This is where we live and where our nearest neighbors are. Here is a tour of the planets and their moons, asteroids and comets, and far out to Pluto and Charon, the Kuiper Belt and the Oort Cloud.
10 Amazing Facts about the Solar System
Our Solar System is pretty amazing. There's a planet that orbits lying down and a surprising number with rings. The Sun is losing mass at the rate of 300 million tons a minute, but it's nothing to worry about. And how did bits of Vesta end up on Earth?
ABC of Astronomy – E Is for Ecliptic
Star maps show you where the ecliptic is. That's because it's where you find the planets and the zodiac constellations. But what is the ecliptic plane on which the planets orbit? What shape are their orbits, and what do we mean by an eccentric orbit?
Comets Asteroids Meteors
Articles about these leftovers from forming the larger Solar System bodies out of a cloud of gas and dust. They attract our attention if they come too near Earth.
Copernicus - the Revolution
In the 16th century everyone knew that Earth was the center of the cosmos. But this made it impossible to predict the motions of heavenly bodies, even if they moved in elaborate circles within circles. Copernicus turned the idea on its head and put the Sun at the center. A revolution had begun!
Earth & Moon
Articles about our home - and our close companion, object of awe, subject of poetry and the only other world on which humans have walked.
Father Hell - Astronomer
The Moon´s Hell crater sounds like the last place a space tourist would ever want to visit. But it´s named for 18th century astronomer Father Maximilian Hell, director of the Vienna Observatory. He observed the 1769 Venus transit from Norway´s far north, surviving the cold by adopting Sami dress.
Galileo´s Daughter - book review
Most people think of Galileo as the man who is a symbol of the heroic voice of truth against a powerful reactionary Church. However this mythic Galileo is not the one Dava Sobel´s book, "Galileo´s Daughter", reveals through his faith, his work and his daughter´s love.
Outer Solar System
The Trans-Neptunian objects (TNOs) are here. The region includes the Kuiper Belt, scattered disk and the Oort Cloud. The best known objects are Pluto and its moons, but there are comets too.
Phantom Planets and Moons
Moons of Venus and Mercury? An unknown planet nearer the Sun than Mercury? Astronomers can misinterpret what they see, too. Happily, other observers, better instruments and new theoretical understandings can put it right. Here are some phantom objects that many astronomers once thought existed.
Planets & Moons
Earth´s companion planets and their moons
Solar System - Our Neighborhood
Come tour the Solar System. It's our neighborhood, the star system in which we live. The Sun's gravity holds it all together - planets, dwarf planets, moons, asteroids, comets, Kuiper Belt objects. See what lies between the Sun and the farthest edge of the Oort Cloud.
Solar System - Tour for Kids
Take a quick tour of the Solar System, the star system where we live. It's our neighborhood of the Milky Way. Find out what lies between the Sun and the edge of the Oort Cloud.
Solar System Discoveries – Quiz
Since prehistoric times people have known the Sun, the Moon and five planets. The rest of the Solar System had to await discovery by people with telescopes. How many of the discoverers can you identify?
The heart of the Solar System and what sustains life, the Sun is our star.
The Transit of Venus - book review
In the north of England in the early 17th century, there was an amazing circle of astronomers. They were well ahead of their time and included the first two people ever to observe a transit of Venus. What ended this brief flowering? Peter Aughton tells the story.
Top Astronomy Stories 2012
What were the big astronomy stories of the year 2012? Here is my choice of the top ten plus a non-story. What do you think?
Transit of Venus - Captain Cook 1769
How big is the Solar System? 18th century astronomers tried to find out by sending expeditions around the world to measure a transit of Venus. One of these was Captain Cook's voyage to Tahiti. He went under the auspices of the Royal Society, but he carried secret orders from the British government.
Transit of Venus - Measuring the Solar System
On June 8, 2004 millions of people witnessed an event that no one still alive had ever seen: a transit of Venus. Another occurred in June 2012, but it was the last for over a hundred years. What is a transit of Venus? How did it help to work out out the size of the Solar System?
Voyager 1 – the First Starship
Has Voyager 1 finally left the Solar System? No, that won´t happen for tens of thousands of years. But it has left the bubble that the solar wind makes in space. The spacecraft is in the space between the stars, moving through a plasma made from ancient supernova explosions.
Water Water Everywhere Astronomy Homepage | Editor's Picks Articles | Top Ten Articles | Astronomy Site Map
Earth is a watery planet, the only one in the Solar System with surface oceans. Although there's a lot of water here, there seemed to be little or none elsewhere. Fortunately, space telescopes and space probes have detected what we couldn't find before, and there now seems to be water everywhere.
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