IAS Gyan

Daily News Analysis


2nd February, 2024 Science and Technology


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  • The German eROSITA consortium has released the data for its share of the first all-sky survey by the soft X-ray imaging telescope flying aboard the Spectrum-RG (SRG) satellite.
  • With about 900,000 distinct sources, the first eROSITA All-Sky Survey (eRASS1) has yielded the largest X-ray catalog ever published.
  • The work is published in the journal Astronomy & Astrophysics.


  • eROSITA is an X-ray instrument developed by the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany.
  • It is part of the Russian–German Spektr-RG space observatory, launched by Roscosmos on July 13, 2019.
  • eROSITA is designed to observe the entire sky in the X-ray band, providing valuable data on a wide range of celestial objects.

Mission Overview

  • Launched: July 13, 2019, from Baikonur.
  • Deployment: Placed in a 6-month halo orbit around the second Lagrange point (L2).
  • Original Design: Initially intended for the International Space Station (ESA), later adapted for the dedicated Spektr-RG mission.
  • Data Collection: Began in October 2019.
  • Breakdown: Data collection halted on February 26, 2022, due to the breakdown of institutional cooperation between Germany and Russia after the invasion of Ukraine.

Scientific Goals

  • Sky Survey: Intended to image the entire sky in the 2-10 keV X-ray band.
  • Sensitivity: Expected to be 25 times more sensitive than the ROSAT mission in the 0.3-2 keV band.
  • Targets: Aims to detect 100,000 galaxy clusters, 3 million active galactic nuclei, and 700,000 stars in the Milky Way.
  • Dark Energy Study: Primary science goal is to measure dark energy through the structure and history of the Universe traced by galaxy clusters.

Instruments on Spektr-RG

  • eROSITA: X-ray telescope developed by Max Planck Institute.
  • ART-XC: X-ray telescope developed by IKI / VNIIEF (Russia).


Q. What is eROSITA?

a) Lunar Rover developed by NASA

b) X-ray instrument for space observation

c) Satellite for weather monitoring

d) Mars exploration spacecraft

Answer: b)