THE TWINKLE TEST

If you're looking for planets is the night sky, remember to use the "twinkle test." Look for objects that don't twinkle. Stars and planets look different because of the difference in their distance from Earth. Stars are a lot farther away than planets. Even when you're looking through a powerful telescope, stars look like pinpoints. Planets, on the other hand, look like small disks of light. The light of both stars and planets travel through the same amount of the Earth's atmosphere to reach you, but when the light from the pinpoint of a star comes down to you, the atmosphere causes the light to shimmer and dance. Light from a planet is also disturbed by Earth's atmosphere, but the different disturbances from the wider beam of light of a planet's disk usually have little visible effect. If the air is turbulent enough, even a planet will be seen to twinkle

THE MOON

The moon orbits the Earth at a distance of roughly 384,000 miles. It takes the moon about 27.3 days to go around the Earth, but because the Earth is spinning around the sun, it actually takes 29.5 days for the moon to completely go through the cycle of moon "phases" that we see on earth. People often think that the moon's "phases" are caused somehow by the Earth's shadow, but this is not correct at all. The truth is that the moon's surface is half lighted by the sun at any given time. The angle that we are viewing the moon at in relationship to the location of the sun results in us seeing different fractions of the moon's illuminated surface. As the moon rotates around the Earth, we get to see the different "phases." Because the moon completes this cycle every 29.5 days, it is possible to see two "full moons" in the same month. When this happens, which is about everty 2 years, it is called a "blue moon," which is where the phrase "once in a blue moon" comes from.

MERCURY

Mercury is the closest planet to the sun. Mercury rotates so slowly that a day on Mercury is 176 Earth days long. Mercury can get as cold as -279 degrees, and as hot as 800 degrees. Because it is so close to the sun, Mercury can only be seen near sunrise or sunset, and is usually hidden by the glare of the sun. Once every 4 months or so, there is a period when Mercury is furthest from the sun and can be seen.

VENUS

Venus is the second-closest planet to the sun. It has thick clouds containing sulfuric acid, which reflect the sun's light very well, making Venus shine brighter in the sky than any other star or planet. Because it is close to the sun, Venus can only be seen near sunrise or sunset, and is often called the "morning star" or "evening star," because it is often the only visible object in the sky at twilight.

EARTH
The Earth is very easy to see. Just look down. Unlike the other planets, the Earth is almost always easier to see during the day.

MARS
When stargazing, Mars has a lot in common with Venus. It is a close neighbor and is very bright and easily spotted in the night sky. Because of it's movement around the sun, Mars goes from bright to dim back to bright every two years. Depending on conditions in the Earth's atmosphere, Mars usually appears orange, slightly red, or sometimes yellowish.

JUPITER
Jupiter is the largest planet in our solar system. It is not as bright as Venus or Mars, but is still easy to spot. Jupiter has several moons that can usually be spotted with binoculars or a telescope. Some people with extremely good vision can see up to 4 of Jupiter's moons.

SATURN
Saturn is the second-largest planet in our solar system. It is not as bright as Venus or Mars, but is still easy to spot. You will need a small telescope to see the rings of Saturn.

URANUS
Uranus is bright enough to be seen with the naked eye, but appears as a speck of light that can be very difficult to distinguish from nearby stars.

NEPTUNE
Neptune is too dim to be seen with the naked eye.

PLUTO AND CHARON

The furthest known planet from the sun is Pluto. Pluto's moon, Charon, is about half the size of Pluto. The image that you see was taken by the Hubble Space Telescope, and is the clearest image that we have of Pluto and Charon. With this fact in mind, you can simply forget about ever trying to see Pluto in the night sky, even with an average telescope. If you happen to have a telescope that is much better than the Hubble, please send us your pictures!

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