CALLISTO
- SCI & TECH
News:
Team led by PRL Ahmedabad
finds ozone on Jupiter’s moon Callisto
What's
in the news?
●
An international team of scientists,
including from India, has discovered strong evidence indicating the presence of
ozone on Jupiter’s moon, Callisto, shedding light on the complex chemical
processes taking place on icy celestial bodies in the Solar System.
Key
takeaways:
●
Scientists are currently studying various
celestial bodies in the Solar System that show signs of ozone, suggesting the
existence of stable atmospheric conditions and, by extension, the possibility
of their being able to host life.
●
The detection of sulfur dioxide on
Callisto’s surface has encouraged this team of scientists to conduct
spectroscopic observations to gain a better understanding of the moon’s surface
composition and formation.
Callisto:
●
Callisto is one of Jupiter’s largest moons and the third-largest moon in the Solar System after Ganymede and Titan.
●
Despite being as big as the planet
Mercury, it has less than half as much mass.
Composition:
●
Callisto is primarily composed of water ice, rocky materials, sulphur
dioxide, and some organic compounds. These substances make the moon a
potential candidate for supporting life in the solar system beyond the earth.
Surface
Features:
●
Callisto’s surface is heavily cratered, indicating a long history of being struck by
asteroids and comets.
●
It also lacks the extensive seismic activity seen on some of Jupiter’s
other moons, such as Io and Europa.
●
The presence of relatively few geological
features suggests Callisto’s surface is geologically inactive. In other words,
its surface has likely been relatively stable for a long time. This stability
could be vital to preserve any subsurface ocean or potential habitats beneath
the icy crust.
Go
back to basics:
Jupiter:
●
Jupiter is the fifth planet from the Sun
and is the largest planet in the
solar system – more than twice as massive as all the other planets combined.
●
As a gas giant, Jupiter has no solid surface. Its stripes and swirls are actually
cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen
and helium.
●
Its iconic
Great Red Spot is a giant storm bigger than Earth that has raged for
hundreds of years.
●
Its distance from the sun is 5.2 times the
earth sun distance.
●
It has the shortest day in our solar
system as its day lasts only 10 earth hours; however its year is 12 earth
years.
●
It has 95 moons that are officially recognized by the International
Astronomical Union. Among them the four largest moons are – Io, Europa,
Ganymede, and Callisto.
Ozone:
●
Ozone (O3) is a highly reactive gas composed of three oxygen atoms. It is both a natural and a man-made product that
occurs in the Earth’s upper atmosphere (the stratosphere) and lower atmosphere
(the troposphere). Depending on where it
is in the atmosphere, ozone affects life on Earth in either good or bad ways.
Types
of Ozones:
●
Stratospheric
ozone is formed naturally through the interaction of solar
ultraviolet (UV) radiation with molecular oxygen (O2).
○
Ultraviolet radiation in particular is
harmful to many species (but also useful to some others). Two of its
components, called ultraviolet-B and ultraviolet-C, can damage DNA, trigger
mutations, and increase the risk of skin cancer and cataracts in humans.
●
Tropospheric
or ground-level ozone is formed primarily from photochemical
reactions between two major classes of air pollutants, volatile organic
compounds (VOC) and nitrogen oxides (NOx).