What Are the 3 Types of Galaxies?
Hubble galaxy classification assigns a class to galaxies based on their visual appearance. These classes of galaxies are ellipticals, lenticulars and spirals
Outer Space
Milky Way Galaxy: 200 Billion Stars and Our Solar System
Galaxies are just large accumulation of stars. For example, we live in the Milky Way galaxy. It houses about 200 billion stars including Alpha Centauri.
Earth Age: How Old Is the Earth?
By dating meteorites, we find the oldest rocks are 4.5 billion or so years old. Thus, we conclude the same staggering 4,543,000,000 years for Earth’s age.
![7 Red-Hot Planet Mercury Facts [Infographic]](https://earthhow.com/wp-content/uploads/2018/06/Mercury-425x319.png)
7 Red-Hot Planet Mercury Facts [Infographic]
Not only is planet Mercury the closest to the sun, but it has extreme temperatures. Facts about Mercury: Its long comet-like tail, craters and unusual orbit
![Universe Expansion: The Farthest Galaxy from Earth [Infographic]](https://earthhow.com/wp-content/uploads/2018/12/Universe-Expansion-425x319.png)
Universe Expansion: The Farthest Galaxy from Earth [Infographic]
The universe is immeasurable in size. Universe expansion is the theory that galaxies and all matter in space are increasing in distance between each other.
Sun Fusion: How the Sun Heats Up Earth
Fusion reactions power the sun. By fusing hydrogen to helium, the sun releases vast amounts of energy towards Earth. Then, sun fusion reaction heats Earth.
Planet Formation and the Core Accretion Theory
We use the core accretion model to describe planet formation and the creation of our solar system which includes a central star and natural orbiting objects.
Earth Tilt: 23.5 Degrees Axis
Imagine sticking a pencil into the Earth’s poles and twisting your wrist 23.5°. This is the Earth tilt essential in seasonal patterns, climate and life on Earth.
Density of Earth: What is the Earth Made Of?
Earth density steadily increases as you go inwards from the crust to core. If you average density throughout the whole planet, it is about 5.513 g/cm^3.
![10 Planet Venus Facts [Infographic]](https://earthhow.com/wp-content/uploads/2018/08/Venus-425x319.png)
10 Planet Venus Facts [Infographic]
Planet Venus neighbors the Earth. It’s the second planet closest the sun. Other facts include its counterclockwise rotation and how it rains sulfuric acid.
Why Does the Earth Hum?
Seismometers always record periodic noise. Once mysterious in nature, we attribute Earth hum to ocean waves crashing into continents, vibrating like a bell.
![5 Facts of Ice-Cold Planet Uranus [Infographic]](https://earthhow.com/wp-content/uploads/2018/06/Uranus-425x319.png)
5 Facts of Ice-Cold Planet Uranus [Infographic]
Planet Uranus is the coldest and has the 3rd largest radius for any planet in the solar system. It’s tilted at more 90°, it has faint rings and has 27 moons.
Shape of the Earth: The Oblate Spheroid
Earth is not a perfect sphere. In fact, it’s in the shape of an oblate spheroid. Earth shape bulges at the equator and flattens at the north and south pole.
Chandler Wobble: Why the Earth Wobbles Like a Toy Top
Earth spins on its axis of rotation. But it doesn’t spin perfectly. Like a toy top, it wobbles when it spins. This displacement is the Chandler Wobble.
What is Earth’s Escape Velocity?
The escape velocity of Earth (11.186 km/s) is the speed at which a free object must travel to escape into space from the planet’s gravitational pull.