Category Earth Science

Is Earth the only planet that supports life?

Discovery about an Earth-like planet orbiting an M dwarf could imply that planets orbiting the most common star may be uninhabitable.

Is Earth the only planet that supports life? This is one of the many questions for which we don’t have an answer yet. In a universe filled with countless stars and innumerable planets, our quest for life on a planet other than our own continues.

A new discovery could serve as a signpost and maybe even dramatically narrow our search for life on other planets. The discovery, explained in the Astrophysical Journal Letters in October by researchers from the University of California – Riverside, reveals that an Earth-like planet orbiting an M dwarf appears to have no atmosphere at all.

Most common type of star M dwarfs or red dwarfs are the most common type of star in the universe. This discovery could therefore imply that a large number of planets orbiting these stars may also lack atmospheres, and will therefore likely not support life.

The planet named GJ 1252b is slightly larger than our Earth, but is much closer to its star, an M dwarf, than the Earth is to the sun. On a single day on Earth, this planet orbits its star twice.

In order to find out if this planet lacks an atmosphere, astronomers measured infrared radiation from the planet as its light was during a secondary eclipse. In a secondary eclipse, the planet passes behind the star, and hence the planet’s light along with the light reflected from its star are blocked.

Scorching temperatures

The radiation revealed the planet’s daytime temperatures to be of the order of 2,242 degrees Fahrenheit. This, along with assumed low surface pressure, led the astronomers to believe that GJ 1252b lacks an atmosphere.

The researchers concluded that the planet will not be able to hold on to an atmosphere, even if it had tremendous amounts of carbon dioxide, which traps heat. Even if an atmosphere builds up initially, it would taper off and erode away eventually.

With M dwarf stars having more flares, the likelihood of planets surrounding them closely holding onto their atmospheres goes down further. The lack of atmosphere means that life as we know it is unlikely to flourish.

In Earth’s  solar neighbourhood, there are about 5,000 stars and most of them are M dwarfs. If planets surrounding them can be ruled -out entirely in the search for life based on this discovery, that would leave roughly around 1,000 stars similar to the sun that could be habitable.

For now, however, these can’t be ruled out entirely. Nor can we rule out the possibility of a planet far enough away from an M dwarf star such that it retains its atmosphere. We need more research and results as we continue to embark on our search for life elsewhere.

Picture Credit : Google 

WHAT IS THE PURPOSE OF THE INDIA METEOROLOGICAL DEPARTMENT (IMD)?

The India Meteorological Department (IMD) is an agency of the Ministry of Earth Sciences of the Government of India. It is the principal agency responsible for meteorological observations, weather forecasting and seismology. IMD is headquartered in Delhi and operates hundreds of observation stations across India and Antarctica. Regional offices are at Chennai, Mumbai, Kolkata, Nagpur, Guwahati and New Delhi.

IMD is also one of the six Regional Specialised Meteorological Centres of the World Meteorological Organisation. It has the responsibility for forecasting, naming and distribution of warnings for tropical cyclones in the Northern Indian Ocean region, including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf.

In 1686, Edmond Halley published his treatise on the Indian summer monsoon, which he attributed to a seasonal reversal of winds due to the differential heating of the Asian landmass and the Indian Ocean. The first meteorological observatories were established in India by the British East India Company. These included the Calcutta Observatory in 1785, the Madras Observatory in 1796 and the Colaba Observatory in 1826. Several other observatories were established in India during the first half of the 19th century by various provincial governments.

The Asiatic Society, founded in Calcutta in 1784 and in Bombay in 1804, promoted the study of meteorology in India. Henry Piddington published almost 40 papers dealing with tropical storms from Calcutta between 1835 and 1855 in The Journal of the Asiatic Society. He also coined the term cyclone, meaning the coil of a snake. In 1842, he published his landmark thesis, Laws of the Storms.

After a tropical cyclone hit Calcutta in 1864, and the subsequent famines in 1866 and 1871 due to the failure of the monsoons, it was decided to organise the collection and analysis of meteorological observations under one roof. As a result, the India Meteorology Department was established in 1875. Henry Francis Blanford was appointed the first Meteorological Reporter of the IMD. In May 1889, Sir John Eliot was appointed the first Director General of Observatories in the erstwhile capital, Calcutta. The IMD headquarters were later shifted to Shimla in 1905, then to Pune in 1928 and finally to New Delhi in 1944.

IMD became a member of the World Meteorological Organisation after independence on 27 April 1949.[4] The agency has gained in prominence due to the significance of the monsoon rains on Indian agriculture. It plays a vital role in preparing the annual monsoon forecast, as well as in tracking the progress of the monsoon across India every season.

The IMD is headed by the Director General of Meteorology, currently Dr. Mrutyunjay Mohapatra. IMD has six Regional Meteorological Centres, each under a Deputy Director General. These are located in Chennai, Guwahati, Kolkata, Mumbai, Nagpur and New Delhi. There is also a Meteorological Centre in each state capital. Other IMD units such as Forecasting Offices, Agrometeorological Advisory Service Centers, Hydro-meteorological Office, Flood Meteorological Offices, Area Cyclone Warning Centers and Cyclone Warning Centers are usually co-located with various observatories or meteorological center.

IMD undertakes observations, communications, forecasting and weather services. In collaboration with the Indian Space Research Organisation, the IMD also uses the IRS series and the Indian National Satellite System (INSAT) for weather monitoring of the Indian subcontinent. IMD was first weather bureau of a developing country to develop and maintain its own satellite system.

IMD is one of the six worldwide Regional Specialised Meteorological Centres of the Tropical Cyclone Programme of the World Weather Watch of the World Meteorological Organization. It is regional nodal agency for forecasting, naming and disseminating warnings about tropical cyclone in the Indian Ocean north of the Equator.

Credit : Wikipedia

Picture Credit : Google 

WHAT ARE FOSSIL FUELS?

Fossil fuels are formed from decomposed plants and animals that lay buried deep inside the earth for millions of years. With the progress of time, heat and pressure turn these remains into fossil fuels. The most common ones are coal, crude oil (petroleum) and natural gas. They have multiple uses (from generating electricity and powering vehicles and planes to heating homes). Fossil fuels are nonrenewable and can harm the environment since the carbon stored in them gets released into the atmosphere as carbon dioxide, a greenhouse gas that causes global warming.

According to the National Academies of Sciences, 81 percent of the total energy used in the United States comes from coal, oil, and natural gas. This is the energy that is used to heat and provide electricity to homes and businesses and to run cars and factories. Unfortunately, fossil fuels are a nonrenewable resource and waiting millions of years for new coal, oil, and natural gas deposits to form is not a realistic solution. Fossil fuels are also responsible for almost three-fourths of the emissions from human activities in the last 20 years. Now, scientists and engineers have been looking for ways to reduce our dependence on fossil fuels and to make burning these fuels cleaner and healthier for the environment.

Scientists across the country and around the world are trying to find solutions to fossil fuel problems so that there is enough fuel and a healthy environment to sustain human life and activities in the future. The United States Department of Energy is working on technologies to make commercially available natural-gas-powered vehicles. They are also trying to make coal burning and oil drilling cleaner. Researchers at Stanford University in California have been using greener technologies to figure out a way to burn fossil fuels while lessening their impact on the environment. One solution is to use more natural gas, which emits 50 percent less carbon dioxide into the atmosphere than coal does. The Stanford team is also trying to remove carbon dioxide from the atmosphere and store it underground—a process called carbon capture and sequestration. Scientists at both Stanford and the University of Bath in the United Kingdom are trying something completely new by using carbon dioxide and sugar to make renewable plastic.

Credit : National geographic

Picture Credit : Google 

WHAT IS THE FARTHEST WE HAVE GONE INTO THE EARTH?

What is the furthest down humans have gone? What is the Kola superdeep Borehole? Read on to find the answers.

In Jules Verne’s science fiction novel, Journey to the Centre of the Earth (1864), three men reach the centre of the Earth. Is this ever possible? Our planet is made up of three main layers- the crust, the mantle and the core. The continents and oceans are situated on the crust which is about 8 km thick under the oceans and between 35 and 40 km deep under the continents. Below the crust is the mantle which is about 2,900 km thick. Next comes the core. The outer core, about 2.250 km thick, is made up of melted iron and nickel, and contained within it, is a ball-shaped inner core believed to be made up of solid iron and nickel.

The centre of the innermost core is the centre of the Earth. So there are thousands of kilometres to descend to reach the centre of the Earth, and what is the furthest down we’ve gone? When the Russians and the Americans were engaged in a race to the moon several decades ago, they also embarked on a race to inner space to see how far down they could go. While the Americans did not make much headway in this race downwards (Project Mohole’), the Russians went at it, hammer and tongs, in the Kola Peninsula and dug a hole 12.262 km deep over a period of 24 years from 1965 to 1989. They wanted to go at least 15 km down,  but just could not. This is the closest we’ve been able to go to the centre of the Earth. The Kola Superdeep Borehole, as it is now called, attracts curious visitors from around the world.

Picture Credit : Google 

WHAT IS THE DIFFERENCE BETWEEN PHYSICAL AND CHEMICAL WEATHERING?

Physical weathering is also known as mechanical weathering. It is a process, initiated by humans, plants or animals, which breaks down rocks and minerals on the surface of Earth. It changes just the shape or size of the rocks and minerals. Chemical weathering, on the other hand, happens when the chemical composition of the rock and soil changes, forming new chemical combinations and a different internal structure.

Physical weathering is also called as mechanical weathering. This is the process where rocks breakdown without altering their chemical composition. Physical weathering can occur due to temperature, pressure or snow. There are two main types of physical weathering. They are freeze thaw and exfoliation.

Freeze-thaw is the process where water goes into the cracks of the rock, then freezes and expands. This expansion causes rock to break apart. Changing temperature also causes rocks to expand and contract. When this happens over a period of time, rock parts starts to break down. Due to the pressure, cracks can be developed parallel to the land surface which leads to exfoliation.

Physical weathering is prominent in the places where there is little soil and few plants. For example, in desserts surface rocks are subjected to regular expansion and contraction due to temperature changes. Also, in mountain tops, snow keeps melting and freezing which causes physical weathering there.

Chemical weathering is the decomposition of rocks due to chemical reactions. This changes the composition of the rock. This often takes place when rain water reacts with minerals and rocks. Rain water is slightly acidic (due to dissolution of atmospheric carbon dioxide, carbonic acid is produced), and when the acidity increases chemical weathering also increases. With the global pollution, acid rains occur now, and this increases chemical weathering more than the natural rate.

Other than water, temperature is also important for chemical weathering. When the temperature is high, the weathering process is also high. This releases minerals and ions in rocks into surface waters. There are three main types as to how the chemical weathering occurs. They are solution, hydrolysis and oxidation. Solution is the removal of rock in solution due to acidic rain water. This is sometimes called carbonation process, since the rain water acidity is due to carbon dioxide. Hydrolysis is the breakdown of rock to produce clay and soluble salts by acidic water. Oxidation is the breakdown of rock due to oxygen and water.

Credit: differencebetween.com

Picture Credit : Google