A Rare Transit of Mercury

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November 11-Mercury skipped the vast, glaring face of the sun. A rare celestial transit. Planet Mercury Facts, Nearly tidally locked to the Sun. Known as a gravitational lock also. Rotation of the planet has been slowed down to match its orbit around the Sun.

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  • Second densest planet.
  • One of the five planets-visible to the naked eye.
  • No moons or rings.
  • Second hottest planet.
  • A very thin atmosphere.
  • Mercury՚s orbit important in proving Albert Einstein՚s theory of General Relativity.
  • Only Two spacecrafts which visited Mercury: Mariner 10 and Messenger

Star Formation in Jellyfish Galaxies (Astrosat View)

  • Jelly fish galaxy, JW100
  • Using Ultraviolet Imaging Telescope.
  • Galaxy
  • A huge collection of gas
  • Dust
  • Billions of stars
  • Solar Systems
  • Held together by gravity
  • Milky Way (Galaxy) - a supermassive black hole in the middle.
  • Three types- Elliptical, Spiral and Irregular
  • Tunning fork diagram-Two of the galaxy types are further divided and classified into a system.
  • Spiral galaxies
  • Most common type in the universe.
  • Milky Way is a spiral-close by Andromeda Galaxy.
  • Spirals-large rotating disks of stars and nebulae, a shell of dark matter surrounding.
  • Galactic bulge-Central bright region
  • Elliptical Galaxies
  • Roughly egg-shaped (ellipsoidal or ovoid) .
  • Largely in galaxy clusters and smaller compact groups.
  • Contains older, low-mass stars, and lack a great deal of star-making gas and dust clouds.
  • Little new star formation.
  • Messier 87- An elliptical galaxy.
  • Irregular Galaxies
  • Irregular in shape.
  • Small Magellanic Cloud-Can be seen from the Earth.
  • Cartosat-3 Launched
  • Third generation agile satellite.
  • Overall mass of over 1,600 kilograms.
  • High-resolution imaging capabilities.
  • Launched by ISRO along with 13 other commercial nanosatellites.
  • Will replace the IRS series.
  • A panchromatic resolution of 0.25 metres
  • Satellite imaging with the highest resolution.
  • The increased user demand for large-scale urban planning.
  • Rural resource and infrastructure development.
  • Coastal land use and land cover.
  • Mission-5 years.

Discovery of Mount Black Hole

  • Black hole 70 times bigger than Sun.
  • Located 15,000 light-years from Earth.
  • Named LB-1 by the researchers at National Astronomical Observatory of China.
  • Black Hole
  • Light cannot get out.
  • Gravity is very strong.
  • People cannot see because of no light.
  • Invisible
  • Space telescopes with special tools-Find black holes
  • Sagittarius A⚹-Black hole at the centre of the Milky Way galaxy.
  • Voyagers 2
  • Voyager 2-Second spacecraft to enter interstellar space.
  • Dec 10,2018- Spacecraft joined its twin-Voyager 1.
  • Voyager 1 and 2-Designed to take advantage of a rare planetary alignment to study the outer solar system up close.
  • Voyager-2 targeted Jupiter, Saturn, Uranus and Neptune.
  • Voyager-2- Designed to find and study the edge of our solar system.
  • Heliopause
  • Beginning of interstellar space.
  • Sun՚s constant flow of material and magnetic field stop affecting its surroundings.

Carbon Offsetting and Carbon Credits

  • Carbon Offsetting- helps a country reach its own emissions reduction targets.
  • Involves funding emission reductions in another country.
  • Companies use carbon credits to offset their emissions.
  • UN՚s Clean Development Mechanism
  • Set up under the 1997 Kyoto Protocol.
  • 190 countries agreed country-by-country emission reduction targets.
  • To help fund emission reduction projects in developing countries.
  • To provide offset credits to the developed world.
  • Help meet Kyoto targets.
  • Carbon Credit
  • A permit or certificate.
  • A holder or a company is allowed to emit carbon dioxide or other greenhouse gases.
  • Limits the emission to a mass equivalent to one ton of carbon dioxide.
  • Ultimate aim- to reduce the emission of greenhouse gases into the atmosphere.


China Rolls Out 5G Services

  • Three major state telecoms rolled out 5G wireless technology.
  • China races to narrow its technology gap with the US.
  • A neck to neck trade war between the two.


  • Simply stands for fifth generation.
  • Refers to the next and newest mobile wireless standard.
  • Based on the IEEE 802.11ac standard of broadband technology.
  • Formal standard-Yet to be set.
  • Next Generation Mobile Network՚s 5G white paper.
  • 5 G must be based on
  • User experience
  • System performance
  • Enhanced services
  • Business models and management & operations.
  • Groupe Speciale Mobile Association (GSMA) -8 Criteria
  • One to 10Gbps connections to end points in the field.
  • One millisecond end-to-end round trip delay.
  • (Perception of) 99.999 % availability.
  • (Perception of) 100 % coverage.
  • 1000x bandwidth per unit area.
  • 10 to 100 x numbers of connected devices.
  • 90 % reduction in network energy usage.
  • Up to ten-year battery life for low power, machine-type devices.


  • Google Warning
  • 500 users in India of government-backed phishing attacks.


  • Fraudulent use of electronic communications.
  • To deceive and take advantage of users.
  • To gain sensitive, confidential information.
  • Usernames, passwords, credit card information, network credentials etc.
  • Cyber attackers use social engineering to manipulate victims into performing specific actions like clicking on a malicious link or attachment.
  • Willfully divulging confidential information.
  • Individuals and Organizations both are at risk.
  • Any kind of personal or organizational data can be valuable.
  • To commit fraud or access an organization՚s network.
  • Phishing scams can target organizational data.
  • To support espionage efforts.
  • State-backed spying on opposition groups.


  • Means to infiltrate smartphones.
  • Works on three things- collect historic data on device, continuously monitor activity and transmit this data to a third party.
  • Can penetrate Symbian and BlackBerry-based devices other than Android and iOS systems.
  • Malware can infect devices via phishing text messages.
  • Trick users into clicking a particular link.
  • Over-the-air update system and more.
  • WhatsApp- Used vulnerability in the app that allowed infection through missed video calls.
  • Spyware completes the process in the background out of the user՚s notice.
  • Pegasus doesn՚t require the user՚s attention.
  • Spyware is so dangerous and popular amongst security contractors.

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