New Delhi: Scientists have found evidence of three new salty lakes buried under the surface of Mars’ south pole. They have also confirmed the existence of a fourth lake that was first detected two years ago. The discovery of subsurface water has raised the possibility of Martian life.
The findings were made using satellite radar data from the Mars Express, the European Space Agency’s Mars orbiter. The data set comprised of 134 observations between 2012 and 2019.
The radar on Mars Express, called the Mars Advanced Radar for Subsurface and Ionosphere Sounding, sends out radio waves that bounce off a planet’s surface and its subsurface. The ways in which these signals get reflected hold clues to what the surface of a particular location is made up of — rock, ice or water.
In the case of Mars, the scientists had detected bodies of liquid water trapped under more than one kilometre of Martian ice. These lakes were found to be spread over nearly 75,000 square kilometres.
The largest, central lake, is spread across 30 kilometres, and is surrounded by three smaller lakes, each a few kilometres wide.
While lack of atmosphere and liquid water on Mars’ surface makes the existence of life impossible, water trapped under its surface could be potential habitats for Martian life. Read more about it on the BBC.
Einstein’s theory of general relativity passes the ‘black hole shadow test’
Albert Einstein’s theory of general relativity — which predicted that the space-time around earth would be not only warped but also twisted by the planet’s rotation — has passed what is known as the ‘black hole shadow test’.
In this test, scientists used the first ever image of a black hole to see if its size is consistent with what was predicted by the mathematical equations Einstein had written over a 100 years ago.
The image of a shadow of M87* — a supermassive black hole located at the centre of the M87 galaxy — was the first time a telescope was able to literally see a black hole and it has confirmed Einstein’s theory. According to scientists, his theory is now 500 times harder to beat.
Einstein’s robust theory has withstood over 100 years of scrutiny and testing. Yet, researchers continuously test general relativity through physical experiments and astronomical observations to see if it is in line with the ultimate theory of the universe, or the theory of everything. Read more about it on the CNN.
How global heating may make Antarctica’s ice disappear forever
A team of scientists from the Potsdam Institute for Climate Impact Research, Germany has shown how rising temperatures may wipe out all of the ice in Antarctica — a loss that cannot be reversed.
Scientists presented detailed computer simulations that predicted how different levels of warming will affect areas near the south pole.
As oceans and the atmosphere warm up due to greenhouse gas emissions, the ice cap on the south pole will lose mass and eventually become unstable, the study has shown. Antarctica holds more than half of earth’s freshwater.
With average global temperatures rising by 2 degrees Celsius above pre-industrial levels in the past couple of years, melting and accelerated ice flow from Antarctica alone will lead to global sea level rise of 2.5 meters. At a rise of 4 degrees, it will be 6.5 meters and at 6 degrees, the rise will be 12 meters.
Although it will take almost 15,000 years for this melting to happen, global warming today will seal the fate of future generations in our planet. More about it on Live Science.
Flowers are changing colours to adapt to climate change
Climate change is also affecting the world’s flowers. In a new study published this week, scientists have shown that over the past 75 years, rising temperatures and declining ozone layer have led flowers to change colours by altering ultraviolet (UV) pigments in their petals.
Ultraviolet pigments in flowers serve as a kind of sunscreen for plants. Pigments in the flower petals absorb ultraviolet light, preventing harmful radiation from reaching the sensitive cells of plants.
Researchers have previously found that flowers exposed to more UV radiation — such as those growing at higher altitudes or closer to the equator — had more ultraviolet pigments in their petals.
To see whether climate change was affecting UV pigments in plants, scientists looked at plant collections from North America, Europe, and Australia dating all the way back to 1941.
They photographed 1,238 flowers from 42 different species, collected at different times, using a camera which captured changes in UV pigments. The team found that in all locations, UV pigments increased by an average of 2 per cent per year, between 1941 and 2017.
These changes varied depending on the structure of flowers. Flowers with exposed pollen had higher UV-absorbing pigments when ozone levels went down and lower pigments in locations where ozone levels went up.
However, in flowers with pollen concealed within their petals, UV pigments decreased as temperatures went up. Read more here.
Enzyme ‘cocktail’ can quickly degrade single-use plastics
Scientists at the University of Portsmouth have created an enzyme ‘cocktail’ which can ‘digest’ plastic six times faster, providing hope for tackling the menace of single-use plastic waste.
The team had earlier re-engineered a plastic-eating enzyme, PETase, which can attack the hard, crystalline surface of plastic bottles.
They have now found that adding another enzyme to PETase, called MHETase, can speed up the breakdown of plastic. MHETase is a leap forward in finding a solution to tackle plastic waste.
PET, polyethylene terephthalate, is used to make single-use plastic bottles, clothing and carpets. While PET takes hundreds of years to break down in the environment, this new enzyme cocktail can shorten its breakdown period to days.
The enzyme cocktail of PETase and MHETase allows for plastics to be made and reused endlessly, reducing reliance on fossil resources such as oil and gas. More about it on The Guardian.