One day on the planet Mercury lasts for 176 Earth days. The big time difference is due to Mercury's length of rotation, which is much slower than Earth's.
To an observer standing on Pluto, the Sun would appear no brighter than Venus appears in our evening sky.
The moon is one million times drier than the Gobi Desert.
One square inch of the sun's surface shines as bright as 300,000 candles.
The Moon weighs 81 billion tons.
One year on Saturn is 29 and a half times longer than ours, but its day is shorter than ours: 11 and a half hours.
Our galaxy has approximately 250 billion stars – and it is estimated by astronomers that there are 100 billion other galaxies in the universe.
Traveling at the speed of 186,000 miles per second, light takes 6 hours to travel from Pluto to Earth.
Triton, a moon of Neptune, is the coldest known place in the solar system. Its surface is 390 degrees Fahrenheit below zero.
The moons of Mars are called Phobos and Deimos after two mythical horses that drew the chariot of Mars, the Roman god of war.
Until the mid-sixteenth century, comets were believed to be not astronomical phenomena, but burning vapors that had arisen from distant swamps and were propelled across the sky by fire and light.
The most ancient report of a solar eclipse is in Chinese records. The eclipse came without warning, according to legend, because the royal astronomers, Hsi and Ho, were too drunk to make the necessary computations. They were executed – the only astronomers known to have been killed for dereliction of duty.
Our galaxy probably contains millions of old neutron stars that have stopped spinning, and so are undetectable.
Uranus is the only planet that rotates on its side.
The most large telescopes in one city in the world are in Tucson, Arizona.
Our solar system lies halfway along the Orion arm, about 24,000 light-years from the galactic center.
Venus has no magnetic field, perhaps because of its slow rotation. It also has no satellites.
The most luminous star is likely Eta Carinae, which has a maximum luminosity of around 5,000,000 times that of the Sun.
Our Sun burns 9 million tons of gas a second. At this rate, it has been estimated it will burn out in another 10 billion years.
Venus is much brighter than any other planet or star. At its brightest, it can cast shadow, and even be seen during the day time.
|© 2006 The Mine of Useless Information