The Opposition of Saturn In July 2019

The flagship planetary event of July is here. The opposition of Saturn will take place on July 9, 2019. It is the time we go between the Sun and the Lord of the Rings. Here are three important things to know about this planetary opposition.

1. What Is Opposition?

In celestial mechanics, a planetary opposition occurs when the Earth lies between the Sun and the planet with Earth being on the same side of the planet as shown below.

Opposition of Jupiter

Thus on July 9, Sun, Earth and Saturn will lie along a straight line with Earth at the center. This optimal positioning occurs when Saturn is almost directly opposite the Sun in the sky. Since the Sun reaches its greatest distance below the horizon at midnight, the point opposite to it is highest in the sky at the same time. At around the same time that Saturn passes opposition, it also makes its closest approach to the Earth – termed its perigee – making it appear at its brightest and largest. However, Saturn's orbit lies far out in the solar system, at 9.5 AU and hence the angular size of Saturn doesn't vary over the course of conjunction and opposition.

Also Read: 10 Amazing Facts About NASA's Most Successful Mission, The Cassini Huygens

2. How Close Will Be Saturn?

Saturn as captured by the Cassini Spacecraft

At the opposition, Saturn will be at a distance of about 1.35 billion Km (9.06 AU). This is about 66 million Km closer than the average distance from Earth. Even at its closest approach to the Earth, however, it is not possible to distinguish it as more than a star-like point of light with the naked eye, though a good pair of binoculars is sufficient to reveal its rings with accompanying system of moons.

Also Read: 10 Most Stunning Images of Saturn Clicked By Cassini Space Probe

3. How To Watch Saturn And Its Rings

Opposition marks the middle of the best time of year to see a planet. The Lord of the Rings will be visible shortly after the sunset rising around 20:04. For observers in the northern hemisphere, Saturn will rise in south-east direction in the constellation of Sagittarius. For observers in India and around, It will reach its highest point in the sky at 00:28, 39° above the southern horizon. It will become inaccessible around 04:44 when it sinks below 10° above the south-western horizon. The apparent mag of Saturn will be 0.1 making it fairly bright. The exact time of opposition of Saturn will be 22:25 IST (16:55 GMT)

Position of Saturn at the time of exact opposition as seen from the Indian Capital. The pink dot in Ophiuchus is Jupiter. (Image: Dominic Ford, In-The-Sky)

Saturn will be angled to show its northern hemisphere at this opposition, and the rings will inclined at an angle of 24° to our line of sight, which is almost the maximum inclination they can have. This means they will be very well presented. Don't miss this opportunity to see the rings of this beautiful planet.

Also Read: Basics of Astrophysics Series

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