Artist's impression of the ROSAT satellite in space.
A few days before re-entering Earth's atmosphere, the German X-ray research satellite ROSAT was targeted by the Tracking and Imaging RAdar (TIRA) at the Fraunhofer Institute for High Frequency Physics and Radar Techniques in Wachtberg, near Bonn. TIRA is part of a global network of monitoring stations that collected data about ROSAT. From this data, the orbit was determined and images were produced. This example, acquired on October 20, 2011, clearly shows the antenna mast of the satellite.
This still from an animation by Analytical Graphics, Inc., depicts the re-entry of Germany's defunct ROSAT satellite in October 2011.
On Oct. 14, 2011, astrophotographer Marco Langbroek of the Netherlands caught this view of the German satellite ROSAT, which is expected to fall to Earth in October 2011. He said: "I just observed the satellite again, in even deeper twilight. It is moving very fast, quite a spectacular view."
This image, obtained with ROSAT during its all-sky survey in 1990 and 1991, shows the entire sky in X-rays. In this image, our Milky Way lies at the level of the equator, where supernovae remnants (for example in the Vela constellation on the right half of the image) and X-ray binaries can be seen. The various colours indicate the different energy strengths of the X-ray radiation.
This exclusive image was made by Ralf Vandebergh, who said: "It is false-color to increase certain visible contrasts. A very special detail visible is the shadow of the body (the telescope) on the solar panels! You can see the angle with the sun and the observer (me) as ROSAT passed not overhead but [at] 51.4 degrees northern latitude. This is a very difficult observation as the object is very small."
This exclusive image was made by Ralf Vandebergh for SPACE.com, who said: "It is false-color to increase certain visible contrasts. A very special detail visible is the shadow of the body (the telescope) on the solar panels! You can see the angle with the sun and the observer (me) as ROSAT passed not overhead but [at] 51.4 degrees northern latitude. This is a very difficult observation as the object is very small."
A sample representation based on three consecutive orbits of ROSAT around the Earth. Each of these orbits has a duration of about 90 minutes. The path of one orbit to another gradually changes above Earth's surface. This image shows ROSAT on April 12, 2011.
The ROSAT satellite undergoing tests in the space simulation chamber at Dornier.
The ROSAT system of mirrors comprises four nesting Wolter mirrors with a focal length of 2.4 meters. Each of the ring-shaped mirrors measures 50 centimeters in length, and the largest has a diameter of 84 centimeters. The mirrors, manufactured by Carl Zeiss, possess the smoothest mirror surfaces ever produced. This photograph depicts the mirror system from the 'viewpoint' of inbound X-ray radiation.
This X-ray satellite was launched from Cape Canaveral in Florida on June 1, 1990, on a Delta II rocket, property of NASA. Originally, the plan was to put Rosat into Earth orbit using a US space shuttle. Following the explosion of Challenger in 1986 (when ROSAT was under construction), it was decided to launch the X-ray satellite into orbit on a rocket.
Rosat is equipped with three detectors. Two of these are identical four-wire proportional counters known as Position Sensitive Proportional Counters detectors (PSPC), developed by the Max Planck Institute of Extraterrestrial Physics (MPE) in Garching, near Munich. The PSPC detector provides a wide field of view and a level of energy resolution that enables it to distinguish four colors.
In May 1995, ROSAT obtained this image of a galaxy cluster with a diameter of 10 million light years. This is just one of more than 200,000 ROSAT sources. The colours indicate the temperatures of the hot gas in the galactic nebula, as derived from ROSAT imaging data. In the regions at the centre of this image, the temperatures may rise to more than ten million degrees Celsius. Superimposed is an optical image (black) showing the superimposed individual galaxies.
The longest ROSAT observation of a specifically selected area of the sky lasted two weeks, and showed that more than 80 percent of cosmic X-ray background radiation is comprised of individual sources. Most of these sources are objects known as quasars, which are very energetic and distant active galactic nuclei with black holes in their centres.
This diagram shows solar activity from 1995 to 2020. The monthly average figures for the relative number of sunspots based on the frequency of sunspot occurrence are depicted. The 11-year activity cycle can be seen clearly here. The next 'maximum level' of solar activity is expected in about 2013, and is predicted to be substantially less powerful than its predecessor.
