The planet Jupiter is approaching Earth for the closest encounter of the two planets since 1963. We will be able to witness a dazzling celestial phenomenon when Jupiter will be as much as 75 million kilometers closer to Earth than in any previous encounter. Jupiter will pass Earth late Monday into early Tuesday at 368 miles from the Earth. At midnight, it will be directly overhead. That’s because Earth will be passing between Jupiter and the sun lasting into the early hours of Tuesday.
The Jupiter-Earth-Sun alignment is called the night of opposition since Jupiter will be opposite the Sun, rising at sunset and soaring overhead at midnight. Only the moon will appear brighter in the midnight sky. This will not happen again until 2022. Even a small telescope pointed at Jupiter at this time will reveal the planet’s moons, cloud belts and swirling storms.
Earth-Jupiter encounters happen every 13 months when the Earth laps Jupiter in their race around the sun. But because Earth and Jupiter do not orbit the sun in perfect circles, they are not always the same distance apart when Earth passes by. The Earth is about 93 million miles from the Sun while Jupiter is about 483.78 million miles from the Sun.
If Monday night is cloudy in your area, the phenomenon can still be observed since Jupiter will remain close for many weeks. Also, Jupiter will be visible setting in the west just before sunrise, for those who rise early.
Jupiter is the largest planet in our Solar System and the fifth planet from the Sun. It already appears as a bright star in the sky – three times brighter than Sirius which is the brightest star in the sky. Right now, only the moon is brighter than Jupiter in the night sky.
It is an interesting coincidence that Uranus, the third largest planet, will also make a close approach on the same night, although Uranus will actually be 1.7 billion miles from Earth at that time. It will be seen less than one degree away from Jupiter but it will be much easier to see through a telescope than with the naked eye. Uranus is almost three times smaller and five times farther away than Jupiter, barely visible to the naked eye. This smaller planet is also at opposition tonight. Scientists have called this a once-in-a-lifetime event.
Look at the sky on the night of closest approach, September 20-21, 2010. It will be even better if you have a telescope. You will not have this opportunity again until the year 2022.