Lunar eclipse of 2025 promises 82-minute blood moon spectacle

On September 7, 2025, the sky will host one of the year’s most anticipated astronomical events: a total lunar eclipse lasting 82 minutes, the longest of 2025. Known as a “blood moon” due to its reddish hue, the phenomenon occurs when Earth aligns between the Sun and the Moon, casting its shadow on the lunar surface. Although not directly visible in Brazil, the event can be followed through live streams on platforms like YouTube. Regions such as Europe, Africa, eastern Australia, and New Zealand will have prime viewing. The red hue results from sunlight filtered by Earth’s atmosphere, creating a unique visual spectacle. The eclipse will begin at 12:28 Brasília time and extend until 17:55, with the totality phase from 14:30 to 15:52. This will be the second lunar eclipse of the year, following one in March, and is expected to captivate millions worldwide.

The astronomical event is eagerly awaited by enthusiasts and scientists due to its exceptional duration and the Moon’s proximity to perigee, its closest point to Earth in its elliptical orbit. The reddish hue, a hallmark feature, depends on factors like volcanic dust and atmospheric pollution. In Brazil, the lack of direct visibility does not prevent viewers from experiencing the event, as digital platforms will offer real-time coverage. The blood moon combines science and natural beauty, sparking global curiosity.

• Total duration: 5 hours and 27 minutes, with 82 minutes of totality.
• Visibility: Europe, Africa, eastern Australia, and New Zealand.
• Streaming in Brazil: Platforms like YouTube and astronomy websites.
• Next eclipse in Brazil: March 2026, visible in the Americas.

The phenomenon reinforces humanity’s fascination with celestial events, uniting amateur and professional observers in a moment of awe and study.

Why the moon turns red

The reddish hue of the blood moon is one of the most intriguing aspects of a total lunar eclipse. When Earth blocks direct sunlight, some light is filtered through the atmosphere, scattering shorter wavelengths like blue and purple, while allowing red tones to reach the lunar surface. This process, known as refraction, creates the characteristic visual effect. The intensity of the color can vary depending on atmospheric conditions, such as the presence of dust or pollution.

In 2025, the Moon will be just 2.7 days from perigee, making it appear slightly larger and brighter in the sky. During the 82 minutes of totality, 36% of the lunar diameter will be immersed in the umbra, Earth’s darkest shadow, potentially resulting in a deeper hue. Astronomers note that such events offer a unique opportunity to study Earth’s atmosphere, as the Moon’s color directly reflects its conditions.

• Cause of the color: Refraction of sunlight through Earth’s atmosphere.
• Variation factors: Volcanic dust and atmospheric pollution.
• Eclipse depth: 36% of the lunar diameter in the umbra.
• Perigee proximity: Moon appears larger in the sky.

The visual spectacle, combined with its scientific value, makes the event a highlight of the 2025 astronomical calendar.

How the lunar eclipse happens

A total lunar eclipse occurs when the Sun, Earth, and Moon align perfectly, with Earth blocking direct sunlight from reaching the Moon. Earth’s shadow consists of two parts: the penumbra, lighter and outer, and the umbra, darker and central. The process unfolds in five distinct phases, each with unique visual characteristics.

Initially, the Moon enters the penumbra, undergoing a subtle darkening that is barely noticeable. In the partial phase, the umbra begins to cover part of the Moon, creating a striking contrast. During totality, the Moon is fully immersed in the umbra, displaying the reddish hue characteristic of a blood moon. After totality, the Moon gradually exits the umbra and returns to the penumbra, until the eclipse ends with the Moon free of Earth’s shadow.

• Eclipse phases: Penumbral, partial, totality, partial, penumbral.
• Totality duration: 82 minutes, from 14:30 to 15:52 (Brasília time).
• Best observation time: 75 minutes before totality.

The precision of this celestial alignment captivates scientists and observers, highlighting the dynamics of the solar system.

Where to follow the event

Although Brazil is not in the direct visibility area for the September 7 eclipse, Brazilians can follow the event through live streams. Platforms like YouTube and specialized websites, such as Time and Date, will offer real-time coverage with high-quality images. In regions with direct visibility, such as Europe and Africa, the eclipse can be observed with the naked eye, though binoculars or telescopes can enhance the experience.

In cities like Perth, Australia, the eclipse will occur between 1:30 and 2:52 local time on September 8. In Cairo, Egypt, it will be visible from 20:30 to 21:52 EEST. For optimal viewing, observers should seek locations with low light pollution and a clear horizon.

• Visibility locations: Europe, Africa, eastern Australia, New Zealand.
• Perth timings: 1:30 to 2:52, September 8.
• Observation tips: Dark locations with a clear horizon.
• Brazil alternative: Live streams on digital platforms.

Following the event, even virtually, will allow Brazilians to experience one of the year’s greatest astronomical spectacles.

Curiosities about the blood moon

The blood moon has long sparked fascination and narratives across cultures. In ancient times, the phenomenon was often interpreted as an omen or supernatural event. Today, science explains the red hue, but its visual impact continues to captivate people worldwide. The September 2025 eclipse will be special due to its long duration and the Moon’s proximity to perigee.

During totality, the Moon’s reduced brightness allows stars and constellations, such as Leo and the star Regulus, to become more visible, creating a unique celestial scene. The Moon’s hue can range from a vivid red to a darker tone, depending on factors like volcanic dust in the atmosphere.

• Cultural significance: Eclipses were once seen as omens.
• Stellar visibility: Stars more prominent during totality.
• Moon’s position: In Leo, near the star Regulus.
• Atmospheric influence: Dust can intensify the red hue.

The phenomenon connects science and history, offering a window into humanity’s past and present understanding.

Scientific value of the eclipse

Beyond its visual appeal, the September 2025 lunar eclipse holds scientific significance. Astronomers will use the event to study Earth’s atmosphere, as the Moon’s hue reflects the presence of particles like volcanic dust or pollutants. The eclipse’s depth, with 36% of the lunar diameter in the umbra, will allow detailed analyses of sunlight’s interaction with the atmosphere.

The event is part of the Saros cycle, a series of lunar eclipses repeating every 18 years and 11 days. The 2025 eclipse belongs to series 123, which includes 72 events, with the next major one expected in 2043. These data help scientists better understand lunar orbits and solar system dynamics.

• Saros cycle: Repeats every 18 years and 11 days.
• Atmospheric studies: Hue reflects dust and pollution.
• Next series eclipse: Expected in 2043.

The eclipse underscores the importance of astronomical events for scientific advancements and inspires new generations of researchers.