The vastness of the universe is beyond the comprehension of ordinary people. At the same time, it is a universe space composed of multiple orbits coexisting.

The Earth we live on is an ordinary planet orbiting the Sun, and the Sun itself is just a typical star in the Milky Way galaxy. The solar system is part of the Milky Way galaxy.

After clarifying this simple relationship, let's take a look at a set of important and interesting numbers about interstellar space, exploring the relationships and mysteries between interstellar spaces.

Milky Way Galaxy

The center of the Milky Way galaxy is a supermassive black hole. While rotating around its center, the Milky Way also orbits the universe at a speed of 514,000 miles per hour.

Even so, it takes 230 million years for the Milky Way to complete one rotation around the universe, illustrating how vast and boundless the universe is. The time it takes to orbit the universe once is also called a galactic year.

If calculated in galactic years, our Earth has experienced 18 galactic years so far.

Earth and Space Interface

Looking from the Earth, countless stars can be seen on the horizon. If one could drive directly into space, it would only take one hour because the distance between space and the Earth's atmosphere is only 100 kilometers. This line is also called the Kármán line.

The Kármán line is the internationally recognized boundary between outer space and the Earth's atmosphere, located at an altitude of 100 kilometers. It is acknowledged by the International Astronautical Federation, which is responsible for setting and maintaining international aviation and space standards.

Black Hole in the Milky Way

The center of the Milky Way is a massive black hole, with a volume of 4 million times that of our Sun.

It is approximately 28,000 light-years away from us. To put it into perspective, the Milky Way's black hole can hold millions of Earths.

However, black holes are invisible. Their gravity is so strong that even light cannot escape them.

Neptune - Planet of Strong Winds

Neptune is one of the nine planets in the solar system and it's also the windiest planet. Wind speeds on Neptune can reach up to 1,600 miles per hour. It is about 4 light-hours away from the Sun.

Neptune's moon Triton is one of the coldest places in the solar system, with a surface temperature of -391 degrees Fahrenheit.

Unfortunately, Neptune cannot be seen with the eye in the night sky; a telescope is required.

The Moon is Drifting Away

The Moon is our familiar satellite, closely related to us. But in reality, the Moon is gradually drifting away.

In 1969, during the Apollo 11 mission, astronauts placed mirrors on the lunar surface to determine if the distance between the Moon and Earth was constant or changing.

Scientists use laser pulses to measure the distance between Earth and the Moon and have found that the distance increases by 3.8 centimeters per year.

The Sun is an Ordinary Star

The mass of the Sun accounts for 99.8% of the total mass of the solar system. Moreover, the Sun's core has high density and temperature. Nuclear fusion in the Sun's core generates immense energy.

The Sun is just a typical star in the universe. However, even so, it is 1 million times larger than the Earth.