Last week scientist announced that the amount of galaxies in the universe had been underestimated by as much as a factor of 20. Major news, but not something that really affects our daily lives. The discovery does however, illustrate the vast scale of our universe. Thankfully, we as humans have developed the brain capacity, the intelligence and the curiosity to help us understand our place within it. Take for example the speed of light. It travels at 300,000 km per second. Pretty much instantaneous for us on earth, but really noticeable in the realm of the galaxies, stars and planets. Light from the moon takes little over a second to reach us, whilst light from the sun takes over 8 minutes. That means that the light from the sun that is hitting your eyeball is over 8 minutes old.
At the end of September, scientists from NASA, using data from the Hubble Space Telescope announced that they had discovered water vapour plumes on Jupiter’s moon, Europa. The plumes extend more than 100 miles into space. The discovery was announced in a hastily arranged press conference amidst excitable rumours that NASA had discovered aliens. No aliens were forthcoming, but the discovery is certainly is good news for planetary scientists looking for extraterrestrial life.
A blast from the past. This article and interview first appeared in Astronomy and Space magazine in June 2007.
The early Solar System was a violent place. One theory states that shortly after Earth’s formation four and a half billion years ago, a body the size of Mars thumped into Earth, blasting off massive amounts of debris. This debris eventually coalesced to form the Moon. After formation, the Moon underwent a period of intensive bombardment by meteorites that scared, fractured and left the Moon covered in craters of all sizes. This period was known as the late heavy bombardment and occurred between 4.1 and 3.8 billion years ago.