The Earth is 18 Galactic Years Old

How old is the Earth? This question preoccupied first philosophers, then scientists, for many centuries. Today, we know that the age of the Earth is approximately 4.54 billion years, with an error range of about 50 million years (4.54 × 109years ± 1%). This number is based on evidence from radiometric dating of the oldest-known […]

A new star in heavens: how Crab Nebula was born

In 1054 A.D, a new, very bright star has appeared in Earth’s sky, in the constellation Taurus. Chinese, Japanese, Korean, and Arab astronomers observed the event and noted: “a new bright star emerged in the heavens”. The star was so bright: for nearly three weeks, it was visible even during the daytime, under the hot, […]

Leaving Solar System at the Speed Of Light

Our Solar system is big, and vast, despite it is really small compared to our galaxy, not to mention the complete universe. To put this into a perspective, you can think of yourself as a photon emitted by the Sun. It takes about 8 minutes to reach the Earth after a photon has been emitted […]

Two stars may collide and light up the night sky in 2022

Two stars may collide into a stunning “red nova” in 2022 (or a few months earlier, most probably between September 2021 and September 2022), and for a few weeks become one of the brightest objects in Earth’s night sky, scientists predict. When two stars merge, they increase in brightness 10 thousandfold.

If Andromeda Galaxy were brighter, this is what we’d see

Andromeda Galaxy is the farthest object in the sky that we can see with the naked eye. But if you don’t know where to look, you won’t notice it. If it was much brighter, its appearance in the sky would be sensational. The moon is a good reference for what we’d see if our galaxy’s […]

The Size Of Earth Compared to Other Planets and Stars (and the Universe)

Have you ever wondered how big is the Earth compared to other planets? Or other stars? Or even the Universe itself? When it comes to big numbers, very big numbers, the human brain is weak. In fact, our brains cannot deal with really large numbers. That’s why when the subject is Earth, planets, Solar System, […]

Proxima Centauri b: Did We Find Earth’s Cousin?

On August 24, 2016, a group of scientists led by Dr. Guillem Anglada-Escude at the Queen Mary University of London, announced the discovery of a terrestrial exoplanet orbiting the red dwarf Proxima Centauri, the nearest known star to the Sun. Proxima Centauri is a Latin idiom, meaning “nearest (star) of Centaurus” (see notes 1). The new […]

Earth: a fast-moving Spacecraft

In fact, we’re all living in a fast-moving spacecraft named Earth. Our planet is moving around our sun in an elliptical (an ellipse which is very close to a circle) orbit. The Sun is (our solar system, the Sun, Earth and all the other planets and objects) whirls around the center of our galaxy, the […]