Frozen moons, hot stars, the search for favorable conditions for life, exoplanets and receding galaxies, future travel into the past of the Universe, new missions. Sensational attempt to explore it Spacenot only fires the imagination, but also opens up new possibilities in Scientific research and humanity in general.

On the occasion of the World Space Week, which is held annually from 4 to 10 October (to commemorate the launch of the first satellite – Sputnik-1 on October 4, 1954 – and the entry into force of the UN Treaty on Outer Space on October 10, 1967). ), we discuss with Ioannis A. Daglis, President of the Hellenic Space Center and Professor at the University of Athens, the following space issues. Although there are no Chinese walls, we have divided the scientific efforts into three parts: first, those that concern our “home”, planet Earth. Secondly, those that manifest themselves in our solar system. Thirdly, those that concern the distant Cosmos.

Travel to distant celestial bodies can be tempting, but about 90% of the turnover in space is in the vicinity of the Earth. “Space is a space for observing our planet and developing a number of essential services that affect and facilitate our daily lives: telecommunications, navigation, weather forecasts. The economic activity of countries and companies is high. There are already more than 4,500 satellites in Earth’s orbit, as well as about 2,500 inactive ones. Big technological steps have been taken, but we are looking for solutions for further improvements.”

satellite photos

Some examples: In the context of meeting our national needs, the Hellenic Space Center (ELKED) is looking for solutions that will give us satellite images with better resolution than the 10×10 meters offered by the European Copernicus Earth Observation System. “This is good, but not enough for our national needs. ELKED is planning a national satellite surveillance program in 3×3 meters, which gives a tenfold improvement in resolution,” says Mr. Daglis. “In addition, observation satellites are located relatively low, at an altitude of 500-2000 km, in order to have good spatial resolution. But because they are constantly revolving around the Earth, they do not provide continuous coverage like geostationary satellites, which have an altitude of 36,000 km and constantly remain over the same area of ​​​​our planet. Obviously, the resolution of images from this height is much worse. The space industry is trying to combine the information we get from these two types of orbits,” adds the president of ELKED.

Confusion in space

New challenges, but also dangers for our near space, will create a new period … of private invasion, when private companies plan to launch numerous fleets of satellites. “Continued launches in the long term will put pressure on the space ecosystem. There will be overloads with the risk of collision of ships, which will cause space debris, which, in turn, will cause serious damage or even destroy other satellites. This issue needs to be regulated and addressed. Global agreements at the UN level on the beneficial uses of space for all take a lot of time and effort to update. A good example has already been set by the European Space Agency (ESA), which requires for any launch proposal a general plan to complete the mission and “decommission” the spacecraft,” says Mr. Daglis.

Telecommunications, navigation, meteorology. More than 4,500 satellites revolve around the Earth, as well as about 2,500 inactive ones.

higher goals

At the second level, inside the solar system, higher goals are set. “A key focus is the exploration of a semi-known world such as Mars, which is believed to be the only celestial body that, at least in theory, could have the capacity to host humans. Of course, this is a very remote case. The second direction is aimed at the icy moons of Jupiter and Saturn, which are of great astrobiological interest, since some kind of life may be hiding under their icy surface. This is something that we cannot exclude, for example, on Europa or Enceladus, since on Earth we have also discovered life at great depths in the oceans, in conditions where this was previously considered impossible, ”the professor notes.

ESA’s JUICE (Jupiter Icy Moons Explorer) will be launched in 2023, a truly “savory” mission that aims to make detailed observations of Jupiter, the gas giant planet, and its three large moons (Ganymede, Callisto and Europa), which are said to be that the water is under the ice. “Measurements of the magnetic field on Europa can only be justified because of the rotational motion of the salt water. Jets of water have been recorded on Saturn’s moon Enceladus. NASA is already studying future missions to drill into the surface ice of Europe,” explains Mr. Daglis.

space meteorology

Another aspect of the search in our solar system is a better understanding of the Sun-Earth system and the interactions between them. “We have taken many steps, but we want to go even further. For example, to be able to predict space weather, space storms like those on the surface of the Earth, which will greatly help the safety of missions and satellites,” notes the Greek professor.

In the vast expanse beyond the solar system, the driving force behind human exploration is primarily scientific questions about our world. “Our spacecraft has reached a very, very small part of the universe. We were surprised at how many old galaxies we found. The universe is much older than we thought. Information comes to us through photons, from the entire spectrum of electromagnetic radiation, and more recently from gravitational waves. Today we are getting sharper and clearer images of the heavenly bodies, farther and farther, farther and farther back in time, into the past. The James Webb telescope also helps in this, which for the first time was able to distinguish the atmospheres of exoplanets, that is, planets outside the solar system, ”says Mr. Daglis.

From earth to moon

Last question, first stop. Why are they preparing a mission to the moon again? “Firstly, it is easier to launch heavier spacecraft from the Moon to Mars or somewhere else. There are also valuable mineral resources on the Moon, such as rare earth elements. And, of course, there is always the charm of a human walk on the moon…”.

stargazing

If you and your children want to get to know the Great Cosmonaut School, then you can visit the event organized today, from 17:00 to 22:00, by the Department of Astrophysics, Astronomy and Engineering of the Faculty of Physics of the EKPA in the context of the World Space Week at the Faculty of Physics of the Zografo campus ( the entrance is free). At the event, Associate Professor Kalliopi Dasira will talk about the James Webb Space Telescope, as well as a tour of the facilities of the Gerostathopoulios University Observatory and observation of the night sky with the observatory’s telescope, as well as with portable telescopes from the roof of the building. Read more at https://bit.ly/3Ciw9Lt.