ANtarctic Impulsive Transient Antenna


  • In a significant breakthrough, a team of researchers have succeeded in finding "a fountain of high-energy particles erupting from the ice" in Antarctica which according to the researchers could be proof of a parallel universe.
  • ANtarctic Impulsive Transient Antenna or ANITA - an experiment maintained by researchers at NASA - has suddenly come into the limelight as the cosmic-ray shower that is key to the new discovery was a part of NASA's ANITA and Ice Cube experiment taking place in Antarctica.

What is ANITA?

  • Designed by world's premier space agency NASA, the ANITA instrument is a radio telescope which is used to detect ultra-high energy cosmic-ray neutrinos from a scientific balloon flying over Antarctica.
  • It is the first NASA observatory for neutrinos of any kind.
  • It involves an array of radio antennas attached to a helium balloon which flies over the Antarctic ice sheet at 37,000 meters.
  • To get a gauge of exactly how high is that, know that commercial flights fly almost a fourth of that height.
  • The height is important here to shut out all other "noises" so that the ANITA antennas can "listen" to the cosmos and detect high-energy particles, known as neutrinos, which constantly bombard the planet.
  • ANITA succeeded in detecting the 'fountain' of high-energy particles in 2006 and 2014 but the researchers initially thought them as background noise or glitches.
Different ways signals can reach ANITA as the device floats over Antarctica hanging from its balloon

How does ANITA detect Neutrinos?

  • The ANITA instrument <detects these ultra-high energy neutrinos by use of the Askaryan effect.
  • This effect predicts the production of a coherent radio emission from the cascade of particles produced in a high-energy particle interaction.
  • In order to detect this radio emission (Askaryan pulses) we need a radio transparent medium for the interaction to occur in - and lots of it since these interactions is rare.

Experimental Time Frame

  • ANITA-I launched from McMurdo, Antarctica in the summer of 2006–07.
  • ANITA-II, a modified instrument with 40 antennas, launched from McMurdo Station in the summer of 2008–2009.
  • ANITA-III, launched in December 2014.
  • ANITA-IV launched in December 2016, with a lighter overall build, tunable notch filters and an improved trigger system.

Neutrinos

  • A neutrino is a subatomic particle that is very similar to an electron, but has no electrical charge and a very small mass, which might even be zero.
  • Neutrinos are one of the most abundant particles in the universe.
  • These are affected only by a "weak" sub-atomic force of much shorter range than electromagnetism, and are therefore able to pass through great distances in matter without being affected by it.
  • Natural sources of neutrinos include the radioactive decay of primordial elements within the earth, which generate a large flux of low-energy electron-anti-neutrinos. 

Askaryan Effect

  • It is the phenomenon whereby a particle traveling faster than the phase velocity of light in a dense dielectric (such as salt, ice or the lunar regolith) produces a shower of secondary charged particles which contain a charge anisotropy and thus emits a cone of coherent radiation in the radio or microwave part of the electromagnetic spectrum.
  • It is similar to the Cherenkov radiation.
  • It is named after Gurgen Askaryan, a Soviet-Armenian physicist who postulated it in 1962.



Agent Orange


Why is it in News?

The US has launched a multi-million dollar clean-up operation at an air base in Vietnam it used to store the notorious chemical Agent Orange.

Brief Background:

  • During the Vietnamese war in 1960s, guerrillas supported by the Communist Party used to attack the US forces and hide in the canopy cover of plants and trees. This tactic created Pandora’s Box of problem for the US forces.
  • To counter this, the US government used a herbicide called as ‘Agent Orange’ to destroy the plants and trees cover so that guerrillas can be taken head on.
  • This operation by the US force was part of ‘Operation Ranch Hand’.
  • This chemical was not only carcinogenic but was accompanied with many diseases related to respiratory tracts, nervous system etc.

Chemical Composition of Agent Orange:

  • The active ingredient of Agent Orange is combination of 2,4-dichlorophenoxyacetic acid (also called as 2,4-D) and 2,4,5-Trichlorophenoxyacetic acid(also called as 2,4,5-T).
  • Agent Orange contains dioxin, which is one of the most toxic chemicals known to man and has been linked to increased rates of cancers and birth defects.


Source: BBC

Cassini-Huygens Mission


Why is it in News?

Data and images as obtained from Cassini-Huygens Mission have revealed that lakes of Titan (moon of Saturn) were filled with liquid hydrocarbons.

About Cassini-Huygens Mission:

  • Cassini–Huygens was an unmanned spacecraft sent to the planet Saturn.
  • It was launched by NASA in collaboration with European Space Agency and Italian Space Agency in 1997.
  • Cassini was the fourth space probe to visit Saturn and the first to enter orbit.
  • This mission was launched to study Saturn, its ring system and more importantly its Moon Titan.
  • The mission has two components:-
  • a)Cassini Component: Cassini was an orbiter which was launched to study Saturn and its atmosphere.
  • b)Huygens Component: Huygens was a probe that landed on Saturn’s largest Moon Titan in 2005.
  • The mission ended in 2017 when Cassini spacecraft plunged into Saturn itself.

Key Findings from the Data & Images of Titan:

  • Lakes on earth are filled with liquid water but lakes of Titan are filled with liquid methane and ethane.
  • Scientists have analyzed that hydrocarbon reserves in lakes of Titan are almost 400 times more than the hydrocarbon reserves present on the Earth.

How come Methane & Ethane is present in Liquid form on Titan?

Methane and Ethane on Earth is present in gaseous form but on Titan it is present in liquid form as the climate is extremely cold on Titan.


Source: TH

SpaceX


Why is it in News?

Due to strong winds in the upper atmosphere, SpaceX has postponed its first commercial flight.

About SpaceX:

  • It was founded by Elon Musk in 2002.
  • It has developed by Falcon 1 & Falcon 9 which are reusable launch vehicles.
  • In 2018, it became the first privately funded company to launch object into the solar orbit
  • In 2012, it became the first privately funded company to send a spacecraft to the International Space Station.
  • In 2017, it became the first privately funded company to have its reusable orbital Rocket(Falcon 9)


Source: TH, IE, space.com