Glossaries | UNIVERSEH

Tuesday, 8 September 2026, 12:05 PM

Site: UNIVERSEH: The European Space University

Course: UNIVERSEH: The European Space University (UNIVERSEH)

Glossary: Dictionary of Space Concepts

Gamma ray

(Last edited: Saturday, 30 September 2023, 8:30 PM)

Illustration of an emission of a gamma ray ( γ ) from an atomic nucleus Source: https://en.wikipedia.org/wiki/Gamma_ray#/media/File:Gamma_Decay.svg

Short Definition:

Gamma rays are very high frequency electromagnetic radiation emitted as an outcome of radioactivity. Due to high frequency, gamma rays have very high energy. Natural sources of gamma emission originating on Earth are mainly an effect of radioactive decay and secondary radiation from atmospheric interactions among cosmic ray particles.

Detailed Definition:

A gamma ray, also known as gamma radiation, is a penetrating form of electromagnetic radiation originating from the radioactive decay of atomic nuclei. Gamma rays from radioactive decay are within the energy range starting at few kiloelectronvolts (keV) to roughly 8 megaelectronvolts (MeV), matching to the usual energy levels in nuclei among reasonably long lifetimes. The energy spectrum of gamma emission can be utilized to recognize the decaying radionuclides with a technique called gamma spectroscopy. Very-high-energy gamma rays in the 100–1000 teraelectronvolt (TeV) range have been observed from sources such as the Cygnus X-3 microquasar.

Etymology:

gamma - The third letter of the Greek alphabet (Γ, γ),
radiation - From the past participle stem of Latin radiare (“to gleam, shine, beam”).

Sample Sentence(s):

"Solar flares emit across the entire electromagnetic spectrum, including gamma rays."
"Gamma rays originating from far-distant quasars are used to estimate the extragalactic background light in the universe."

Translations:

French:

Rayon gamma

German:

Gammastrahlung

Polish:

Promieniowanie gamma, promienie gamma

Swedish:

Gammastrålning

Links to Videos/Articles:

Geosynchronous orbit

(Last edited: Thursday, 31 August 2023, 5:13 PM)

Projection of the path traced by geosynchronous satellites of different inclinations. Source: Wikipedia

Short Definition:
Geosynchronous orbit is an orbit with orbital period matching Earth's full rotation time.

Detailed Definition:
Objects in geosynchronous orbit appear to trace out a path on the sky, typically a figure-8 shape every day. The exact path depends on orbit's eccentricity and inclination, but the object can be observed in the same place on the sky, same time every day. This type of orbit is useful for example for Earth observing satellites.

Etymology:
From ancient greek geo (Earth) + synchronous

Sample Sentence(s):
A satellite is placed in geosynchronous orbit above Europe.

Translations:

French:
orbite géosynchrone

German:
geosynchrone Umlaufbahn

Polish:
Orbita geosynchroniczna

Swedish:
geosynkron bana

Links to Videos/Articles:
https://www.space.com/29222-geosynchronous-orbit.html
https://gisgeography.com/geosynchronous-geostationary-orbits/

Gravity

(Last edited: Friday, 26 May 2023, 5:25 PM)

Image/Video/Audio:

Image/Video/Audio Source:

Short Definition:

Gravity is one of the fundamentals of the universe and the force of attraction between every single existing body. It keeps the universe and our solar system, together.

Detailed Definition:

One of the first theories about the existence of gravity was made by Aristotle, a Greek philosopher. He believed that objects tend toward their inner heaviness. Many researches and scientists later, this theory became more developed and finally, in XVII century Isaac Newton (after being hit by the famous apple) described gravity as a force that keeps the planets in their place. This definition evolved into a law and formula (F=G*(M*m)/r^2) which we use today.

Every object has its gravitational field. The heavier the object, the greater is its force of attraction in this field. An apple has its gravitational field too, however it weighs thousands of times less than a planet. That is why we don't see it every day. The gravitational force of a planet is so big that we need a great speed and precise calculations to be able to fly away from it and not be brought back. It is measured by the acceleration it gives to the falling object. For example, at Earth's surface it is equal to 9,81 m/s and at the Moon's only 1,6 m/s.

Etymology:

from Old French, or from Latin gravitas ‘weight, seriousness’

Sample Sentence(s):

Every object with mass has gravity. Gravity creates stars and planets by pulling together the material from which they are made.

Translations of Terms/Concepts into Partner Languages [Multiple fields for entering the translation of the term in each partner language, additional languages can potentially be added, e.g. Russian, Chinese, Portuguese]

French:

la gravité

German:

die Schwere

Polish:

grawitacja

Swedish:

allvar

Links to Videos/Articles:

https://en.wikipedia.org/wiki/History_of_gravitational_theory

https://spaceplace.nasa.gov/what-is-gravity/en/

https://www.britannica.com/science/gravity-physics

Gravity Assist

(Last edited: Monday, 13 March 2023, 3:55 PM)

Source: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=2143, https://commons.wikimedia.org/w/index.php?curid=18049439

Short Definition:

Gravity assistance describes the intentional use of the gravitational attraction of a celestial body, in order to modify the trajectory of a space vehicle. This maneuver allows the spacecraft to save rocket fuel.

Detailed Definition:

Etymology:

1. Gravity (Noun.), originating from the Latin word gravitatem, with the meaning of “weight, heaviness, pressure”

2. Assist (Verb.), originating from Latin word assistere, which means “standing by, help”

Sample Sentence(s):

“The global minimum velocity increments of direct transfer trajectory and gravity-assist trajectories are obtained for each candidate target.”

Translations:

French: Assistance gravitationnelle
German: Schwerkraftumlenkung
Polish: Asysta grawitacyjna
Swedish: Gravitationsslunga

Links to Videos/Articles:

"Section 1: Environment, Chapter 4: Trajectories". Basics of Space Flight. NASA.
"Gravity assist". The Planetary Society.

Great Red Spot

(Last edited: Thursday, 31 August 2023, 5:14 PM)

Sources: Stewart, P. (2018, June 8). Jupiter. flickr. https://www.flickr.com/photos/106648653@N05/42658035711

Definition:

A persistent large anticyclonic storm in the atmosphere of Jupiter, 22° south from its equator, which has been continuously observed since the 19^th century.

As of 2021, the Great Red Spot is reported to be about 10,000 miles across and 300 miles deep into the atmosphere of Jupiter. However, according to NASA observations, it is shrinking and becoming taller, and it is not yet clear whether the Great Red Spot will stabilize or disappear completely.

Translation:

French: la Grande Tache rouge
German: der Große Rote Fleck
Polish: Wielka Czerwona Plama
Russian: Большое Красное Пятно
Swedish: Stora röda fläcken

Links to Videos/Articles:

https://www.youtube.com/watch?v=JDi4IdtvDVE

Heavy Element

(Last edited: Thursday, 31 August 2023, 5:16 PM)

Image/Video/Audio: Image: Periodical Table Image/Video/Audio Source: https://commons.wikimedia.org/wiki/File:Ionization_energy_periodic_table.svg

Short Definition:

Heavy elements are the general name for elements containing atomic numbers greater than 92. Above these, elements with atomic numbers 112 and above are called superheavy elements. The state that creates the atomic number is the number of protons in the nucleus of the element.

Detailed Definition:

Heavy elements, which are determined by the number of protons in the nucleus of the element (this called atomic number) are elements with atomic number greater than 92. One row above them there is superheavy elements with atomic numbers greater than 112. The first artificially produced heavy and superheavy elements were first produced during the Cyclotron experiments.

One of the most important issues about heavy elements is the concept of 'island of stability'. This concept refers to the region in the table of nucleides where elements with half-lives longer than some other super heavy elements are found. However, it should be noted that we are ona narrow time scale, from minutes to micro/nano seconds at most. The term was first coined in 1998 with the discovery of the super heavy element 114 (Flerovium).

Etymology:

Heavy – From Proto Germanic (hafiga)

Element – From Latin (elementum)

(origin and meaning of heavy. (n.d.). Etymonline. https://www.etymonline.com/word/heavy)

(element - Wiktionary. (n.d.). https://en.wiktionary.org/wiki/element)

Sample Sentence(s):

‘’The heaviest element known at the end of the 19th century was uranium, with an atomic mass of approximately 240 (now known to be 238) amu.’’

(Wikipedia contributors. (2022, December 31). Superheavy element. Wikipedia. https://en.wikipedia.org/wiki/Superheavy_element)

‘’Although the scientific community has assigned these heaviest elements to their own spots on the periodic table, there is still a lot we don’t know about them.’’

(Exploring the superheavy elements at the end of the periodic table. (n.d.). cen.acs.org.)

Translations of Terms/Concepts into Partner Languages:

French:

Élément lourd

German:

Schweres element

Polish:

Ciężki pierwiastek

Swedish:

Tungt element

Turkish:

Ağır Element

Links to Videos/Articles:

Cookie Absent. (n.d.). https://physicstoday.scitation.org/action/cookieAbsent

Discovery of Elements 113 and 115. (n.d.). https://pls.llnl.gov/research-and-development/nuclear-science/project-highlights/livermorium/elements-113-and-115

Seeker. (2019, November 10). This Superheavy Atom Factory Is Pushing the Limits of the Periodic Table [Video]. YouTube. https://www.youtube.com/watch?v=kg0AN8bZ4us

Wikipedia contributors. (2022, December 31). Superheavy element. Wikipedia. https://en.wikipedia.org/wiki/Superheavy_element

Periodical Table.png

Heliosphere

(Last edited: Friday, 26 May 2023, 5:25 PM)

Term/Concept:

Heliosphere

Image/Video/Audio:

Image/Video/Audio Source:

Short Definition:

The Heliosphere is the extended layer of the Sun consisting of its magnetosphere, astrosphere and atmosphere. It has a bubble-like shape, covering the entire Solar System.

Detailed Definition:

The Heliosphere in physics terms is a cavity that is formed by the Sun in its neighbourhood. It binds our solar system together, like an atmosphere on Earth binds life on the surface. It also produces weather conditions like the ones on Earth, but the weather happens on a larger, solar system scale.

The Heliosphere consists of plasma, particles and magnetic fields that interact with the space environment, producing what we call space weather. It is also a shield, without which we probably would not exist, as it protects our planet from cosmic rays, particles created far away in space. Without the existence of a heliosphere, our living cells would be continuously bombarded, causing damage.

As this wave of solar wind wanders away from the Sun, at some point it reaches termination shock, where its speed suddenly drops from even 700 km/s. Beyond the termination shock lies the heliosheath, the outer region of the heliosphere, where solar wind becomes denser and hotter as it presses towards wind in interstellar space. The boundary between it and the interstellar wind is called heliopause, the pressure of both of the winds stays in balance there.

Etymology:

helio- +‎ -sphere

helio - from Ancient Greek ἥλιος (hḗlios).

sphere - from Ancient Greek σφαῖρα (sphaîra, “ball, globe”)

Sample Sentence(s):

Voyager 1 travelled through the heliosphere and encountered heliopause in 2015.

As the heliopause marks the boundary between the matter originating from the Sun and matter originating from the rest of the galaxy, the spacecrafts that left the heliosphere are travelling through interstellar space.

French:

Héliosphère

German:

Die Heliosphäre

Polish:

Heliosfera

Swedish:

Heliosfären

Links to Videos/Articles:

https://www.nasa.gov/mission_pages/sunearth/science/Heliosphere.html

https://sci.esa.int/web/ulysses/-/2576-the-heliosphere

https://www.thesuntoday.org/heliosphere/

Hubble Space Telescope

(Last edited: Thursday, 31 August 2023, 5:17 PM)

Short Definition
Hubble Space Telescope is a large telescope used to observe distant space objects. Hubble can observe almost complete light spectrum from the ultraviolet to near infrared light allowing extensive research of space. Its research includes but is not limited to beginning of the Universe, black holes, exoplanets and nebulas.

Detailed Definition
Hubble is a Cassegrain mirror telescope. It is built with two hyperbolically curved mirrors that are positioned facing each other. The main mirror that accumulates the light from celestial bodies is curved inwardly and leads light to the secondary smaller mirror. Second mirror is curved outwardly and diffuses the light bouncing it back to the first mirror. At the main mirror the light is finally collected together and lead to the focal point where optical instruments can gather the data.

Hubble was launched in 1990 and has been visited multiple times between 1993 and 2009 by astronauts. Those missions included various repairs like correcting mistakes that were noticed first after we started collecting the data and adding new science instruments to make information analysis easier.

Hubble studies helped us understand our Universe better being the first telescope located outside of Earth's atmosphere that prevented us from research of ultraviolet light that is only visible in space. One of the most important discoveries that Hubble made include:
-More accurate estimate on age of the Universe,
-Determining the rate with which the Universe is expanding,
-Discovering that almost every big Galaxy has a black hole at its center.

Etymology
Hubble Space Telescope is named after Edwin Powell Hubble, who made one of the most important discoveries in the field of astronomy in the 20th century.

Sample Sentence(s):

Hubble Space Telescope helped researchers make new discoveries.

Astronomers around the world use Hubble Space Telescope to research new exoplanets.

Translations of Terms/Concepts into Partner Languages:

French: Hubble

German: Hubble-Weltraumteleskop

Italian: telescopio spaziale Hubble

Polish: Kosmiczny Teleskop Hubble’a

Swedish: Hubbleteleskopet

Links to Videos/Articles:

Space Telescope Science Institute (n.d.), Hubblesite, Retrieved from Website hubblesite.org
Garner, R. (2017, December), Observatory – Optics, Retrieved from https://www.nasa.gov/content/goddard/hubble-space-telescope-optics-system
Royal Museum Greenwich (n.d.), What has the Hubble Space Telescope Discovered?, Retrieved from https://www.rmg.co.uk/stories/topics/what-has-hubble-space-telescope-discovered
NASA, ESA (2000, January), Hubble Space Telescope, SM3A, Retrieved from https://esahubble.org/images/sts103_713_048/

Hubble's Law

(Last edited: Saturday, 30 September 2023, 8:40 PM)

Wikipedia contributors. (n.d.). File:Hubble constant.JPG - Wikipedia. https://upload.wikimedia.org/wikipedia/commons/2/2c/Hubble_constant.JPG

Short Definition:

Hubble's Law is a concept formed by Edwin Hubble, defining a positive relation between the distance and the speed of galaxies moving away from earth. The further they are, the faster they move away. This theory was a base to observe the expansion of universe.

Detailed Definition:

Hubble's law defines a relation between distance of galaxies and their speed of moving away from each other. The concept was observed through detection of redshift emitted by these galaxies, visible from earth. In simpler terms, the galaxies emit light on a spectrum further towards the red extreme, which can be observed by comparing measurements from different times, to calculate that the light has changed its wavelength and frequency, thus shifting on the visible light spectrum. The theory proves that the universe is constantly expanding, and thus it contributes to the Big Bang Theory. The constant movement of galaxies away from earth and each other, points to the increase of space in the universe. The theory also derives a so called, Hubble's constant which is a measure of how fast a given galaxy moves away at a given distance, and it comes out to around 70 (km/s)/Mpc which translates to expansion of 70 kilometres per second for every megaParsec of distance from the galaxy. Thus, for a galaxy 1 megaParsec away from earth, the structure moves away at a speed of 70 km/s.

Etymology:

Hubble's Law comes from the last name of the physicist Edwin Hubble.

Sample Sentence(s):

1. Hubble's Law contributed largely to the theory of relativity.
2. Hubble's Law proves that the universe is constantly expanding.

Translations:

French - Loi de Hubble

German - Hubbles Gesetz

Italian - Legge di Hubble

Polish - Prawo Hubble'a

Swedish - Hubbles lag

Ilmenite

(Last edited: Wednesday, 16 August 2023, 12:42 PM)

Short Definition:

A usually massive iron-black mineral that consists of an oxide of iron and titanium and that is a major titanium ore.

Detailed Definition:

Ilmenite is named after the Ilmenski mountains in Russia, where the mineral was first discovered. It is slightly magnetic, which means that magnets can be used to separate it from other minerals in sand deposits. Ilmenite is also a common accessory mineral in igneous rocks, sediments, and sedimentary rocks in many parts of the world. Also, it is a black iron-titanium oxide with a chemical composition of FeTiO3.

Etymology:

Named after Ilmen Mountains in Russia +‎ -ite in 1827.

The suffix –ite is used to form nouns denoting rocks or minerals, from Latin -ītēs, and from Ancient Greek -ῑ́της.

Sample Sentences:

"Ilmenite is an economically important and interesting mineral."

"Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics."

Translations:

French: Illménite
German: Ilmenit
Polish: Ilmenit
Swedish: Ilmenit