Even at oppositon, Mars won't look this big from Earth. This view of the red planet was made from images captured by spacecraft. Click on image for full size (54K JPEG) Image courtesy NASA/JPL.

The planet Mars will be much closer to Earth than it normally is at 0319 Universal Time on October 30, 2005. Earth and Mars will pass within 69 million km (43 million miles) of each other, and Mars will be very bright in the sky. Mars won't look any larger than normal if you view it with your naked eye (that is, without a telescope or binoculars)... it will look like a very bright, red star.

Planets that are closer to the Sun move faster than planets further away. Since Earth is closer to the Sun than Mars is, Earth passes Mars about once every 26 months. The situation is similar to a fast race car passing a slower car on the "inside lane" of an oval racetrack. When Earth passes Mars, astronomers call the event an "opposition". During an opposition, the Sun, Earth, and Mars form a straight line, with Mars on the opposite side as the Sun as viewed from Earth. Not all oppositions are created equal. Since Mars's orbit is elliptical or oval-shaped (unlike Earth's, which is nearly a perfect circle), some oppositions bring the two planets closer together than others. "Close" oppositions occur when Earth passes Mars at the point in Mars's orbit when Mars is closest to the Sun.

Check out this interactive animation of the orbits of Earth and Mars to see where the planets are right now.

The closest Mars opposition in thousands of years happened on August 27, 2003, when the planets passed within 56 million km (35 million miles) of each other. Really "close" oppositions generally happen once every 15 or 17 years. The next especially close Mars opposition will be in July of 2018. If you missed the 2003 opposition, you won't have to wait thousands of years for an even better view. Mars will have an opposition even closer than the 2003 event on August 28, 2287!

Even at oppositon, Mars won't look this big from Earth. This picture was taken by a spacecraft. Click on image for full size (54K JPEG) Image courtesy NASA/JPL.

The planet Mars is closer to Earth than normal right now. On October 30, 2005, the two planets will be very close to each other. They will be about 69 million km (43 million miles) apart. Mars will look like a very bright red star in the sky then.

Earth moves around the Sun more quickly than Mars. Every 26 months, Earth "laps" Mars on "the inside lane". When Earth passes Mars, astronomers call the event an "opposition". During an opposition, the Sun, Earth, and Mars form a straight line with Earth in the middle. Viewed from Earth, Mars is on the opposite side of the sky from the Sun. Opposition is the time in each 26-month cycle when Mars and Earth are closest together. Mars was even closer to Earth in August 2003.

Check out this movie of the orbits of Earth and Mars to see where the planets are right now.

The distance between Earth and Mars is not always the same at opposition. The orbit of Mars is an oval, not a circle. Earth can be closer or further from Mars at opposition, depending on where in Mars's orbit the Red Planet is when Earth passes it. This time around the two planets get really, really close together! Since Mars will be so close during this opposition, it will be very bright in the sky and will look larger than usual through a telescope.

Even at oppositon, Mars won't look this big from Earth. This picture was taken by a spacecraft. Click on image for full size (54K JPEG) Image courtesy NASA/JPL.

Sometimes Earth gets pretty close to the planet Mars. Mars and Earth will be close to each other on October 30, 2005. Mars will look like a bright red star. Mars will be about 69 million km (43 million miles) from Earth. Even when planets are "close" to each other, they are still a long way apart!

Earth and Mars get pretty close together once every 26 months. When the two planets get close, astronomers call the event an "opposition". That is because the Sun and Mars are on opposite sides of the sky during an opposition. The orbit of Mars is not quite a circle. It is shaped more like an oval. Sometimes Earth gets closer to Mars than normal when Mars is at just the right place in its orbit. When it does, we have a really "close" opposition. Mars was really, really close to Earth in August 2003. It will be pretty close to Earth in October 2005.

Check out this movie of the orbits of Earth and Mars to see where the planets are right now.

When Earth is close to Mars, Mars looks like a very bright star in the sky. If you get a chance to see Mars through a telescope, it will look a bit bigger than usual. If you want a really close-up view of Mars, though, the best way to get that is to look at pictures from spacecraft orbiting Mars!