Understanding Our Cosmos

What we cannot capture with the naked eye is “observed” more accurately by the space telescope “Hubble”, developed through collaboration between NASA and ESA. Since 1990, it has been orbiting Earth at an altitude of 500 kilometers and a speed of eight kilometers per second, in only 97 minutes, delivering new knowledge about galaxies, the expansion of the universe, or even the mass of the Milky Way. In 2021, it will be replaced by the James Webb space telescope. The successor performs its measurements using infrared rays and, thanks to its enormous main mirror measuring 25 square kilometer in size, it can collect up to ten times more light. Equipped with instruments such as an infrared camera, spectrograph and a sensor, the James Webb space telescope is capable of performing even more precise measurements than the legendary Hubble. With the help of the telescope which will be placed roughly 1.5 million kilometers from Earth, scientists aim to study the early existence of the universe, among other topics.

What do we know about our Sun? It continues to be a scientific enigma, similar to the depths of our oceans. In the summer of 2020, however, the space mission “Solar Orbiter”, on behalf of the European Space Agency (ESA), was able to collect images of hitherto unknown regions of the Sun, mere months after its launch. Even though it appeared that the space probe had come extremely close to the star, it had still kept a safe distance of 77 million kilometers – approximately half the distance between the Sun and Earth. The new images are meant to provide insight into how the magnetic field of the dwarf star functions and how solar winds are initiated. Researchers are hopeful that the images will allow predictions about future solar activity. Over the next two years, the orbiter will explore even closer to the Sun, at a distance of 42 million kilometers.

It was only recently that researchers at the NASA Goddard Space Flight Center learned about the secret talents of their satellite “ICESat2”: with the help of its instrument “Atlas”, it is capable of scanning coral reefs 40 meters below the ocean surface. This came as a surprise as this satellite, orbiting at 470 kilometers above Earth, is mainly employed for the observation of climate change. The scan of a coral reef was first discovered in images of the Bikini Atoll in the western Pacific Ocean. The satellite scanned not only the atoll, but also the giant deep reef system. The field of oceanography considers this discovery a major success since the study of coral reefs which are situated at greater depths is extremely difficult. The researchers assume that, based on the ATLAS laser,the structures, as well as the changes of coral reefs, may be understood to an even greater extent.

“The first images that our telescope sent us showed the true beauty of the hidden universe”, said Peter Predehl of the Max Planck Institute for Extra-
terrestrial Physics (MPE) on the occasion of the first publication of photographs taken in late 2019 by the X-ray telescope with the melodious name of “eROSITA”. Every six months, it screens the entire sky and transmits data for the purpose of constructing maps of the sky which depict the universe and its evolution. The astronomers operate on the premise that with the help of “eROSITA” they will find approximately 100,000 galaxy clusters as well as several million active black holes in the centers of these galaxies. Since light from far away galaxies travels for a long time, the telescope can look back in time up to six billion years.