Halley’s Comet Debris to Streak Across Brazilian Sky
Twenty or more meteors per hour will streak across the Brazilian sky this Wednesday (21), fed by ancient debris left behind by Halley’s Comet.
The Science of the Halley Debris Trail
The celestial display runs from October 2 to November 7 as Earth passes through the densest and dustiest trail of debris left by Halley’s Comet. When these fragments hit the atmosphere at speeds reaching approximately 66 kilometers per second, they burn up and create bright luminous streaks. The comet takes approximately 75 to 76 years to complete its orbit around the Sun, with its last passage occurring in 1986 and its next return to the proximity of the Sun slated for 2061. The Halley also gives rise to another meteor shower, the Eta Aquariids, observed in May.
Moonlight Obscures Meteors During Regional Visibility Windows
With the Moon illuminated at roughly 75% to 77% of its disk during the peak, its brightness threatens to obscure fainter meteors. Observers are advised to watch the night sky after the Moon sets and before morning twilight breaks.
Local visibility windows vary by region:
Recife: 1:20 a.m. and 3:43 a.m.
Fortaleza: 1:31 a.m. and 4:02 a.m.
Rio de Janeiro: 2:09 a.m. and 3:57 a.m.
São Paulo: 2:24 a.m. and 4:10 a.m.
Porto Alegre: 2:51 a.m. and 4:16 a.m.
Geographic Advantages in the North
Northern and northeastern regions hold a slight advantage because the radiant point rises higher in the sky. This lengthens the unilluminated viewing window before dawn, according to Project Exoss coordinator Marcelo De Cicco.
Tracing the Orionid Radiant Point
The meteor shower derives its name from the constellation Orion. The radiant point appears near the star Betelgeuse and the well-known belt asterism known as the Three Sisters, or Três Marias.
Essential Tips for Naked-Eye Observation
Astronomers emphasize that viewers do not need to look directly at Orion, as meteors can appear across various sectors of the night sky. Telescopes and binoculars are unnecessary and can actually hinder observation by restricting the field of view, though they remain useful for viewing the Moon. Observers should seek dark locations away from heavy urban light pollution and allow about 30 minutes for their eyes to adapt to the dark.