Journey to the Edge of the Solar System part 1

The Sun is a star like billions of others we see in the night sky.
It's unbelievably huge.
You could fit thousands upon thousands of Earths inside it and still have room for plenty more.
Though it's made up primarly of hydrogen and helium, the lightest elements in the universe,
it makes up more than 99% of all the matter in our solar system.
Its fusion furnace converts more than 4 million tonnes of hydrogen into helium every second.
It's more than all the energy ever produced by mankind.
On Earth we see this energy as light
and feel it as warmth.
The innermost of the planets is located just a stone's throw from the Sun.
Mercury is a small, barren and scorched planet orbiting only 50 million kilometers from the Sun.
Its proximity to the Sun renders it inhabitable for life as we know it.
For its size, however, Mercury has a very strong gravitational pull, 0.38 gees.
Its heavy metallic core makes up about 40% of its volume.
Mercury looks like a core of what was once a much larger planet.
There are different theories of what happened with the rest of it.
Mercury's rotation on its axis is very slow.
One day on Mercury is two Mercurian years long.
Such slow rotation and lack of heat conducting atmosphere
causes huge differences in surface temperature between day and night side.
The maximum temperature on the day side can reach up to 420 degrees Celsius.
while the night side is only at -160 degrees.
Our next destination is Venus,
currently located on the other side of the Sun.
Venus looks lovely from afar.
It is the brightest planet in the Solar System as viewed from Earth,
wrapped in yellowish clouds.
Known on Earth as the Morning Star and the Evening Star,
it was long believed to be a lush tropical paradise.
In the 20th century it was found that Venus is, in fact,
among the most hostile environments for life in our solar system.
Those bright clouds are made up of sulfuric acid
and the atmosphere is dominated by carbon dioxide.
Atmospheric pressure on the surface is more than 90 times higher than on the Earth
and maximum temperatures can reach up to 460 degrees Celsius.
Venus is an extreme example of global warming.
Such harsh conditions, however, do not stop futurists from envisioning ways to cololonise Venus.
With the technology that we currently possess, no permanent surface colonies can be created.
but maybe it will be possible to build floating cities high in the Venus' atmosphere,
where temperatures and atmospheric pressures are much less extreme.
Following the success of the Apollo moonlandings, a manned flyby of Venus as proposed.
The flight would have been almost a year long.
Considering the average 10-day missions to the Moon,
it would have been the most ambitious manned spaceflight ever taken.
We now jump to a marvellous blue planet.
Our homeplanet, Earth.
Past the barren and rocky Moon,
at a 150 million kilometers from the Sun,
Earth is the only planet currently known to support life.
It is the largest of the terrestrial planets in the Solar System
and orbits just the right distance from the Sun to maintain water in a liquid state
and allow life to flourish.
In fact the surface of the Earth is dominated by water.
Oceans cover more than half of the Earth's surface.
It's been more than 3 and a half billion years since the first living organisms appeared in Earth's primordial seas.
Our first ancestors first appeared about two million years ago
and modern humans have existed for about 200 000 years.
Despite the short time we've been here,
as we fly 1500 kilometers above North America,
footprints of our civilization are clearly visible.
A glittering spiderweb of city lights and street illumination highlights aereas of high population density on our planet.
But we must leave this marvel behind
and see, what other wonders there are to see and explore in our solar system.
Mars, nicknamed the Red Planet.
More than anything, this barren planet has captured the imagination
of science fiction writers, film directors and many ordinary people
Deimos, the smaller of Mars' two moons is just a small rock,
about a dozen kilometers across.
In the centuries before interplanetary probes and high-power telescopes
humans looked at Mars and saw islands, continents, seas,
cities, forests, irrigation channels and anything their imagination could think of.
The Mars we see today is a cold and dusty iron oxide desert,
covered with a thin carbon dioxide atmosphere.
The planet has long lost its magnetic field
and if it had a thicker atmosphere in the past,
it has been carried away by the hot solar wind.
Phobos, like Deimos, is probably nothing more than an asteroid captured by Mars' gravity.
Evidence that Mars has been more active in its past, are visible on its surface.
Olympos Mons is the biggest mountain in the entire Solar System,
more than 27 kilometers high and 500 kilometers wide.
The other three volcanoes are small only in comparison with Olymos Mons.
They are still far bigger than any mountain or a volcano on our planet.
Mountains are not only the huge landmarks on Mars.
This is Valles Marineris,
the largest canyon in the Solar System.
It goes on for 4000 kilometers, almost a quarter way around the planet
and would stretch all the way across Europe.
More than five kilometers deep, the canyon floor bears evidence of water flowing in it
millions of years ago.
This is it for the inner planets.
Jupiter, the innermost of the gas giants, is located three times farther from the Sun than Mars.
Between them is an asteroid belt,
a cosmic rubblefield of a planet that never formed.