Pluto as seen by the New Horizons spacecraft in 2015 at a distance of 766.048 kilometers - NASA
Profile
Name
Pluto
planet type
gas planet
Number of moons
5
Distance to the Sun
approx. 6,900,000,000 km
Orbital period around the sun
248 years
Distance to Earth
approx. 6,900,000,000 km
Diameter
2,368 km
Temperatures at the surface
-240°C to -210°C
Mean surface temperature
-240°C
Atmosphere
Nitrogen, carbon monoxide
Frequent elements
Water, methane
For years, Pluto was the ninth planet in our solar system. Pluto was the smallest in our planetary family and is also the furthest from the Sun.
But since 2006, Pluto no longer has planet status because it does not meet the most important planet criterion. This is because a planet must clear its surroundings of all material in the course of its development and be the leading object in its orbit. Unlike our Earth and the other planets in our solar system, Pluto has unfortunately not managed to do this. In fact, there are many similar planets in its orbit besides it. But because it has accumulated so much material over time and become a sphere, it has nevertheless fulfilled a planetary criterion. The planet Pluto now falls into the category of dwarf planet.
The gravitational pull is 6 times less than on Earth.
Earth's moon is the 5th largest moon in the solar system.
It always turns the same side towards us.
How did the moon come into being?
50 million years ago, a planet about the size of Mars grazed our Earth. This dislodged large quantities of rock, which were hurled into space. This debris gathered in orbit around the Earth and gradually clumped together to form a sphere - our moon. Since then, the moon has been moving in our orbit around the Earth. It is an integral part of our lives and an important companion for the Earth.
The phases of the moon
Have you ever wondered why the moon always looks different?
This is because it orbits the Earth, reflecting light from the Sun. So how we see the moon from Earth depends on how the sun, moon and Earth are currently positioned in relation to each other. The different appearances of the moon are called lunar phases. It goes through them all within 29½ days. The individual moon phases are called as follows:
New moon (not visible) waxing moon Full moon waning moon
The lunar surface
The moon gets its grey colour from a thick layer of dust that covers its surface. This dust is the result of meteorites that have disintegrated.
Dark areas
are also called seas.
can be seen with the naked eye.
are made of dark basaltic rock.
Moon crater
can be 1 to 2,000 kilometres wide.
do not weather, but persist.
are formed by impacts of meteorites.
are divided into 3 categories:
Wall plains: Impact traces 100 to 300 kilometres in diameter.
Craters: 10 to 100 kilometres in size.
Small craters: 10 to 20 kilometres in size.
Grooves
occur in 2 different types:
Lava grooves: of volcanic origin.
Craters: 10 to 100 kilometres in size.
Cracks: formed by the cooling and shrinking of lava fields.
Mountains & Ring Mountains
mostly run circularly around craters.
are formed by meteorite impacts.
The back side of the moon
We can't see the far side of the moon from Earth. But through a space probe, we know that it looks very different from the front side.
The dark areas are missing.
The moon's crust is twice as thick.
The colouration is more uniform.
There are many more craters.
The craters are more evenly distributed.
The lunar eclipse
A lunar eclipse occurs when the Sun, Earth and Moon are aligned and the Earth's shadow creeps across the Moon.
The following illustration shows you roughly what this looks like:
The formation of a lunar eclipse
A lunar eclipse only occurs at night. The moon must be completely visible from Earth beforehand. So there must be a full moon. The moon, the sun and also the earth are in a line at this time.
The total lunar eclipse
occurs only when the moon is completely immersed in the Earth's shadow.
is also called a "blood moon" because the moon appears red. The reason: the Earth's atmosphere slightly refracts the reddish parts of the sun's rays and throws them onto the moon.
The partial lunar eclipse
A lunar eclipse only occurs at night. The moon must be completely visible from Earth beforehand. So there must be a full moon. The moon, the sun and also the earth are in a line at this time.
Requirements for a lunar eclipse
The Moon and also the Sun each have their own orbits as seen from Earth. The two orbits do not run straight side by side, but have a slight inclination to each other. Therefore, the Moon does not always pass through the Earth's shadow, but moves under it or over it. The intersections of the two orbits are called lunar nodes. A lunar eclipse is only possible when the moon is approaching a lunar node and the sun is right at the same time.
The Moon's influences on the Earth
The Earth and the Moon strongly influence each other. For example, our Earth rotates evenly because of the Moon, because the Earth's axis is stabilised by this natural satellite. If this were not so, we would each have half a year of summer and half a year of winter. But the moon influences even more than the seasons with us on earth.
The tides
I'm sure you're familiar with the terms high tide and low tide. The moon plays an important role in these natural phenomena of our oceans
The moon and the earth revolve around a common centre of gravity, which lies inside the earth. This creates centrifugal forces that move the water - just as, for example, the seats on a chain merry-go-round are pushed outwards. In addition to these centrifugal forces, the gravitational force of the moon also influences the oceans. It is greater than the centrifugal force on the side of the Earth facing the moon. The result: the water there is pulled towards the moon and a flood mountain is formed. On the other side of the globe, on the other hand, the centrifugal force is greater than the gravitational force of the moon. This pushes the water in the opposite direction. A second flood mountain is formed. And because the earth rotates on its own axis once a day, there are two low tides and two high tides every day.
At certain times, the sun also comes into play. When the sun, the moon and the earth are at certain angles to each other, a spring tide or a neap tide occurs. In a spring tide, the gravitational forces of the sun increase the attraction of the moon, so that a particularly high tide forms. The neap tide, on the other hand, occurs when the moon is at a 90° angle to the sun. In this case, the tidal peak is not particularly pronounced.