Generic diagram of the equinox
The spring equinox in the year 2025
The spring equinox in the year 2025 will occur on March 20 at 11:01:30.18 AM, Romanian Legal Time.
The Earth follows an orbit in space, which can be approximated as a great circle. The plane in which Earth's orbit lies is called the ecliptic plane. From Earth's perspective, it is equivalent to consider that the Sun follows the same orbit around a fixed Earth.
On the other hand, the Earth is tilted in space, so its rotational axis is not perpendicular to the plane of its orbit, meaning it is not perpendicular to the ecliptic plane. However, by definition, its rotational axis is perpendicular to the plane defined by the equator. This plane is called the celestial equatorial plane. The two planes—the ecliptic plane and the celestial equatorial plane—are therefore inclined relative to each other.
Thus, by definition, the moment of the equinox is the instant when the Sun is located at the specific point determined by the intersection of these two fundamental planes. In other words, during the equinoxes, the Sun is in the plane of the celestial equator. Since there is only one celestial equator (which divides the Earth in two and is perpendicular to its axis of rotation) and only one Sun, the moments of the equinoxes are unique, regardless of our location on Earth.
We define the dates of the equinoxes and solstices, which mark the beginning of the astronomical seasons, as the moments when the apparent planetocentric longitude of the Sun (including the effects of aberration and pole motion) is an exact multiple of 90°.
In the year 2025, the spring equinox will occur on March 20 at 9:01:30.18 AM Coordinated Universal Time (UTC). For Romania, this moment corresponds to March 20, 2025, at 11:01:30.18 AM Romanian Legal Time. The spring equinox for countries in the Northern Hemisphere corresponds to the autumn equinox in the Southern Hemisphere.
AIRA's educational team engages visitors in discussions about Earth's place in the Cosmos, exploring its relationship with meteors, asteroids, comets, and other celestial bodies.
Astronomical Institute showcases the mysteries of space sciences at the French Cultural Center
On Tuesday, February 11, 2025, the Astronomical Institute of the Romanian Academy (AIRA) participated in the "In the Heart of Sciences" event at the French Institute in Romania, marking the International Day of Women and Girls in Science. The event gathered students from various high schools, offering them the opportunity to explore the world of scientific research.
AIRA’s stand was an immersive experience, featuring roll-up displays that introduced attendees to the history of astronomical research in Romania and to some of its past technological assets. The discussion on small celestial bodies in the Solar System began with an hands-on moment: students were invited to examine a real meteorite fragment discovered in Africa, billions of years old, through the microscope. This tangible piece of space set the stage for a deeper exploration of asteroids, comets and dwarf planets through a series of detailed 3D-printed models.
A special instrument of the AIRA's exhibition was the historic 1893 Bardou refracting telescope, used for solar observations. This French-made telescope offered visitors a glimpse into Romania’s long-standing contributions to astronomy.
Astronomical Institute educational team also emphasized Romania’s active role in space surveillance. The discussion expanded to our nation’s capabilities in tracking celestial objects through the MOROI (Meteorites Orbits Reconstruction by Optical Imaging) network. This system enhances the monitoring of meteors and fireballs, utilizing advanced machine learning techniques to filter and analyze celestial events.
Through this engaging presentation, AIRA inspired young minds to look beyond Earth and consider careers in science and technology. The institute remains dedicated to fostering public interest in science and astronomy and ensuring that the next generation continues to explore the vast mysteries of the Universe.
Scientific progress in astronomy and multidisciplinary dynamic assimilation in Romania
On November 13, 2024, the Cluj-Napoca Branch of the Romanian Academy hosted a roundtable discussion dedicated to multidisciplinary dynamics linked to advancements in the field of astronomy. The event provided an opportunity to reflect on contemporary developments in this domain, comparable to the great geographical discoveries of the 15th and 16th centuries.
During the meeting, discussions focused on integrating new scientific discoveries into the Romanian education system, developing Romania's research infrastructure, and enhancing specialized human resources in the field of astronomy. The debates revolved around key questions concerning the ability of Romanian research and educational institutions to adapt to this immense flow of information and the changes it entails. Among the questions addressed were the following:
- How are Romanian research and educational institutions coping with this massive flow of information and the paradigm shifts it will bring?
- What is the capacity to incorporate new discoveries into educational programs?
- How capable is Romania’s research infrastructure of aligning with global standards?
- How far are we from achieving a critical mass of researchers in astronomy to meet the challenges of our time?
The event brought together astronomers from the Astronomical Observatory in Cluj-Napoca and the Astronomical Observatory in Bucharest, both part of the Astronomical Institute of the Romanian Academy, alongside experts from related fields such as mathematics, physics, philosophy, computer science, and other cultural areas.
The official poster of the event
Distribution of the taxonomic classes obtained for all objects of the NEOROCKS survey color data.
Neorocks final results - Romanian astronomers get involved
NEOROCKS stands for Near Earth Objects, Rapid Observations, Characterization and Key Responses.
NEOROCKS has connected expertise in performing small body astronomical observations and the related modelling needed to derive their dynamical and physical properties, to the pragmatic planetary defense approach, which aims to provide operational loops and information systems to protect citizens and ground infrastructures from potential threats. For more than three years the European consortium collected astronomical observations, modelled dynamically and physically surfaces and internal properties of Near Earth Objects (NEOs).
One of the objectives of NEOROCKS is to characterize as many Potential Hazardous Asteroids (PHAs) as possible in terms of their colors. NEOs have small diameters and can be observed from ground-based telescopes during close encounters with Earth. Their favorable geometries, sometimes for a time period of hours and days, need to be used to perform as many observations as possible in order to have access to several parameters that will ultimately aid in constraining their mass, shape, surface composition, surface rugosity, and internal structure.
The final results of the NEOROCKS color database are composed of 170 objects that were observed for more than 63 nights between 2020 and 2023. Most of these observations were carried out at the Observatoire de Haute Provence in France. A few observations were performed at the Pic du Midi Observatory (also in France). The survey was done in four broadband filters, namely B, V, R, and I. The sample also contains values of colors for asteroid (99942) Apophis, which will graze the Earth on April 13, 2029.
The statistics of the taxonomical types clearly indicate a large percentage of rocky silicate-rich asteroids (S-complex taxon). For objects with diameters smaller than 500 m, approximately 59% of them are S-type objects. This large percentage is mainly due to a bias induced by the surface reflectivity of objects (S-type asteroids are more reflective than C-type objects).
The chaos for the objects of the NEOROCKS color database was determined using the Lyapunov time of each object. The statistics show that the average Lyapunov time does not go beyond 100 years.
Several objects of the NEOROCKS color database have orbits similar to those of meteoroids associated with meteor showers. Among them, the asteroid 2011 OL51 was validated by two metrics used for this investigation, and it may be one of the parent bodies of the OCC meteor shower.
For more information on the subject follow the link here enclosed.
Birlan M., Barucci, M.A.,…, Sonka A.,…, Nedelcu A., …, Anghel S., et al - NEOROCKS color survey: Final results, Astronomy & Astrophysics, Volume 689, id.A334, 2024, https://www.aanda.org/articles/aa/pdf/2024/09/aa50495-24.pdf