• Educational Activities for Students

    The educational program for children at Thissio Visitor Center

  • Doridis Telescope

    Doridis Telescope

  • WMO certificate
  • ttod_photo01
  • August

    August 2017 | Photo: Theofanis Matsopoulos


    Julius Schmidt, CHARTE DES GEBIRGE DES MONDES, 1878, ΝΟΑ Library

  • simonvouet English2

    Simon Vouet (1590 - 1649), The Muses Urania and Calliope (1634)

    National Gallery of Art, USA

  • Τηλεσκόπιο Αρίσταρχος English

    Aristarchos Telescope, Helmos Observatory

  • Helmos National Geographic English

    Helmos Observatory, Photography: Harry Katzjaeger
    Source: "Top Shots," National Geographic, June 2012

  • Eskimo Nebula NGC2392 English

    Eskimo Nebula (NGC2392), Aristarchos Telescope, Observer: Dr. Ioannis Alikakos (NOA)

    Digital Image Processing: Theofanis Matsopoulos.

  • Μουσείο Γεωαστροφυσικής English

    Geoastrophysics Museum, Thissio

  • Εκπαίδευση στο ΕΑΑ English

    Summer School in Astrophysics

  • Τηλεπισκόπηση-Γή English

    Remote Sensing & Earth Observation

  • Greece from ISS English

    Greece from the International Space Station

    Photography: Paolo Nespoli, ESA astronaut

  • 3D Sun English

    3D Image of the Sun from the Solar Dynamics Observatory (SDO) mission of NASA.

    Source: NASA's Solar Dynamics Observatory

  • Helicorder English

    Analogue seismograph recorder

  • Geothermal English
  • Παλιρροιογραφος English

    Tide-gauge of the Instittute of Geodynamics at Vlyhada, Santorini.

  • Πειραμα Ulusses English
    Recovered  Ocean Bottom Seismometers on board of research vessel in the frame of the ULYSSES scientific program
  • Meteo historic archive english

    The historic archive of NOA/IERSD with recordings of climatic observations dated from the mid-19th century is one of the oldesr sources of climatic information for Eastern Medirranean.

  • Meteo time-series graph English

    The evolution of the average annual temperature in Athens from the mid-19th century until today, according to the records of the historic station NOA/IERSD (Hill Nymphs Thission).

  • Researchers Night 2014

    Pnyx Hill: Citizens observe the night sky through telescopes of NOA

    Researchers Night 2014

  • Researchers Night 2014

    Pnyx Hill: Citizens observe the night sky through telescopes of NOA

    Researchers Night 2014

Space Weather Operational Unit

Adverse conditions in space can cause problems in radio telecommunications, navigation problems, electric power failure, satellites failure, danger to astronaut health. Solar Energetic Particles (SEPs) can penetrate the shield of the geomagnetic field and enter the ionosphere. SEPs penetrate more easily via the areas near the poles of the geomagnetic field than via the equator. Satellites on high-gradient LEO orbits can be vulnerable to SEPs as well as the International Space Station. SEPs can also influence the propagation of signals between Earth and satellites. Protons of 1-100 MeV cause increased ionization which absorbs radio waves at HF and VHF frequency bands, resulting in telecommunication problems and navigation errors. In addition, high-energy protons are dangerous to astronauts' health. SEPs reach at aviation heights and pose a threat for human health since the radiation dose received may be increased. This applies in particular to high latitudes and polar routes. For commercial aviation, there is a risk for 'frequent flyers' and the crew. Therefore, it is necessary to forecast the solar storms and their impacts in a timely manner, which is carried out by the NOA Space Weather Operational Unit.

The HESPERIA REleASE tool provides real-time predictions of 30-50 MeV solar energetic protons in the Geospace. It is based on observations of electrons moving at the speed of light crossing the Sun-Earth distance in a few tens of minutes and being collected by the sentinel SOHO/ACE near-Earth spaceships as precursors of protons arriving 30-90 minutes later. This tool provides more complete predictions than others based solely on observations of solar flares in the visible hemisphere of the Sun. The HESPERIA UMASEP-500 tool provides real-time predictions of events detected on the ground by very high-energy protons (> 500 MeV). The tool provides more timely forecasts than neutron monitors on the ground and is based solely on space data. The forecasts are available through the NOA website (http://www.hesperia.astro.noa.gr). The HESPERIA tools were selected by NASA as a top priority internationally to be included in the emulation of manned missions to the Moon and Mars.

The Space Weather Operational Unit consists of Dr. Olga Malandraki, Senior Researcher of Space Physics, Dr. Georgia Tsiropoula, Research Director, Michalis Karavolos, MSc., PhDc., Software and Satellite Communications Engineer, Nikolaos Milas, Special Technical Scientist and Dimitrios Kokkinis, Informatics and Telecommunications Researcher, BSc, MSc student.

More details can be found at:

Mon Tue Wed Thu Fri Sat Sun

Penteli Visitor Center
Thissio Visitor Center
Educational program on Meteorology
Multiple Events

mainlogo ypourgiodiavgeia logoΓενική Γραμματεία Έρευνας & Τεχνολογίας - General Secretariat of Research & Technology