Terra-Astronomy
We use terrestrial archives (historical written, oral, and drawings as well as radioisotopes on Earth) to study effects of variable solar activity and nearby stellar explosions on Earth: The long-term irradiance variation of our Sun affects atmosphere, climate, and biosphere of the Earth. Nearby explosive events (like strong flares on our Sun, normal stars, and neutron stars, novae and supernovae, as well as gamma-ray bursts) deposit high-energy emission into the Earth atmosphere. Both, the steady flux of Galactic cosmic rays into the Solar system – modulated by the variable solar wind – and the transient flux from high-energy events generate radioisotopes (like 10Be, 14C) on Earth, so that they can be used to study such effects.
One can reconstruct solar activity and can identify relevant stellar explosions over the last few millenia using both radioisotopes on Earth and historical observational reports about aurorae, comets, sunspots, (super-)novae, etc. from all civilizations on Earth: While European and Eastern Asian reports have been studied already, historical documents from Arabia were not considered much, yet. Terra-Astronomy is universal and trans-disciplinary. European, Byzantine, and East Asian reports date back up to 2000–3000 years. One can try to use Babylonian, Assyrian, Hithite, and Egyptian reports to go back even further.
The ultimate goals are (i) to understand solar activity variations well enough for sufficiently precise expectations of solar activity for the next few years and decades (space weather and Earth climate), and (ii) to evaluate possible effects of nearby explosions on climate and evolution on Earth in the past.
In an additional, complimentary project part, we investigate the pre-historic epoch with neutron stars and runaway stars – both the last 100,000 years with supernova remnants and even the last few million years.
The Earth is truely a celestial body, and it is subject to variable emission from the Sun and from many other celestial objects.
In comparison to similar fields...
- Terra-Astronomy is also a study of space weather: it covers several millennia and uses historical archives, but it includes studying space weather (solar storms in the near Earth environment like the low-Earth orbits of satellites and astronauts) on all time-scales;
- it is not just a study of catastrophic events (like asteroids hitting Earth), but instead studies variations of emission on all time-scales, and it includes explosive events;
- it is a study of solar-terrestrial relations and extends this subject to all other relevant astrophysical phenomena;
- it is not just a natural science, but a trans-displiplinary endeavour with science, humanities, and arts, e.g. the interpretation of celestial observations and their impact on history;
- it is applied historical astronomy with the reconstruction of naked-eye astronomy, and also involves terrestrial radioisotope archives and new current astronomical (follow-up) observations; and
- it is not only about history of science, because we use historical archives for advancing certain fields of astrophysics – yet, we also study the history of astronomy.
Astronomy is one of very few scientific disciplines, where historical observations and data – as reported in manuscripts of previous centuries and millennia (partly also oral tradition, cave paintings and drawings) – can be used not only to study the history of this field (and to constrain chronologies in general), but also to obtain new results at the forefront of actual astrophysical science: Solar activity, space weather, supernovae, comets, etc.
Our project is feasible for the last few millenia, namely since reports were written and preserved.
This project has a strong potential for public awareness on our dependance on external factors and worldwide citizen science with non-professional historians and high-school students searching for more reports about celestial events in their local chronicles. Terra-Astronomy is highly trans-disciplinary: Astronomy, solar and plasma physics, geophysics (Earth magnetic field), biology and meteorology (effects on atmosphere, weather, biosphere), history, languages, cultural impact of astronomical observations on civilizations, etc.
While astronomy so far was the study of everything in the Universe but Earth, Terra-Astronomy also studies Terra (planet Earth) with astrophysical methods: Planet Earth – for us – is an important part of the Universe.