Credit: NASA

The partial solar eclipse will occur on Sep 21st, 2025. This eclipse happens just before the September equinox (around September 22), when day and night are nearly equal. This rare timing makes it an ‘equinox eclipse’, a once-in-a-lifetime event where cosmic motion aligns with the seasonal transition, offering skywatchers a truly unique celestial experience.

 

What is a Partial Solar Eclipse

A solar eclipse occurs when the Moon passes between Earth and the Sun, blocking some or all sunlight. In a partial solar eclipse, the Moon only covers part of the Sun, creating the appearance of a “bite” taken out of the Sun. This means skywatchers can witness a dramatic, rare phenomenon that transforms the Sun’s shape in a way not seen every day.

The September 21, 2025, event is a deep partial solar eclipse. “Deep” means the Moon will cover up to 85–86% of the Sun, creating a striking visual effect that’s perfect for observing or capturing in photographs — a rare opportunity for eclipse enthusiasts.

Credit: NASA

Why Do Solar Eclipses Happen

Credit: NASA

A solar eclipse occurs when the Moon passes directly between the Earth and the Sun, casting a shadow on Earth.

• The Moon has two shadows: the umbra (dark central shadow, where total eclipses are seen) and the penumbra (lighter outer shadow, where partial eclipses are visible).
• In this case, the Moon’s shadow only partially covers Earth, creating a partial solar eclipse.
• Eclipses don’t happen every new moon because the Moon’s orbit is tilted about 5° relative to Earth’s orbit around the Sun. Only when the new moon aligns closely with one of the orbital nodes (ascending or descending) can an eclipse occur.

This September 2025 eclipse occurs at the descending node and is part of Saros cycle 154, a series of eclipses repeating roughly every 18 years. This pattern helps astronomers predict future eclipses with precision, allowing enthusiasts to plan ahead and never miss these rare celestial events. A solar eclipse always occurs about two weeks before or after a lunar eclipse. Usually, there are two eclipses in a row, but other times, there are three during the same eclipse season.

 

When and Where: Visibility and Timing

2025 Partial Solar Eclipse Time:

Date	September 21, 2025
Start (UTC)	- 17:29 UTC
Maximum eclipse	- 19:41-19:43 UTC, when the Moon covers 85%-86% of the Sun
End (UTC)	- 21:53 UTC

 

Where It Will Be Visible:

• New Zealand - especially the southern parts (South Island, Stewart Island) will experience a large fraction of the Sun being covered.
• A thin eastern coast of Australia.
• Parts of Antarctica, including research stations.

 

If you’re in one of the ideal locations, here's what to expect:

• New Zealand: Southern areas will see up to 70-75% obscuration.
• Antarctic stations (e.g. McMurdo, Zucchelli) will see significant partial coverage — though not a total eclipse.
• Remote islands and oceanic areas between New Zealand and Antarctica will see nearly the deepest part of eclipse (≈ 80-86%).

Observers in many other places (e.g, much of the Northern Hemisphere) will not see it directly.

Eye Safety Reminder: Never look directly at the Sun without certified solar eclipse glasses — even during partial phases. Protecting your eyes ensures you can enjoy this spectacular event safely and without regret.

Recommended Astrophotography Cameras

For astrophotography enthusiasts, using professional planetary cameras can help capture stunning images of this partial solar eclipse. These cameras deliver high sensitivity, low noise, and excellent resolution, making it easier to photograph the dramatic eclipse even under challenging conditions.

G3M662M/G3M662C:

Entry-level high full-well planetary cameras with high sensitivity and excellent low-light performance.

G3M715C:

Entry-level planetary cameras with 4K high resolution, small pixels and low noise.

G3M678M/G3M678C:

Advanced planetary cameras with high resolution, superior sensitivity, and optimized pixel size.

G3M664C:

Advanced planetary cameras with 1/1.8” large sensor, 16:9 wide format and ultra-low noise.

G3M2210M/G3M2210C:

Advanced planetary camera with a large sensor and large pixels with superior sensitivity.