Three planets of the solar system are gearing up for their closest approach to the Earth in the coming weeks. They are Neptune, Mars, And Uranus. While Mars and Uranus will be at opposition in October, Neptune is going to make its closest approach this week. Here are three things that you must know:

1. What Is An 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.

Neptune Will Make Its Closest Approach To The Earth This Week: 3 Things To Know 1

During opposition, the planet lies opposite to the Sun. Hence, it rises around the sunset, reaches the highest point in the sky around midnight, and sets at dawn. This is the best time to observe a planet. Jupiter and Saturn were at opposition on July 14 and July 21 respectively. You can read this article to know how to watch them together.

At its opposition, a planet almost reaches its perigee (closest point to the Earth) and appears the biggest and brightest.

2. How Close Will Be Neptune

he average distance of Neptune from Earth is about 30.27 AU (1 AU = 150 million Km, the mean distance between Earth and Sun). At the opposition, the planet will be at 28.93 AU. This means the gas giant will be 201 million Km closer to Earth than its average distance.


Also read:

3. How To Watch This Event?

When a planet is at opposition, it is visible throughout the night. This happens because when Neptune lies opposite the Sun in the sky, the solar system is lined up so that Neptune, the Earth, and the Sun form a straight line with the Earth in the middle, on the same side of the Sun as Neptune.

Neptune Will Make Its Closest Approach To The Earth This Week: 3 Things To Know 2
Image: Dominic Ford, in-the-sky

The planet will make its closest approach exactly at 20:10 GMT on September 12. It will be well placed for observation, in the constellation Aquarius. It will be visible for much of the night, reaching its highest point in the sky at around midnight local time. Neptune will have an apparent magnitude of +7.8 so it won’t be visible with the unaided eye. You’ll need a telescope for that.

Don’t Forget!

Mars is now brighter than the brightest star in the night sky! Don’t forget to watch this stellar show of the Red Planet. This article will guide you in spotting Mars in the night sky.

Notify of
1 Comment
Inline Feedbacks
View all comments

What is the direction of Neptune in the sky

Would love your thoughts, please comment.x
Scroll to Top