EROSITA Logo.png
ManufacturerMax Planck Institute for Extraterrestrial Physics
Instrument typeWolter
FunctionX-ray all-sky survey
Mission duration> 7 years [1]
Mass810 kg (1,790 lb) [1]
Dimensions1.3 m × 2.6 m [1]
Number launched7 mirror modules
Power consumption550 W [1]
Resolution15 arcsec (at 1.5 keV)
Spectral bandX-rays, 0.2 - 10 keV
Host spacecraft
Operator Russia, Russian Space Research Institute
 Germany, German Aerospace Center
Launch date13 July 2019[2]
RocketProton-M [3]
Launch siteBaikonur 81/24
OrbitSecond Lagrange point (L2)

eROSITA is an X-ray instrument built by the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany. It is part of the Russian-German Spektr-RG space observatory, which also carries the Russian telescope ART-XC. It was launched by Roscosmos on 13 July 2019 from Baikonur, and deployed in a 6-month halo orbit around the second Lagrange point (L2).[3]


eROSITA overview animation

eROSITA was originally studied by ESA for the International Space Station, and it was concluded in 2005 that its accommodation on a dedicated free flyer would provide significantly improved scientific output.[4] The eROSITA telescopes are based on the design of the ABRIXAS observatory launched in April 1999, whose battery was accidentally overcharged and destroyed three days after the mission started.[4]

eROSITA is imaging the entire sky in the X-ray band over a 7-year period. The eROSITA all-sky survey (eRASS) is first image of the entire sky in the 2-10 keV band. In the 0.3-2 keV band, it is expected to be 25 times more sensitive than the pioneering ROSAT mission of the 1990s, and will effectively supersede it.[5] eROSITA is expected to detect 100,000 galaxy clusters, 3 million active galactic nuclei and 700,000 stars in the Milky Way. The primary science goal is to measure dark energy through the structure and history of the Universe traced by galaxy clusters.

eROSITA achieved first light 17 October 2019,[6] and completed its first all-sky survey on June 11, 2020.[7]


The telescope consists of seven identical Wolter-type mirror modules with 54 nested gold-coated mirrors. The mirrors are arranged to collect the high-energy X-ray photons and guide them to the eROSITA X-ray sensitive cameras. The cameras were also custom-built at MPE, with X-ray CCDs manufactured from high-purity silicon. For optimum performance, the cameras are cooled to −90 °C (−130 °F; 183 K).[8]


Instruments on the Spektr-RG observatory
Organisation Max Planck Institute for Extraterrestrial Physics IKI / VNIIEF
Telescope type Wolter Wolter
Wavelength X-ray X-ray
Mass 810 kg 350 kg
Sensitivity range 0.3 - 10 keV 6 - 30 keV
View angle 1 degree 30 minutes
Angular resolution 15 seconds 45 seconds
Sensor area 2,400 cm2/ 1 keV 450 cm2/ 8 keV


eROSITA was developed at the Max Planck Institute for Extraterrestrial Physics in collaboration with institutes in Bamberg, Hamburg, Potsdam und Tübingen. The instrument principal investigator is Peter Predehl. The project scientist is Andrea Merloni. The German eROSITA consortium has members from institutes all across Germany, but also from international institutes, and has established collaborations with ground-based telescopes for follow-up observations of the millions of sources that will be detected by eROSITA.

German eROSITA consortium meeting in Potsdam, March 4-7, 2019

Science results

First science verification results were released on October 22, 2019,[9] including high-resolution spectra of Supernova 1987a, images of the Large Magellanic Cloud and galaxy clusters, as well as light curves of a highly variable Active Galactic Nuclei.

Interacting galaxy clusters A3391 & A3395 with eROSITA

The first all-sky survey was completed on June 11, 2020,[10] cataloging 1.1 million sources, including mostly Active Galactic Nuclei (77%), stars with strong, magnetically active hot coronae (20%) and clusters of galaxies (2%), but also bright X-ray binaries, supernova remnants, extended star-forming regions as well as transients such as Gamma-Ray Bursts.[11] The map includes extended features of the Milky Way, including mushroom-like bubbles and absorbing galactic gas in the disk (blue).[12]

eROSITA all-sky survey image


  1. ^ a b c d e eROSITA Technical Performance. Max Planck Institute for Extraterrestrial Physics. Accessed on 14 June 2019.
  2. ^ "Новости. О пуске ракеты-носителя "Протон-М"". Retrieved 12 July 2019.
  3. ^ a b Zak, Anatoly (16 April 2016). "Spektr-RG to expand horizons of X-ray astronomy". Russian Space Web. Retrieved 16 September 2016.
  4. ^ a b "Spectrum-RG/eRosita/Lobster mission definition document". Russian Space Research Institute. 2005-10-30. Retrieved 2011-02-04.
  5. ^ Castelvecchi, Davide (11 June 2019). "Space telescope to chart first map of the Universe in high-energy X-rays". Nature. Retrieved 14 June 2019.
  6. ^
  7. ^
  8. ^ Merloni A, Predehl P, Becker W, Böhringer H, Boller T, Brunner H, Brusa M, Dennerl K, Freyberg M, Friedrich P, Georgakakis A, Haberl F, Hasinger G, Meidinger N, Mohr J, Nandra K, Rau A, Reiprich TH, Robrade J, Salvato M, Santangelo A, Sasaki M, Schwope A, Wilms J, et al. (German eROSITA Consortium) (2012-09-20). "eROSITA Science Book: Mapping the Structure of the Energetic Universe". arXiv:1209.3114 [astro-ph.CO].
  9. ^ Predehl, Peter (11 June 2019). "Revealing the Beauty of the Hidden Universe: eROSITA sees first light". Max Planck Institute for Extraterrestrial Physics. Retrieved 19 June 2020.
  10. ^ Merloni, Andrea (19 June 2020). "Our deepest view of the X-ray sky". Max Planck Institute for Extraterrestrial Physics. Retrieved 19 June 2020.
  11. ^ Merloni, Andrea (19 June 2020). "Presskit for the eROSITA First All-Sky Survey". Max Planck Institute for Extraterrestrial Physics. Retrieved 19 June 2020.
  12. ^ Amos, Jonathan (19 June 2020). "Breathtaking new map of the X-ray Universe". BBC News. Retrieved 19 June 2020.

External links

  • Home page of eROSITA
  • Nature news article
  • eROSITA science book
  • Simulations of the expected X-ray sky
  • Project news on Twitter
  • Video animation