Planetoids : Asteroids

An asteroid is a minor planet of the inner Solar System. Historically, these terms have been applied to any astronomical object orbiting the Sun that did not resolve into a disc in a telescope and was not observed to have characteristics of an active comet such as a tail.

As minor planets in the outer Solar System were discovered that were found to have volatile- rich surfaces similar to comets, these came to be distinguished from the objects found in the main asteroid belt.

The term “asteroid” refers to the minor planets of the inner Solar System, including those co- orbital with Jupiter. Larger asteroids are often called “Planetoids”.

Asteroids vary greatly in size from almost 1000km for the largest down to rocks just 1 meter across. The three largest are very much like miniature planets : they are roughly spherical, have at least partly differentiated interiors, and are thought to be surviving protoplanets.

“This planet is 15 million years overdue for an asteroid strike like the one that killed the dinosaurs.” – L Niel Smith

“If the Earth gets hit by an asteroid, it’s game over. It’s control-alt-delete for civilization.” – Bill Nye

The vast majority, however, are much smaller and irregularly shaped; they are thought to be either planetesimals or fragments of larger bodies.

The four largest asteroid-

Ceres – 939km
Vesta – 525km
Pallas – 512km
Hygiea – 434km

International Asteroid Day

Asteroid Day is an annual global event which is held on the anniversary of the Siberian Tunguska event that took place on June 30, 1908, the most harmful known asteroid- related event on Earth in recent history.

Asteroid Day aims to raise awareness about asteroids and what can be done to protect the Earth, it’s families, communities and future generations.

“The idea is to raise awareness of, not only the dangers of asteroids but also the fact that we have solutions in hand to find dangerous asteroids and do something about it.” – Tom Jones

“Sooner or later disasters such as an asteroid collision or a nuclear war could wipe us all out, but once we spread out into space and establish independent colonies, our future should be safe”. – Stephen Hawking

https://www.jagranjosh.com/general-knowledge/world-asteroid-day-quotes-1593472957-1

https://www.azquotes.com/quotes/topics/asteroids.html