Space
Space refers to the vast, seemingly infinite expanse that exists beyond Earth's atmosphere and between celestial bodies. Here are some key points about space:
The Universe: The universe is the entirety of space and everything that exists within it, including galaxies, stars, planets, and other celestial objects.
Galaxies: Galaxies are massive collections of stars, gas, dust, and dark matter held together by gravity. The Milky Way is the galaxy in which our solar system resides.
Stars: Stars are luminous spheres of plasma held together by their own gravity. They emit light and heat through nuclear fusion, where hydrogen atoms combine to form helium, releasing enormous amounts of energy.
Planets: Planets are celestial bodies that orbit around stars and do not produce their own light. They are typically solid, spherical, and have cleared their orbits of debris. Our solar system has eight planets, including Earth.
Moons: Moons, also called natural satellites, are objects that orbit planets. They can be rocky or icy and come in various sizes. Earth has one moon, but other planets have multiple moons.
Astronomical Units: Astronomers use astronomical units (AU) to measure distances within our solar system. One AU is approximately the average distance between the Earth and the Sun, about 93 million miles or 150 million kilometers.
Exoplanets: Exoplanets are planets that orbit stars outside our solar system. Thousands of exoplanets have been discovered to date, some of which are in the habitable zone, where conditions could potentially support life.
Black Holes: Black holes are regions in space where gravitational forces are so strong that nothing, not even light, can escape their gravitational pull. They form from the remnants of massive stars that have undergone a gravitational collapse.
