Trivia

Hard

Brief Bright Flashes In The Night Sky Called “Iridium Flares” Are Caused By?

Solar Flares
Dying Comets
Satellite Antennas
Blackholes Collapsing
Photo of an iridium flare taken in Perschling, Austria.
Peter Nussbaumer/Wikimedia

Answer: Satellite Antennas

If you gaze up at the night sky long enough, you’re bound to see an interesting thing or two. Shooting stars, occasional atmospheric disturbances, and every once in a great while, a brilliant flash that might catch an ordinary viewer off guard.

These bright flashes aren’t a natural phenomenon, however, but a side effect of the large network of 66 communication satellites that make up the Iridium satellite constellation (that provides global service to satellite-based phones, pagers, and integrated transceivers). The vast majority of satellites in the night sky are completely invisible to us thanks to their small size and lack of large reflective surfaces. The satellites in the Iridium constellation, however, feature large door-sized antennas covered in a polished and highly reflective material.

Most of the time, the alignment of the satellites is off just enough so that they don’t reflect sunlight towards Earth, but when they do, the reflection shines down like a giant flashlight. For a brief moment, they are the brightest thing in the night sky—each flash is visible over a 6.2 mile (10 kilometer) diameter area below. The flashes can be so bright they even, rarely, appear to viewers during the daytime who happen to be looking at the right place at the right time in the sky above.

Trivia

Hard

The First Commercial Reprogrammable Machines Were Used For?

Trivia

Easy

The First Wearable Computer Was Used For What?

Trivia

Hard

Which Of These Sci-Fi Ships Was Once Slated For A Full-Size Replica In Las Vegas?

Trivia

Hard

In The Late 19th Century People Put Out Home Fires With?

Trivia

Hard

Which PC Game Was The First to Be Flown Into Space?

Trivia

Hard

Which Planet Will Eventually Consume Its Own Moon?

Trivia

Hard

Which U.S. State Has The Most Lighthouses?

Trivia

Easy

The Only Author To Have A Unique Dewey Decimal Number Devoted To Them Is?

Trivia

Easy

The Screen Of Space Invaders Was Colored By What?

Trivia

Hard

The Dendy Was A Soviet Clone Of Which Popular Game Console?