"Men might as well project a voyage to the Moon as attempt to employ steam navigation against the stormy North Atlantic Ocean." — Dr. Dionysius Lardner, 1838
In 435 B.C., the Greek philosopher Anaxagoras suggested that the sun was not just a small glowing circle of light. He maintained that it was a glowing rock larger than the Peloponnesus. For maintaining such beliefs (and, to be fair, for political reasons too), he was exiled from Athens. [ Ancient Greek Science and Philosophy | Solar System ] (source)
The Greek scientist Aristarchus believed that the motions of the heavenly bodies could easily be understood if it were assumed that all of the planets, including Earth, revolved around the sun and that the stars must be infinitely far away because they seemed motionless. Copernicus knew of Aristarchus' views and mentioned them in a passage in De Revolutionibus Orbium Coelestium that he later eliminated, as though not wishing to compromise his own originality. [ Ancient Greek Science and Philosophy | Solar System | Geniuses ]
The first Greek astronomer to suggest the sun was the centre of the solar system was Aristarchus of Samos, around 290 B.C. No one took him seriously, and his writings no longer exist. We know of him today only because Archimedes (whose writings do exist) referred to Aristarchus as holding this apparently nonsensical notion. [ Firsts | Ancient Greek Science and Philosophy | Solar System ] (source)
To the nearest ten-thousandth of a mile, light travels at 186,282.3959 miles per second. At that rate, it takes slightly more than eight minutes to get to Earth from the sun. However, it takes light hundreds of years to travel from the sun's centre to its surface. The light must take a very indirect path to the surface due to the large number of collisions with particles within the sun. [ Physics | Solar System ]
Gervasius, a monk at Canterbury some 800 years ago, reported seeing a great burst of fire on the face of the moon. He wondered if this was an omen of some great event on earth, but as time passed and nothing happened, scholars and others assumed that he must have been mistaken. Recently, however, astronomer Jack B. Hartung of New York University has vindicated the mediaeval monk by saying that what he was was the impact of a huge meteor causing an explosion and fire on the surface. The crash created the huge crater known was the Giordano Bruno.
The moons of all planets are named after Greek gods, except for the moons of Uranus, which are named after Shakespearean characters. [ Solar System | Books and Literature ]
The planet Uranus lies on its "side", and there is no adequate explanation as to why. The extreme axial tip of Uranus is 98° as it revolves around the sun. The axis of Earth is tipped at 23.5°, Mars at 24°, and Jupiter at only 3°.
The planet Neptune has not made a complete revolution around the sun since it was discovered in 1846. With an orbital period of 155 years, it will have completed an orbit in 2011.
The moon is just large enough to cover the sun completely, at times, as seen from Earth. It is a sheer astronomical accident, and what makes a total eclipse possible. It is also small enough so that during the sun's obscuration the corona, especially the brighter parts near the body of the sun, is completely visible. There is no astronomical reason why the sun and moon "fit" so well. The Earth, among all the planets in the solar system, is the only one blessed in this fashion.
According to the laws of gravity, the moon technically does not orbit the Earth. The two bodies actually both orbit around their common centre of gravity, which is located 1,000 miles beneath the surface of the Earth and is on a straight line between the centres of the Earth and moon. The centre of the Earth makes a small circle around that centre of gravity every 27 1/3 days. [ Solar System | Physics ]
The first woman in space was a Soviet, Valentina Tereshkova, in 1963. No female Americans went into space until twenty years later, when Sally Ride did in 1983.
The last person on the moon was Eugene Cernan. He and fellow explorer Harrison Schmidt left the moon at 5:40 A.M. GMT, December 13th, 1972. No humans have visited the moon since then. [ Solar System | Lasts | Technology ]
Venus, not Earth, is the best-mapped planet in the solar system, with 98% of its surface mapped. On the other hand, large portions of the Earth's ocean floor have not been mapped.
A perpetual motion machine would violate the laws of thermodynamics. No-one has ever built one, and no-one ever will.
Unlike Earth, Saturn is made mostly of hydrogen and helium, so its density is only 0.13 that of Earth.. While it has heavier materials in the core, it is the only planet in the Solar System that is less dense than water. (source)
Saturn's moon Iapetus (eye-AP-eh-tuss) is a very curious moon -- it seems to have a split personality! One hemisphere is covered with material darker than black velvet, while the other side is covered with material brighter than snow. (source)
On January 11, 1610, Galileo Galilei discovered Jupiter's moon Ganymede. Ganymede is the largest satellite in the solar system with a diameter of 5,268 km (3270 miles). It is larger than Mercury and Pluto and 3/4 the size of Mars. (source)
Saturn's moon Mimas has an enormous crater named Herschel that is 130 kilometers (80 miles) wide, one-third the diameter of Mimas. The impact that caused the crater probably came close to shattering Mimas. (source)
Titan is the largest of Saturn's moons. It is the second largest moon in the solar system. In fact, it is larger than both Mercury and Pluto. Scientists are particularly interested in Titan because it's one of the few known moons with its own dense atmosphere. Titan's atmosphere is also thought to be very similar to what Earth's atmosphere was a long time ago. By learning about Titan, we'll learn about our own planet. (source)
The space between Mars and Jupiter is filled with a population of irregularly shaped chunks of rock and metal called asteroids. Scientists believe the asteroids are pieces of a planet that never formed. (source)
Pluto was discovered on February 18, 1930 by Clyde Tombaugh at the Lowell Observatory in Flagstaff, Arizona. (source)
The three objects in the solar system known to have nitrogen-dominated atmospheres are Earth, Saturn's moon Titan, and Neptune's moon Triton. (source)
Did you know that 842 lbs. (382 kg) of rocks were brought back from the moon during the Apollo missions? (source)
Pan, one of Saturn's smallest moons, orbits within Saturn's A-Ring and helps clear out an area between the rings called the Encke Gap. Scientists believe that if Pan didn't exist, neither would the Encke Gap. (source)
The small and rocky planet Mercury is the closest planet to the Sun. Temperatures on Mercury's surface can reach a scorching 467 degrees Celsius, but because the planet has hardly any atmosphere to keep it warm, nighttime temperatures can drop to a frigid -183 degrees Celsius. (source)
Saturn's moon Hyperion (high-PEER-ee-on) is shaped sort of like a hamburger patty and rotates chaotically because of the gravitational influence of nearby Titan, another of Saturn's many moons. (source)