A graphical representation of ASTRON's rich and exciting history.


Theory of electro-magnetism

James Clerk Maxwell (Edinburgh, June 13, 1831 - Cambridge, November 5, 1879) establishes the theory of electro-magnetism.


First man-made radio waves

Heinrich Hertz (Hamburg, February 22, 1857 - Bonn, January 1, 1894) confirms Maxwell's theory with the generation and reception of the first man-made radio waves.


First radio transmissions across the Atlantic Ocean

Guglielmo Marconi (Bologna, April 25, 1874 - Rome, July 20, 1937) makes the first radio transmissions across the Atlantic Ocean - the modern age of wireless radio communications begins.


Karl Jansky

Karl Jansky (Norman (Oklahoma), October 22, 1905 - Red Bank (New Jersey), February 14, 1950) discovers the first natural cosmic radio emission from the centre of our own Galaxy, the Milky Way.


The birth of high-energy astrophysics

Grote Reber (Chicago, December 22, 1911 - Tasmania, December 20, 2002) begins construction of the first large parabolic antenna, later publishing the first systematic radio surveys of the sky. For the first time, the non-thermal radio universe is revealed and high-energy astrophysics is born.


Neutral hydrogen and the 21 cm wavelength

News of Reber's work reaches Prof. Jan Hendrik Oort in Leiden. Realising that radio emission might permit him to map out the structure of the Milky Way, he asks a young PhD student, Henk van de Hulst to investigate further. Van de Hulst predicts that neutral hydrogen (the most abundant element in the Universe) should be detectable as a radio spectral line at a wavelength of 21 cm.


SRZM officially founded

On 23 April 1949, the forerunner of ASTRON, SRZM (Stichting Radiostraling van Zon en Melkweg / Netherlands Foundation for Radio Astronomy) was officially founded with Prof. Jan Oort (Franeker, April 28, 1900 - Leiden, November 5, 1992) as chairman of the Board, a position he held until his retirement in 1970. SRZM was set up to prepare for the design, construction and operation of the Dwingeloo Telescope.


Mapping out the Milky Way

A young engineer, Lex Muller builds a radio receiver sensitive to radio waves at 21 cm. As predicted earlier by Van de Hulst, Neutral Hydrogen is detected by Muller & Oort using the Würzburg telescope at Kootwijk. With these data, Oort and others map out the spiral structure of the Milky Way.


Opening DRT by HM Queen Juliana

The 25-metre Dwingeloo Telescope (then the largest steerable radio telescope in the world) is opened by Queen Juliana. The telescope maps out the detailed structure of the Milky Way and detects obscured, nearby galaxies Dwingeloo 1 and 2.


Opening WSRT by HM Queen Juliana

The WSRT (Westerbork Synthesis Radio Telescope) is opened by HM Queen Juliana.


Increasing spatial resolution

The WSRT is being expanded to include two new telescopes, increasing the baseline length to 3 km. This doubles the spatial resolution of the telescope. Cooled receivers are also introduced at 6 and 21 cm.


Dark matter in galaxies

The Digital Spectral-Line (DSL) multi-channel correlator is installed, and the first HI line maps are produced of external galaxies. The WSRT provides the best evidence yet for dark matter in galaxies, demonstrating flat rotation curves far beyond the stellar disk.


The European VLBI Network (EVN)

The European VLBI Network (EVN) is established with ASTRON as one of its founding members. The WSRT becomes a major component of the network, building on the first EVN experiment (1976) using the "ODE" network - Onsala (SE), Dwingeloo and Effelsberg (DE).


Instruments for optical and mm-telescopes

The UK-NL research collaboration is signed, leading to ASTRON playing a leading role in the design and construction of instruments for optical telescopes and the new sub-mm James Clerk Maxwell Telescope. This later leads to the establishment of the NOVA Optical/IR Group at ASTRON.


Square Kilometre Array (SKA)

ASTRON is at the forefront of conceiving the original concept of the Square Kilometre Array - this will later emerge as one of the most ambitious global mega-science projects of the 21st century.



The Joint Institute for VLBI in Europe is established, hosted by ASTRON. The EVN Correlator is formally opened in 1998.


Impacting the next generation of radio telescopes

ASTRON embarks on a major new R&D line, developing Aperture Arrays for Radio Astronomy. This has a major impact in the development of several next generation radio telescopes, including LOFAR and the SKA.


Multi-Frequency Front Ends (MFFEs)

A major upgrade of the WSRT is completed. This includes the deployment of the new Multi-Frequency Front Ends (MFFEs). These provide broad-band frequency flexibility from 1 tot 8.4 GHz.



ASTRON's first Phased Array Feed prototype, FARADAY is deployed and tested on the WSRT.


The Netherlands Institute for Radio Astronomy

ASTRON becomes the Netherlands Institute for Radio Astronomy - returning to its original mission: "Making Discoveries in Radio Astronomy Happen!"


Opening LOFAR by HM Queen Beatrix

LOFAR is opened by HM Queen Beatrix.


APERTIF Phased Array Feeds

Opening new building ASTRON

Opening of ASTRON's new building by State Secretary, Drs. Sander Dekker.


Construction SKA telescope

The SKA telescope is under construction.

Latest tweets

Congratulations to our colleague Harish Vedantham who has been awarded a @NWONieuws #Vidi grant for his project e-MAPS! 🥳 With e-MAPS Harish will use @LOFAR to answer the question: what determines the magnetic field of an exoplanet?💫 https://bit.ly/3rekOpA

Congratulations @AstroJoeC on winning the Louise Webster prize with the discovery of Apep, a unique binary star system with the hottest stars in the Universe.

What does the start of construction of @SKAO mean for the Netherlands? Michiel van Haarlem: "we are due to take on work in the following areas: software for the calibration of data and the creation of deep sky images, " read the full interview here: https://bit.ly/3qC6yXA

Another impressive result for LOFAR! An international team of astronomers from @UniLeiden & @mediainaf discovered a galaxy that seems to be wagging it's tail, a tail of 2,5 million light years long! https://bit.ly/2QBTL9W 💫