The National Observatory of Athens is inviting the public to an open three-day observation of celestial objects on June 28-30 at its Visitor Center in Penteli, in celebration of the 150 years of the historic Newall telescope. Astronomy enthusiasts and the general public will have a chance to see the sky through the telescope and also see a presentation by the Planetarium On The Go, a semi-permanent fixed dome structure with seats for the spectators, considered a unique Digital Portable Planetarium. The show is created by Theophanis Matsopoulos, a collaborator of the European Southern Observatory (ESO), and is dedicated to the history and scientific contribution of Newall, once the largest binocular telescopes in the world, which is, to this day, installed and operating in the observatory at Penteli. The National Observatory's observation center at Penteli is operated by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing. The telescope is considered the most impressive instrument of the Observatory of Athens, and was named after Robert Stirling Newall (1812-1889), an amateur astronomer who became a successful entrepreneur in the field of steam engines and telegraphic wires.