es2625 — Organisation Release
From the Effelsberg Radio Telescope to the ESO Supernova
Extension of the Milky Way Trail to the Research Campus in Garching
8 September 2026
On Wednesday, 9 September, 2026, another external trail panel for the Milky Way Trail at the Effelsberg Radio Telescope will be unveiled at the ESO Supernova Planetarium & Visitor Centre in Garching. The panel, providing information about the galaxy “Sextans A”, is visible from outside the building, and will be presented during the annual conference of the German Astronomical Society. It identifies the ESO Supernova as another branch of the Milky Way Trail, shown at a true-to-scale distance.
The Milky Way Trail is one of three astronomical hiking trails of varying scales at the Effelsberg Radio Telescope. Together, they allow visitors to experience the full range of cosmic distances, ranging from the planets of our solar system to distant galaxies billions of light-years away.
The Milky Way Trail is a project of the Max Planck Institute for Radio Astronomy (MPIfR) and its Effelsberg Radio Observatory. It was established in collaboration with the Freundeskreis Sahrbachtal e.V. as a hiking trail with a total length of four kilometers in the immediate vicinity of the Effelsberg radio telescope.
With a diameter of 100 meters, the radio telescope is the second-largest movable radio telescope in the world. The Milky Way Trail illustrates the distances to various celestial bodies on a scale of 1:10¹⁷ (1:100 quadrillion) — which corresponds to 10,000 light-years per kilometer.
In addition to the 20 core stations in the vicinity of the radio telescope in the Eifel region, there are a number of satellite stations extending the trail, including the Andromeda Galaxy (Messier 31) at the Haus der Astronomie in Heidelberg and the Triangulum Galaxy (Messier 33) at the Institute of Space Systems in Stuttgart.
Now, Sextans A — a member from the outskirts of the Local Group of galaxies surrounding the Milky Way and the Andromeda Galaxy (M31) — has been added. This small, irregular dwarf galaxy lies in the direction of the equatorial constellation Sextans at a distance of about 4.3 million light-years. On the scale of the Milky Way, this corresponds almost exactly to the 430-kilometer straight-line distance between the ESO Supernova in Garching and the Effelsberg radio telescope. Sextans A was discovered in 1942 by the Swiss-American astronomer Fritz Zwicky.
With the addition of this galaxy, there are now five external stations as part of the Milky Way Trail. They also mark the transition from the Milky Way Trail to another astronomical trail at the Effelsberg Radio Telescope: the Galaxy Trail, which uses a scale of 1 : 5 x 10²² (1 : 50 thousand billion billion). On this scale, the Andromeda system—including NGC 205 and Messier 31—is located in the immediate vicinity of the Milky Way, at a distance of just 50 centimeters. Sextans A would be 86 cm away.
The transition between the Planetary Trail and the Milky Way Trail is, in turn, marked by the brightest star in the night sky, Sirius. Sirius lies at a distance of just under nine light-years in the direction of the constellation Canis Major (the Big Dog). On the Milky Way Trail, the two stations “Sirius” and “Sun/Earth” are only 90 cm apart; on the scale of the Planetary Trail, the distance is a whopping 11,000 km.
More information
The Max Planck Institute for Radio Astronomy has established a total of four topical astronomical hiking trails at the site of its 100-meter radio telescope near Bad Münstereifel-Effelsberg. Three of these trails—named the Planetary Trail, the Milky Way Trail, and the Galaxy Trail—cover the entire cosmic distance scale, from the planets of our solar system to distant galaxies several billion light-years away.
The Planetary Trail, on a scale of 1 : 7.7 billion, runs for a total length of 766 m from the visitor parking lot at the radio observatory (panel for dwarf planet Pluto) to the forecourt of the visitor pavilion, where the “Sun” panel is located. The Planetary Trail has a branch location 11,000 km away (equivalent to 8.6 light-years) at the MPIfR’s APEX telescope in the Atacama Desert in Chile, featuring the neighboring star Sirius, the brightest star in the night sky. By contrast, the distance of 310 light-years to Canopus, the second-brightest star in the night sky, would already require a station located at a distance equivalent to that of the Moon.
The Milky Way Trail, on a scale of 1 : 1017 (1 : 100 quadrillion), stretches a total of 4 km (equivalent to 40,000 light-years through our home galaxy) from the outer regions near the Sun to the galactic center. This trail leads from the Burgsahr district of the municipality of Kirchsahr in the Sahrbach Valley to a viewing plateau immediately in front of the 100-meter radio telescope itself. The Milky Way Trail has now four satellite locations—the Andromeda Galaxy M31 at the House of Astronomy in Heidelberg, the galaxy NGC 205 at the Mannheim Planetarium, the Draco Galaxy at the Friedrich-Ebert-Gymnasium in Bonn and the galaxy M33 at the Institute of Space Systems in Stuttgart—each in scaled distance to the Effelsberg Radio Telescope.
The Galaxy Trail, scaled at 1 : 5 x 10²², runs over a total length of 2.7 km (corresponding to just under 14 billion light-years) from our Milky Way to distant galaxies and finally back in time to the Big Bang or the beginning of time. It starts on a forest trail behind the radio telescope and leads to the Martinshütte in the municipality of Kirchsahr, the “barbecue hut at the end of the universe.”
To mark the 50th anniversary of the 100-meter radio telescope in 2021, another hiking trail was added: the “Time Travel Trail,” which chronicles the 50-year history of the Effelsberg Radio Telescope across a total of 20 stations. It winds around the telescope for a length of 5 km, starting right at the visitor pavilion.
Links
- Effelsberg Radio Telescope
- Visitor Programme at Effelsberg Radio Telescope
- Milky Way Trail at Effelsberg
- Planetary Trail at Effelsberg
- Galaxy Trail at Effelsberg
- Time Travel Trail at Effelsberg
- Abstract for the presentation “Sextans A: From the Effelsberg Radio Telescope to the ESO Supernova” at the 2026 AG Meeting in Garching
Contacts
ESO Supernova Planetarium & Besucherzentrum
Garching bei München, Germany
Tel: 08932006900
Email: supernova@eso.org
Dr. Norbert Junkes
Press and Public Outreach Max-Planck-Institut für Radioastronomie
Bonn
Email: njunkes@mpifr-bonn.mpg.de
Dr. Nina Brinkmann
Press and Public Outreach Max-Planck-Institut für Radioastronomie
Bonn
Email: brinkmann@mpifr-bonn.mpg.de
