The Southern Cross, near where the meteor fragment passed.
© Wikimedia.
The Southern Cross, near where the meteor fragment passed.
A resident was astounded when he spotted a large fireball while stargazing at Kaapmuiden last week. He approached an astronomical expert to find out what it was.

A resident spotted a massive fireball in the sky, the result of a falling meteor fragment, while stargazing last Tuesday at 19:35.

Bertus van der Merwe said he was standing outside his house, looking south, when a large fireball came from the east, moved west over the treetops and exploded. He was stunned and mesmerised, as it wasn't just a light, he could make out flames.

He said when he went back into his house, he joked that he now knew where the expression "great balls of fire" comes from.

Van der Merwe found a fireball report form on the Internet and sent it to Tim Cooper of the Astronomical Society of Southern Africa for answers.

Given the size and brightness of the fireball, Cooper stated that it might have been a large meteor fragment. After determining Van der Merwe's location, Cooper plotted the path the meteor may have followed.
He stated that it might have started just below and to the left of the Two Pointers to the lower left of the Southern Cross, passed below the Southern Cross and above Canopus, the second brightest star in the sky, while it was disintegrating.
Cooper traced the fireball back to Scorpius, which is a known source of bright meteors at this time of the year.

He explained that the meteors spotted by stargazers every night are debris left behind by comets.

Earth is hit by about 10 000 tons of this debris every day, most of which is about the size of a sand grain or smaller.

The meteor expert believes the object Van der Merwe saw was about the size of a small stone.
"It was so bright because it was travelling at about 50 kilometres per second and heated the gases in the atmosphere to incandesce. So it was not the meteor you saw, but its effects on the atmosphere."
"The effects of this heating may cause the particle to fragment or break up into smaller pieces during its flight," Cooper wrote to Van der Merwe.

Meteors are objects that are large enough to survive the heating process and reach the ground. Meteorites have a different source and are mostly fragments of asteroids. They are much larger than the dust left behind by comets and therefore cause brighter fireballs.

"Depending on the brightness it could be that your fireball was from a fragment of asteroid, travelling randomly through space," he stated.

Cooper said that most meteors from comets are associated with streams and, if the details are all correct, Van der Merwe's fireball coincides with one of the streams active during May each year. He stated that he studied the stream in detail in the 1980s and that it rarely produced bright meteors.

The orbit of the original particle can be determined if there are accurate measurements of the path, but another observer from a different location is needed to triangulate the trajectory.

So far only Van der Merwe's observation has been reported and he's eager to learn more about the sighting.