In this page I will collect a series of fun facts and anecdotes about space, for everybody - especially those who are not experts in this field - to enjoy. If you find some of these anecdotes particularly interesting and you wish to learn more, do not hesitate to contact me.
Did you know that planets don't move on perfect ellipses? Their perihelion, the closest point to the Sun, is in fact not a fixed point in space: after every orbit it moves a little. Newton computed such displacement but the numerical value did not match the actual observed one. This was particularly evident in Mercury's case: the difference between the theoretical value and the observed one was 43 arcseconds/century. Not until Einstein came up with the General Relativity Theory (1915), was such discrepancy solved. The new gravitation theory predicted a new effect which accounted for the mysterious difference in the precession of the perihelion which Newton already came across with. This was the first test proving the correctness of General Relativity.
You probably are aware that Mars has two natural satellites, Phobos and Deimos. What you probably are missing is that Phobos is doomed! Since the latter rotates faster around Mars than Mars around its own axis, the tidal friction makes the distance between the two bodies slowly, but inesorably, decrease. Eventually, the tidal forces acting on Phobos will destroy it. Unfortunately none of us will live long enough to witness this exceptional event in our Solar System.
We Italians are perfectly aware that our culinary tradition is worldwide appreciated, looked up to and imitated (with both good and poor results, tbh). What we did not know is that giants planets are pasta lovers, too! Take a look in the link below at some amazing pictures of what is possibly the weirdest and funniest celestial body known to date: Saturn's moon Pan. The tiny satellite was photographed in early March 2017 by the Cassini spacecraft, which has been studying the second-biggest planet of our beloved Solar System for more than a decade. The orbiter revealed that Pan has the shape of a... raviolo (singular form of 'ravioli')! Are you hungry yet?
It has been almost a year since the Juno spacecraft arrived at Jupiter, and despite the fact that only 6 science orbits occurred (the period being about 53 days) great scientific discoveries were made. JunoCam, the camera onboard, took amazing pictures of the planet, including areas never explored before. This is the case of the poles of Jupiter, which revealed an incredibly restless environment. The picture in the link shows Jupiter's south pole, covered in Earth-sized amazing storms. Considering the bad temper of the Greek God, it seems that the name Jupiter suits the giant planet perfectly.
Another space pill on Juno and its discoveries about Jupiter! A few months ago we published the first-ever solution of the asymmetric zonal gravity field of Jupiter and - guess what? - it is not zero! What does this mean in regular human words? Well, to explain this I should first tell you that the gravity field of a planet is intrinsically related to the distribution of its mass. There is an infinite series of coefficients (the spherical harmonics coefficients) which tell us how the elements distibute in the interior of Jupiter, and one of the objective of Juno is to measure a dozen of these coefficients (the largest and most-important ones). Now, some of them tell us how the mass is distributed in the two hemispheres of Jupiter and we indeed discovered that they are not zero, meaning that there is more mass in one hemisphere than in the other. Practically Jupiter is pear-shaped! Amazing, isn't it?
Exactly 30 years ago the Voyager 2 spacecraft took the first ever pictures of planet Neptune, finally giving the furthest planet of our Solar System a face. The story behind its discovery in 1846 shows the incredible power of mathematics. Until that moment, people believed that the Solar System was composed of 7 planets. Uranus, discovered only about 80 years earlier, was closely studied by astronomers, who had been compiling an accurate table of ephemerides (the positions of the planet during its orbit around the Sun). Some dynamicists remarked something strange: the actual position of Uranus did not exactly match the predictions based on the gravitational attraction of the Sun and the other planets. People came up with the strangest ideas. Someone even conjectured that Newton’s law was not valid at such great distances from the Sun. Two mathematicians, Adams and Le Verrier, more reasonably hypothesized that the distortion in the real Uranus orbit was maybe due to the perturbation of another planet. They made independent calculations and predicted where this unknown planet would be. A telescope pointed at those locations and there it was Neptune! If this does not make you want to study maths, nothing will.
Those who have never watched the original Star Wars trilogy, raise your hands. Well, shame on you! By all means you must be familiar with the picture of a giant quasi-spherical spaceship called the "Death Star". What even the biggest fans of SW might have missed though is that the idea for that powerful weapon design came from an actual space object: Saturn's moon Mimas. Because of its small size (only 400 km in diameter - for comparison our Moon is 3500 km), you would not think that Mimas is a threat to Saturn's system. Yet this little moon is responsible for the biggest gap in Saturn's rings, the so-called Cassini Division. Millions of years ago the same particles that constitute the beautiful rings used to populate the now empty Cassini Division ...and then there were none. But how could Mimas, so small in size and far from the rings (we're talkin hundreds of thousand kms here), do that? The reason is that Mimas' distance from Saturn is such that a particle in the Cassini Division would resonate with Mimas. This phenomenon causes great instability, and eventually the particle would be ejected from its location. Find out more about resonances in the link below!