The JPL HORIZONS on-line solar system data and ephemeris computation service provides access to key solar system data and flexible production of highly accurate ephemerides for solar system objects ( 381106 asteroids, 2435 comets, 168 planetary satellites, 9 planets, the Sun, L1, L2, select spacecraft, and system barycenters ). HORIZONS is provided by the Solar System Dynamics Group of the Jet Propulsion Laboratory.
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Planetary exploration missions are conducted by some of the most sophisticated robots ever built. Through them we extend our senses to the farthest reaches of the Solar System and into remote and hostile environments, where the secrets of our origins and destiny lie hidden.
When the Space Age began more than 50 years ago, explorers were eager to visit the planets of the solar system. As the years have passed, however, astronomers have realized that the moons of the solar system may be even more interesting.
Many of these moons are ‘water worlds’ – and planetary scientists, like golden retrievers, always follow the water.
“413 million miles” sounds like a looong way. Something you can see in March might change your mind.
Over 980 million miles or about 1.6 billion kilometers from home, NASA’s Cassini spacecraft hurtles through the starry expanse of space. From its vantage point orbiting Saturn, Earth is nothing more than a miniscule pinprick of light not unlike the stars framing the gorgeous ringed planet.
Cassini has been orbiting Saturn since 2004, and it has made dozens of flybys of Saturn’s intriguing moons. Its next close encounter with Enceladus on October 28, 2015 promises potentially exciting results.
Winter is approaching. The early, wakeful sunbeams of summer are a fading memory as October mornings grow dark and cold. Frankly, waking up isn't as easy as it used to be.....
Except this week.
In the days ahead, if you find yourself yawning over your morning coffee before sunrise, longing for repose, just take a look out the window. Three bright planets are converging in the eastern sky--and the view is an eye opener.
Moonlight is ethereal, enchanting, romantic. For many sky watchers, nothing beats the luminous beauty of a full Moon.
It’s great …. except during a meteor shower. When Earth passes through a stream of comet dust, all that romantic moonlight turns into a nuisance, overwhelming the fainter display of shooting stars.
Now for the good news: The 2015 Perseid meteor shower is here, and the Moon will be dark when it peaks.
When someone says "Once in a Blue Moon," you know what they mean: Rare, seldom, even absurd.
This year it means "the end of July."
For the second time this month, the Moon is about to become full. There was one full Moon on July 2nd, and now a second is coming on July 31st. According to modern folklore, whenever there are two full Moons in a calendar month, the second one is "blue."