Science wrap: Ozone layer shrinkage, partial solar eclipse, and a cyclone in Bangladesh
Given that this week marked Diwali, air pollution levels were bound to be on a destructive high. Away from the haze, the day after Diwali was also marked by the country witnessing a partial solar eclipse. However, the northeastern parts of the country were still alerted due to the raging cyclone Sitrang that devastated parts of Bangladesh.
Elsewhere on the global scale, the planet marred with climate change got a rare good news with the ozone hole in the stratosphere’s ozone layer projecting a slight decrease in size.
1- The ozone layer witnesses a shrinkage, slight hope for Earth
As is common knowledge, the stratosphere within the Earth’s atmosphere houses the ozone layer which protects the planet from the Sun’s harmful UltraViolet (UV) radiations. However, ever since the usage of CFCs (ChloroFlouroCarbons) increased in collants, propellants, refrigerators, and ACs, the ozone layer started thinning with a hole being created in it.
The hole has however improved as compared to the 90s and 2000s standards. Just last year, the hole’s area was estimated at 24.8 million square kilometers. This year, according to the September-October estimates, the area is now 23.2 million square kilometers. It is a slight yet notable decrease.
NASA experts suggest that this might be the direct impact of the 1987 Montreal Protocol, the global agreement that called for phasing out usage and production of CFCs. Almost all of the 198 member states of the United Nations ratified the protocol since its inception.
2- Partial solar eclipse in India
When the Sun, Moon, and Earth get aligned together (not always in a straight line though), a partial solar eclipse is observed. In India, the last time such a phenomenon happened was back in 2007 with the latest one taking place on October 25 this year. The next time such an eclipse will be witnessed by Indians is estimated to be in November, 2032. While 2025 will also witness a partial solar eclipse, it will be out of India’s view.
Tuesday’s eclipse lasted the longest in Gujarat’s Dwarka with the event in total taking place at an estimate of 1 hour and 45 minutes.
3- Crater caused by biggest meteorite strike in Mars detected
Last Christmas Eve, a “Mars quake” of magnitude 4 was detected on the Red Planet by NASA’s InSight lander. The seismic activity was unprecedented and connected to a meteorite strike. Since then, the NASA spacecraft were intent on detecting the crater impact.
Finally, NASA’s Mars Reconnaissance Orbiter has now managed to capture stunning images of the subsequent crater in the Amazonis Plantitia region while InSight managed to measure the seismic shocks. The strike’s impact crater has a circumference of 490 feet (150 metres) and is 70 feet (21 metres) deep.
While such craters are found on the planet’s surface in abundance, most of them are primitive and were formed way before NASA began exploring outer space. The freshness of this crater is what makes the find more unique.
4- Cyclone Sitrang mainly affects Bangladesh along with some NE states
The first tropical cyclone of this year’s post-monsoon season was christened Sitrang with the cyclone wreaking havoc in the low-lying areas of Bangladesh. States like Mizoram and Assam were also put under security alert situations such as red alert and orange alert with unexpectedly high rainfall and winds.
Even though now the Indian Meteorological Department (IMD) has classified the cyclone’s current status as a low common land pressure, Sitrang caused 35 fatalities and the destruction of over 10,000 houses.