Alfredo’s Top 5 Physics & Astrophysics Stories Of 2015

Alfredo’s Top 5 Physics & Astrophysics Stories Of 2015
1 January 2016

NASA’s discovery of water on Mars

Billions of years ago, Mars looked more welcoming to life than Earth was at the time. We have seen evidence of ancient lakes and river beds, but nowadays water on the surface of Mars exist almost entirely as ice. In 2007, scientists observed some dark lines forming in the summer months on the side of craters, a potential indication of flowing water on Mars. This year, NASA confirmed it. Mars has small streams of flowing brine, water with high concentration of salts, which remain liquid in the frigid summers of the red planet. Liquid water could be an indication of life, but most importantly we know that flowing water continues to shape, to a lesser degree, the surface of Mars.

Spooky action at a distance is real

One of the predictions of quantum mechanics which Einstein bitterly tried to disprove has been proven absolutely correct. Quantum particles can be produced in an entangled state, a special condition that allows the particles in this state to influence each other instantaneously even if they are on the opposite sides of the universe. The experiment proved that entanglement is real, and in particular that there are no other mechanisms (that we are yet to understand) at work. The idea behind this is called “Bell’s Theorem” and it has been described as “the most profound discovery in Science.”

Earth 2.0

In the summer, we have observed the closest Earth-like exoplanet, Kepler 452b. The exoplanet orbits a star very similar to our Sun at approximately the same distance as the Earth does. The object has been described more like a ‘cousin’ of Earth, rather than a twin. It is 5 times heavier than the Earth (leading to double the gravitational pull). Its star is also much older than the Sun, emitting 20% more light than our docile star, which would lead to a runaway greenhouse effect on Kepler 452b similar to the one we see on Venus.

New Particle Discovered at CERN

For the first time, the Large Hadron collider was able to produce the elusive pentaquark, a particle which was first considered to exist in 1964. The particle is formed by 5 quarks, the smallest particle known to us. Quarks tend to form couples or triplets, like for example protons and neutrons. Pentaquarks are really unstable, decaying in a billion trillion trillionth of a second, but that’s enough for scientists to study their properties, which will lead to a better understanding of how even ordinary matter is formed.

Pluto’s ALIVE!

My personal favourite story of the year is probably New Horizons mission to Pluto. It was an incredible achievement: the probe itself travelled for 10 years and arrived at Pluto within 72 seconds of the expected time. What New Horizons saw was unexpected. Pluto is an active world. It has an atmosphere, mountains, canyons, cryovolcanoes, and an active geology. More analysis of the data taken by New Horizon will be published in the next few months and it will continue to expand our knowledge of the king of the Kuiper belt.