Essential Facts (Prelims): 13th January 2019


Solar plasma

  • Plasma particles from the solar wind make their way into the Moon’s night side, filling up the wake region, long thought to be devoid of plasma particles.
  • This has significance in understanding bodies like the Moon which do not have global magnetic fields.
  • Plasma environment of the Moon is generated mainly by its interaction with the solar plasma wind flowing towards it from the Sun.
  • This plasma wind consists of charged particles such as protons and is partly absorbed by the side of the Moon facing the sun.
  • The rest of the solar plasma wind incident on the Moon flows around it, but leaves a wake (a void) on the side not facing the sun (the night-side of the Moon).
  • Earlier, it was believed that this wake was devoid of any particles. But recent Moon missions such as Chandrayaan-1, Kaguya, Chang’e-1 and Artemis have found evidence of refilling of near lunar wake (heights of 100 km to 200 km above the lunar surface on the night side) with solar wind protons.
  • Unlike the Earth, the Moon has no global magnetic field originating from a magnetized core. It has weak crustal fields that are too small to shield it globally from charged solar plasma particles incident on it.
  • At some regions the crustal fields are quite strong and these are known as magnetic anomalies. The plasma particles scatter off these anomalous crustal fields.
  • The interaction between the Moon and the solar plasma is a topic of interest now because understanding it can help us study any celestial body which has no atmosphere or global magnetic field, such as asteroids and some planetary satellites.


  • Scientists have repurposed the gene-editing tool CRISPR to study which genes are targeted by particular antibiotics, providing clues on how to improve existing antibiotics or develop new ones.
  • Resistance to current antibiotics by disease-causing pathogens is a global problem. The technique, known as Mobile-CRISPRi, allows scientists to screen for antibiotic function in a wide range of pathogenic bacteria.

Wandering pole

  • Rapid shifts in the Earth’s north magnetic pole are forcing researchers to make an unprecedented early update to a model that helps navigation by ships, planes and submarines in the Arctic.
  • The wandering pole is driven by unpredictable changes in liquid iron deep inside the Earth. It’s moving at about 50 km (30 miles) a year. It didn’t move much between 1900 and 1980 but it’s really accelerated in the past 40 years.
  • Scientists must periodically update the World Magnetic Model to map this process, and the most recent version — produced in 2015 — was intended to last until 2020.
  • However, the magnetic field has been changing so quickly and erratically that researchers realised drastic steps were needed.
  • The changes are essential as the system is used by aircraft, ships and even smartphones.


  • Ladakh is set to host the world’s largest single-location solar photo-voltaic plant.
  • The Ladakh project will be located at Hanle-Khaldo in Nyoma, a strategically important area 254km from Leh.

Legacy person

A legacy person is someone who figures in a set of pre-1971 documents such as the 1951 NRC and voters’ lists up to 1971, who an applicant can trace his or her lineage to.