Where Does Outer Space Begin?

Outer space is the expanse that exists beyond Earth's atmosphere but a clear boundary between the two is impossible to define because the density of atmosphere gradually decreases as altitude increases. However, the Kármán line at 100 km above sea level is generally used to mark the beginning of outer space

Do Aircraft Contrails Affect Global Warming?

Following the terrorist attack on the World Trade Centre in September 2001, commercial flights were grounded across the United States for three days and three nights. This absence of aircraft contrails provided an unprecedented opportunity to study their contribution to global warming. It has been argued that contrails reflect heat back

What Is The Ninth Planet In Our Solar System?

Until its reclassification as a dwarf planet in 2006, Pluto was considered to be the ninth planet. However, it is now believed that there really is a ninth planet beyond the Kuiper belt - the cold scattered disc region towards the outer edge of the Solar System. First proposed in 2015,

What Is The Loudest Sound Ever Recorded?

On 27th August 1883, the Indonesian volcanic island of Krakatoa erupted with such devastating force that it tore the island apart, ruptured the eardrums of sailors 40 miles away and could even be heard 3,000 miles away in Mauritius. The pressure wave from the fourth and final explosion generated 310 decibels

Who Drew The First Map Of The World?

Over two thousand years ago in Ancient Greece, mathematician and astronomer Eratosthenes of Cyrene (276 BC – 195 BC) became the father of modern geography and coined many terms that are still in use today. He is best known for calculating the circumference of the Earth by measuring the length of