Category Science

When boreal forests burn?

A large portion of our planet’s land surface is covered by forests (of different types). These include tropical, subtropical temperate, and boreal forests. While forests the world over are threatened by global warming boreal forests grapple additionally with an issue unique to them. What is it? Come; let’s find out the boreal forests of the northern hemisphere span Scandinavia, Siberia, Alaska, and Canada. Due to this vastness and the sheer number of trees they hold, these forests are an important carbon sink. Carbon has also accumulated over thousands of years in the soil due to the (long) time it takes for dead organic matter to decompose, thanks to the region’s cold climate and water-logged ground. The ecosystems here have been shaped mainly by “wildfires ignited by lightning” During these fires, due to the quantum of carbon it holds, a boreal forest “will release 10 to 20 times more carbon compared to a similarly sized fire in other ecosystems”. But then, unlike most other types of forests, these forests “might burn only once a century, sometimes even less often than that”. Because of this frequency, the amount of carbon stored has always exceeded that of carbon released into the atmosphere; it has been so for at least 6,000 years now. But now global warming is threatening this delicate balance.

Due to rising global temperatures, the fire season has become longer, leading to an increase in the frequency and severity of wildfires. As the “interval between fires shortens, more carbon is being released from organic soils in boreal forests than the ecosystems can reabsorb”. A new study shows a dramatic spike “in emissions from boreal fires over the past two decades”. In 2021 alone, they showed “a record 23% of global vegetation wildfire emissions, more than twice their contribution in a more typical year. If such spikes continue, it is likely that boreal forests may soon become a significant source of global emissions from biomass burning.

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What’s a living fossil?

Living fossils are those species that have retained the same form over millions of years. They have few or no living relatives. Most of these animals have changed relatively little since their origins.

Did you know that some archaic species that lived millions of years ago have survived for a long time and still live alongside us? The anatomy of these species has remained unchanged and these relics of the past are called living fossils.

The term “living fossil” refers to those species that have retained the same form over millions of years. They have few or no living relatives. Most of these animals have changed relatively little since their origins. They have often survived several mass extinctions.

It was English naturalist Charles Darwin who introduced the concept of a “living fossil”. He coined the term in his book On the Origin of Species (1859). He described them as species that are still in existence but belonging to an old lineage. While most species have been evolving, these underwent slow rates of evolution. The appearance of these are mostly unchanged from their extinct fossil relatives.

They have survived from an earlier period or in a primitive form, have long-enduring lineages and also belong to a group with low diversity. Their DNA has hardly changed in millions of years.

Some examples of living fossils include coelacanths, horseshoe crabs, tuataras, komodo dragon, aardvark, red panda, nautilus and purple frog. The tree Ginkgo biloba is the only living species of its group. It dates back almost 300 million years in the fossil record.

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Naming planetary objects?

On August 23, India celebrated a technological triumph when Chandrayaan-3 landed near the Moon’s South Pole at 6:04 p.m. Since then, there has been a discussion on the naming of the landing spot, which Prime Minister Narendra Modi has termed Shiv Shakti.

Do you know how are planetary objects are usually named?

International Astronomical Union             

The International Astronomical Union (IAU), founded in 1919, is responsible for assigning names to celestial bodies and surface features on them. In the IAU, there are numerous Working Groups that suggest the names of astronomical objects and features.

In 1982, the United Nations, at its ‘Fourth Conference on the Standardisation of Geographical Names held in Geneva, recognised the role of the IAU by adopting its resolution on extraterrestrial feature names.

Key rules

The IAU has set some rules for naming planetary objects. Some of the most important rules are -the names should be simple, clear, and unambiguous; there should not be duplication of names; no names having political, military or religious significance may be used, except for names of political figures prior to the 19th Century; and if a name of a person is suggested, then he/she must have been deceased for at least three years, before a proposal may be submitted.

Process of naming

When the first images of the surface of a planet or satellite are obtained, themes for naming features are chosen and names of a few important features are proposed, usually by members of the appropriate IAU Working Group. However, there is no guarantee that the name will be accepted.

Names reviewed by an IAU Working Group are submitted by the group’s chairperson to the Working Group for Planetary System Nomenclature (WGPSN). After this, the members of the WGPSN vote on the names.

The names approved by the WGPSN members are considered as official IAU nomenclature and can be used on maps and in publications. The approved names are then entered into the Gazetteer of Planetary Nomenclature, and posted on the website of IAU.

Objections

If there are any objections to the proposed names, an application has to be sent to the IAU general secretary within three months from the time the name was placed on the website. The general secretary will make a recommendation to the WGPSN Chair as to whether or not the approved name(s) should be reconsidered.

 In 1966, the Outer Space Treaty was formed by the United Nations Office for Outer Space Affairs to set rules for international space law. One of the key aspects of this treaty was that the outer space, including the moon and other celestial bodies, shall be free for exploration and use by all states without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.

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In a tearing hurry?

Climate change is making hurricanes wetter, windier and altogether more intense. There is also evidence that it is causing storms to travel more slowly, meaning they can dump more water in one place.

If it were not for the oceans, the planet would be much hotter due to climate change. But in the last 40 years, the ocean has absorbed about 90% of the warming caused by heat-trapping greenhouse gas emissions. Much of this ocean heat is contained near the water’s surface. This additional heat can fuel a storm’s intensity and power stronger winds.

Climate change can also boost the amount of rainfall delivered by a storm. Because a warmer atmosphere can also hold more moisture, water vapour builds up until clouds break, sending down heavy rain. During the 2020 Atlantic hurricane season-one of the most active on record – climate change boosted hourly rainfall rates in hurricane-force storms by 8%-11%, according to an April 2022 study in the journal Nature Communications.

The world has already warmed 1.1 degrees Celsius above the pre-industrial average. Scientists at the U.S. National Oceanic and Atmospheric Administration This image obtained from the National Oceanic and Atmospheric Administration (NOAA), shows Hurricane Idalia making landfall in Florida on August 30, 2023. AFP (NOAA) expect that, at 2 degrees Celsius of warming, hurricane wind speeds could increase by up to 10%. NOAA also projects the proportion of hurricanes that reach the most intense levels Category 4 or 5- could rise by about 10% this century. To date, less than a fifth of storms have reached this intensity since 1851.

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Clean, sustainable fuels from industrial waste?

As we strive towards a future where net-zero emission becomes a reality, the need for clean. sustainable fuels has become more important than ever before. There’s been some progress along those lines as a group of researchers from the University of Cambridge have developed a solar-powered reactor that converts captured CO and plastic wastes into sustainable fuel and other useful chemical products.

 In the tests that were conducted, CO was converted into syngas, which is a key component for sustainable liquid fuels. Plastic wastes, meanwhile, were converted into glycolic acid, which is widely used in the cosmetics industry. The results were reported in the journal Joule in June

Inspired by photosynthesis

 This research group has been working towards developing sustainable, net-zero carbon fuels for several years. Their technology was inspired by photosynthesis, which is the process employed by plants to convert sunlight to food. Most of their solar-driven tests using artificial leaves until now, however, used pure, concentrated

CO2 from a cylinder. For this research, the team took CO2 from real-world sources such as industrial exhaust or even the air itself. By capturing and concentrating the CO2, they were then able to convert it into sustainable fuel.

Carbon capture and utilisation

For this, they were inspired by the carbon capture and storage (CCS) popular in the fossil fuels industry wherein CO2 is captured and then pumped underground and stored. But rather than storing it with unknown long-term implications, this group focussed on carbon capture and utilisation.

By bubbling air through the system with an alkaline solution, they were able to selectively trap the CO2. Other gases like nitrogen and oxygen, meanwhile, bubbled out harmlessly. The bubbling process thus made the air or the exhaust easier to work with, as CO2 could be concentrated.

The integrated system allowed the researchers to convert CO2 and plastics into fuels and chemicals using just the power of the sun. While improvements are definitely needed for this technology to be used at scale, the positive results are a step towards producing clean, sustainable fuels to power the world.

As we strive towards a future where net-zero emission becomes a reality, the need for clean. sustainable fuels has become more important than ever before. There’s been some progress along those lines as a group of researchers from the University of Cambridge have developed a solar-powered reactor that converts captured CO and plastic wastes into sustainable fuel and other useful chemical products.

 In the tests that were conducted, CO was converted into syngas, which is a key component for sustainable liquid fuels. Plastic wastes, meanwhile, were converted into glycolic acid, which is widely used in the cosmetics industry. The results were reported in the journal Joule in June.

Picture Credit : Google

 

What does mercury in retrograde mean ?

Mercury is the closest planet to the San whipping around our star every 88 days compared to Earth 365.25 days. Mercury will also be the first planet destroyed when the Sun expands on its way to becoming a real giant in about 5 billion years.

So it seems a bit rough that we blame Mercury for all our problems three to four times a year when its in retrograde. But what does it mean when we say Mercury is in retrograde?

A matter of orbits

Retrograde motion means a planet is moving in the opposite direction to normal around the Sun. However, the planets never actually change direction. What we are talking about is apparent retrograde motion, when to us on Earth it looks like a planet is moving across the sky in the opposite direction to its usual movement Because Mercing is closest to the Sun and has the fastest orbit, it appears to move backwards in the sky more often than any other planet. But Mercury isn’t the only planet to do this. Venus also orbits. Inside our oririt of the Sun, ripping around once every 224-7 days. This means Venues is in retrograde twice every three years.

There is also another retrograde. It works the other way around, too. The planets outside our orbit (Mars, jupiter, Saturn Uranus, and Neptune) also go into retrograde. Mars is in retrograde once every two years. The other planets are so far from the Sun and travelling so slowly compared to Earth that its almost like they’re standing still. So we see them in retrograde approximately once a year as we whip around the Sun so much faster than they do

A well-known illusion

Retrograde motion bumboozled act astronomers since humans started looking up in space, and we only officially figures it out when Copernicus proposed in 1543 that the planets are orbiting the Sun (though he wasn’t the first astronomer to propose this heliocentric model).

Before Copernicus, many astronomers thought Earth was the centre of the universe and the planets were spinning around us. Astronomers like Apollonius around 300 BCE saw the planets going backwards, and explained this by adding more circles called epicycles. So, humans found out retrograde motion was an optical illusion 500 years ago. However, the pseudoscientific practice of astrology continues to ascribe a deeper meaning to this illusion.

There’s a retrograde most of the time

 If we consider the seven planets other than Earth, at least one planet is in retrograde for 244 days of 2023 – that’s around two-thirds of the year.

If we include the dwarf planets Pluto and Ceres (and exclude the other seven dwarf planets in the Solar System), at least one planet or dwarf planet is in retrograde for 354 days of 2023, leaving only 11 days without any retrograde motion.

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