Neptune, the eighth and farthest planet from the Sun, is set to be prominently visible from Earth as it reaches opposition.
The planet with a greenish blue tinge is reaching opposition on September 21, 2024, when it will be most clearly visible. However, it is rising in the night skies across India tonight.
This astronomical event occurs when Earth passes directly between Neptune and the Sun, allowing skywatchers to catch a glimpse of this distant ice giant, which is typically invisible to the naked eye.
Neptune is going through opposition. A planetary opposition occurs when a planet is directly opposite the Sun from Earth's perspective.
This means the Earth is positioned between the planet and the Sun, making the planet appear fully illuminated and usually brighter in the night sky. It is also the best time to observe planets, as they are closest to Earth during opposition.
Neptune will be in opposition on September 21, when it will be most visible from Earth. The opposition is a once-in-a-year event for Neptune making it a rare event for skywatchers to not miss.
Neptune will shine at a magnitude of +7.8, making it its brightest for the year.
However, due to its faintness—about five times dimmer than the dimmest stars visible in dark skies—viewing it requires binoculars or a telescope.
For observers in India, particularly in New Delhi, Neptune will be visible throughout most of the night on September 20-21, rising in the east just as the sun sets in the west.
The planet will appear as a distinct tiny blusih dot in the sky, when seen with a telescope.
Neptune's distinctive bluish-green hue is a result of methane in its atmosphere, which absorbs red light.
The planet lies on the inner edge of the Kuiper Belt, a region filled with icy bodies and dwarf planets like Pluto and Eris. With an atmosphere primarily composed of hydrogen and helium, Neptune features a slushy interior of rocky and icy materials.
To locate Neptune in the night sky, enthusiasts can look towards the constellation Pisces.
It will be positioned southeast of Lambda Piscium, a star that serves as a good reference point for finding the planet. Through a telescope, observers may see Neptune as a small disk rather than just a point of light.
This opposition presents an excellent opportunity for astronomers and casual stargazers alike to explore our solar system's most distant major planet.
As Neptune reaches its closest point to Earth — approximately 28.9 astronomical units away — its visibility will remain strong through February 2025, allowing ample time for observation and study of this fascinating world.
Source: India Today