Moon has had the effect of stabilising Earth’s axial tilt and is the source of the Earth’s ocean tides.
The Moon is 3,474km in diameter (27% that of Earth) and orbits at a distance of between about 362,000 to 405,000 km. It has also been affected by the gravitational pull of the Earth which has over time caused the Moon's rotation to be slowed until it matches the time it takes to orbit the Earth. This is why the same side of the Moon always faces the Earth.
Earth is protected from solar radiation by a strong magnetic field generated by movement of its core which is mainly comprised of molten iron.
The atmosphere is made up of Nitrogen (78%) and Oxygen (21%) and other trace elements (1%).
Concentrations of the greenhouse gases Carbon Dioxide, Methane and Nitrous Oxide have dramatically increased in the last three hundred years (and most markedly in the last 100 years)
The average air temperature for the planet is around 14.9 degrees C.
The temperature is rising at a rate of about 1 degree C every 50 years, and it's likely the Arctic ocean will be ice free in summers by the 2050's. Sea level is expected to rise by up 1 to 2 metres by 2100. The loss of the heat reflecting polar ice and the release of huge quantities of the powerful greenhouse gas, methane (that is currently locked up in the permafrost) are two mechanisms that are likely to considerably speed up the warming of the Earth.
Earth is a Dying Planet
Earth is the only place that we know of that has life. Unfortunately Earth's atmosphere is undergoing unprecedented rapidly rising levels of green house gases, such as carbon dioxide. The rise in temperature, along with destruction of habitat, means Earth is currently undergoing a mass extinction event in which over 1 million species are in imminent danger of extinction. UN Report.
Because of the complexity of Earth's biosphere, no one can predict the ultimate effect of the rapid changes Earth is currently experiencing. If one extrapolates from the current state of life on Earth, it is not incorrect to describe Earth as a dying planet.
With our global civilisation completely dependant on consuming resources at a faster rate each year, and political systems which are focused on short term economic goals,the Earth in the mid 21st century will be a greatly degraded as compared to the Earth of the 20th century. The advances the human race has made up to now in combating climate change have been negligible compared to the damage that has, and is still being done. Unlike when nations go to war and huge sacrifices are made (both economical and in terms of human life), politicians over the last 40 years have continually refused to take any significant action to protect the planet. The money that has been spent on combating covid-19 in the past year dwarfs all money spent on repairing the planet to date. Covid vs Climate Change. World leaders have spent this enormous amount of money because covid is an obvious enemy that is killing thousands of people now and directly impacts pending elections. The affects of climate change will, with small and increasingly large incremental steps, devastate the lives and wealth of many millions for hundreds of years to come. but (the politicians hope) not that noticeably before your next election.
In summary, our institutions cannot deal with this crisis. A radical rethink is needed of how human civilisation is structured and how it interacts with the planet. It seems very unlikely that the wheels of global politics can inact the changes needed (many of which are very simple) to reduce this crisis, and so we will have to live with an altered world as best we can. It is possible (let's hope not though) that a tipping point may occur that radically changes the climate in ways that will result in the end of the human race. That seems like a bit of a shame, but ultimately it's not really very important when considering the size and complexity of the cosmos. My only hope is that when the aliens finally visit Earth, they laugh their heads off when they reailse how we managed to destroy a paradise and wipe ourselves out with our complete obsession for wealth tokens.
Without leadership from our governments, what is the biggest single thing an individual can do to save the planet?
Eat Less Animals
...especially animals from the oceans. (Seaspiracy)