A solar eclipse is when the Moon comes directly between the Sun and the Earth, in a straight line. This only happens at the time...
Historically, the evening star is not actually a star but the planet Venus. Shepherds, who rose very early or were active late at night, used...
Shooting stars are not really stars. They are small rocky or dusty pieces, remnants of comets or sometimes asteroids, called meteoroids. They wander in space...
The sky is blue thanks to Rayleigh scattering, a physical phenomenon that relates to how sunlight travels through the air. Sunlight contains all visible colors, but not...
The Earth rotates on an axis that is not straight like a perfectly vertical top, but slightly tilted at about 23.5 degrees. It is because...
A black hole typically appears when a massive star reaches the end of its life. At this stage, there is no more nuclear fuel to...
The celestial bodies were observed very closely because they clearly dictated the daily life in the ancient Mediterranean. The Sun indicated when to start and...
Stars are not always perfectly uniform: they often have darker areas called starspots, similar to the sunspots on the Sun. When the star rotates, these...
Some stars are simply not stable: their internal layers contract and expand periodically, much like a beating heart. This stellar "breathing" is related to imbalances...
Around 240 BC, a Greek scholar named Eratosthenes managed to measure the circumference of the Earth using just a stick planted in the ground, a...
