NASA’s recent Dart mission to deflect an asteroid’s path, serves to illustrate just how precarious Earth’s existence is. We are at the mercy of what the Universe throws at us. Our atmosphere and magnetic field serve us well in protecting us from cosmic rays, eruptions of particles and energy from the Sun, and the small meteors that continually bombard us. The presence of large planets like Jupiter and Saturn in our Solar System act as protective big brothers, sweeping up any wayward asteroids that happen to pass by on the way to Earth.
The universe is a strange and wonderful place, primarily empty space with a smattering of galaxies scattered about. Each galaxy has hundreds of billions of stars and the universe itself is so vast that it has one hundred billion galaxies. The enormity and scale is impossible to get our heads around and it takes rare geniuses like Einstein, Newton and even Hawking who have the uncanny ability to visualise, scrutinise and probe the depths and workings of the universe. Even the nearest star to us is 4 light years away, which in layman’s terms is a staggering 40 trillion kilometers, that is 40 with 12 zeros after it. The Voyager 1 spacecraft, launched in 1977 to study the solar system travels at 62,000 km/h. At this speed, It would take 73,000 years to get to the nearest star and a cool 640 million years to get to the centre of our galaxy!
Launched in 1997, the Cassini mission to Saturn sent it’s final images back to earth last week before plunging into the planet in a planned manoeuvre. It spent 13 years in orbit around the ringed planet, carried out some spectacular science and beamed some great images back to earth.
Severe brain trauma from accident or injury can lead to patients ending up in a persistent vegetative state in hospital. The lights may be on, but often it seems that no one is home.
The past week has seen my phone emit a flurry of chirps, beeps and flashing LEDs. They have been alerts from Twitter or from an Aurora Watch UK app. Most of the them have been yellow alerts with the occasional amber alert, letting me know that there is a slim possibility of seeing the aurora or Northern Lights.