A dazzling fireball lit the skies in Sri Lanka last Wednesday, (18). The light was visible from most regions in the country. Eye witnesses in the southern regions had seen the shooting star that blazed across the sky as bright as daylight with a sizzling sound. The Dailymirror spoke to Astronomy experts in SL to gain more insight into the occurrence.
Prof. Chandana Jayaratne - Director of Astronomy and Space Science Unit, University of Colombo
“Undoubtedly it was a meteoroid. According to reports so far, a dazzling and smoking fire ball had been seen around 8.35 pm or 8.40 pm on October 18, moving from west to east in the night sky. It had been moving at a speed of about 65 -70 kmph and we guess it would have been around 10 - 50 cm in diameter,” Prof Jayaratne explained.
“The elements on a meteoroid can be identified by carefully observing its colour. This meteoroid was more yellowish with hues of green and blue, which indicated this as a stony iron-fortified meteoroid. Simply put, it must be a type of iron or stone. The meteoroid had blown up with a loud bang in the air, apparently above 50 - 200 km from sea level. This estimate was drawn by calculating the difference between the sight and the sound of explosion,” he explained.
Prof Jayaratne warned citizens of touching any debris left from the explosion since they might be highly radio active or poisonous. If any debris was found, he advised to shelter it with a wash basin or some other suitable- cover to prevent the debris coming into contact with water and inform Astronomy and Space Science Unit in Colombo University immediately. But he said finding debris from an explosion of a “stony” meteoroid is rare.
The giant fire ball was seen and the noise of its explosion was heard by many residents in the southern parts of Sri Lanka, mostly in Galle and Matara districts including Pitabeddara, Akuressa, Deniyaya, Pitiduwa, Habaraduwa, Weligama, and Hambantota. It has been visible from areas including Colombo, Hanguranketha, Matale and even Nuwara Eliya.
The giant fire ball was seen and the noise of its explosion was heard by many residents in the southern parts of Sri Lanka, mostly in Galle and Matara districts
“The meteoroid had appeared to be moving horizontally, after it rushed in from a great height,” he said.
Explaining the probable causes of how the meteoroid appeared here, he said the collision of two neutron stars in space has nothing to do with this incident. “Even though we are moving closer to the comet Hale- Bopp these days, it is most unlikely this meteoroid originated from the comet; it is too big,” Prof Jayaratne opined.He also informed that a meteor shower will be visible near the Orion Constellation from October 20 to 22.
It is definitely a meteoroid
“According to what we gathered from local media, this is definitely a meteoroid. A similar occurrence had taken place in Russia in 2013.” Saraj Gunasekera, Senior Research Scientist - Arthur C. Clarke Institute for Modern Sciences, Moratuwa, said.
Clarifying the misleading news in the social media and gossip sites, he said there is no relationship with the collision of two neutron stars in space with this meteoroid.
He requested eyewitnesses to send any genuine video footage they may have with them to the Arthur C. Clarke Institute to analyze them and submit a scientific explanation.
“This meteoroid was dark and as such it is of a kind that is difficult to observe hovering in space and foretell its time of arrival. However, the level of brightness and explosion makes this meteoroid special,” he said.
A web site named ‘Space Weather’ reported there were 1847 potentially hazardous asteroids near Earth on October 20, 2017.
An asteroid called 2017 TD5 with a diameter of 36 miles was predicted to pass Earth on Oct 18, missing it just by 11.2 LD (Lunar Distance or earth - moon distance). There was another much bigger Asteroid, 2006 TU 7 with a 148 mile diameter. Scientists noted that 2017 TD 6 - an asteroid was forecast to move much closer to Earth on October 19, missing Earth by 0.5 LD. “It is possible that the same asteroid hit Sri Lanka on Oct 18.” scintist Gunasekera said.
What happened back in 2013 in Russia?
“A small asteroid exploded over the city of Chelyabinsk, Russia, on Feb. 15, 2013. The shock wave it generated shattered glass and injured about 1,200 people. Some scientists think the meteor may have briefly outshone the sun. The blast was stronger than a nuclear explosion, detected by monitoring stations situated as far away as in Antarctica.”
“The incident was another reminder to space agencies about the importance of monitoring small bodies in space that could pose a threat to Earth. ” -(https://www.space.com/33623-chelyabinsk-meteor-wake-up-call-for-earth.html)
According to space scince literature available online, this meteor was known as a superbolide, a super bright meteor. It exploded at a height of 20 km above Earth releasing 500 kilotons of energy. Scientists were surprised to find a 650 kg meteorite (rock) from Lake Chebarkul in the debris after the explosion
The Chelyabinsk air burst seconds the “Tunguska Event” in 1908, the explosion of a 50 - 100 m wide fireball above the remote Taiga Forest in Siberia, flattening about 80 million trees near the Tunguska River. The area was uninhabited. The Tunguska event is considered to be the most powerful meteoroid explosion in history that produced 185 times more energy than the Hiroshima atomic bomb.
What is a meteoroid?
According to NASA’s website, asteroid and meteoroids are types of space rocks. An asteroid is a small rocky body orbiting the sun.
NASA explains that most asteroids in our solar system are found in the main asteroid belt, a region between Mars and Jupiter. But they can also hang out in other locations around the solar system. For example, some asteroids orbit the sun in a path that takes them near Earth.
NASA clarifies that when two asteroids smash into one another, small pieces break off and those are called meteoroids. If the meteoroid enters Earth’s atmosphere, it vapourises and turns into a meteor (a small rock) known as a shooting star.
