Explained | What is the Gaia space mission and what has it revealed about the Milky Way?

Explained | What is the Gaia space mission and what has it revealed about the Milky Way?

The story so far: A third data set released by the European Space Agency’s Gaia Astronomical Survey, which includes approximately 1.8 billion stars in the Milky Way galaxy, has revealed an unexpected event called ‘starquakes’, similar to earthquake-like movements but on the faces of the stars.

The information has also revealed the largest chemical map of the entire Milky Way, showing the DNA of millions of stars, including their age, size, chemical composition, color, temperature, and metal. In addition, new data also makes discoveries about two-star systems, quasars, asteroids, and exoplanets.

Scientists, in the years to come, will translate a few terabytes of data to discover what is available about astronomical conditions. The second data collection in 2018 allowed astronomers to predict that the Milky Way collided with another galaxy during a powerful collision 10 billion years ago.

Anatomy of the Milky Way

Milky Way Building. Photo: European Space Agency

The Milky Way galaxy, which is our home galaxy, is just one of nearly 200 billion galaxies of various shapes and sizes in the universe. Nearly 13 billion years old, the Milky Way is a blocked galaxy containing 100 to 200 billion stars, with the sun as the star of the universe.

The galaxy has a flat disk that spreads over 100,000 light-years across. Most of the stars are found in disks, dispersed by a mixture of gases and cosmic dust. The Milky Way galaxy has a central nucleus that focuses on its nearly 10 billion stars. The sun is located between the navel and the surrounding galaxy.

Besides the bump and the disc there is a halo of isolated stars and ancient constellations, and on top of that there is an even greater halo of invisible black objects.

The Milky Way is part of a group of local galaxies, including Andromeda — its closest galaxy, with about 60 smaller galaxies.

What is the function of Gaia?

Gaia mission specifics. Photo: European Space Agency Details of the Gaia mission. Photo: European Space Agency

Gaia is an ongoing astronomical campaign launched in December 2013 by the European Space Agency (ESA) with the aim of creating a more accurate and complete 3D map of the Milky Way by examining 1% or one billion of the 100 billion galaxies in the galaxy. According to the ESA, “this information allows astronomers to reconstruct galaxies in the past and in the future over billions of years.”

The Gaia spacecraft was launched in Kourou, French Guiana in 2013 with the Soyuz rocket and began scientific experiments in 2014. The space shuttle is equipped with two optical telescopes and the largest digital camera in space or a billion-pixel camera, with over 100 electronic detectors. This camera is accurate enough to capture a distance of human hair from a distance of 1,000 miles.

The spacecraft is strategically located 1.5 million km from Earth, on the other side of the sun, in the orbit of the space station called Lagrange 2 or L2.

From here Gaia charted precisely the position, movement, speed, brightness, temperature, and star formation in the galaxy and other celestial objects beyond it.

Gaia’s three screening techniques. Photo: European Space Agency Three Gaia test methods. Photo: European Space Agency

To study the stars and objects, Gaia also has three-dimensional exploration and photographic systems — astronomy, photometry, and spectroscopy. Astrometry is the science of measuring the movement and position of stars in an airplane, photometry examines the color, brightness and other features of the available stars, and spectroscopy measures the speed of light or the movement of stars toward or away from us by reading. stellar spectra or star fingerprints. Spectra is obtained by transmitting light from a star by prism which divides it into colors.

Gaia’s predecessor, ESA’s Hipparcos campaign, made a map of the precise locations of 100,000 stars and was able to view 1,600 light years. Gaia, on the other hand, does not match the start with up to 30,000 lightyears.

Gaia examines millions in a single day and the raw data observed by the spacecraft is processed into sound scientific information by the Gaia Data Processing and Analysis Consortium (DPAC), a team of 400 scientists.

The Gaia data release was organized into four phases – the first two databases were released in 2016 and 2018 respectively, the third set is current, and the final data will be released in 2030 after Gaia has completed the 2025 sky mapping.

What did the new data reveal?

Specifics of the new data collected by Gaia. Photo: European Space Agency Specification of new data collected by Gaia. Photo: European Space Agency

A new set of released data was collected from the Gaia study between 2014 and 2017 and contains advanced information about nearly two billion celestial bodies – including stars in the Milky Way, extraterrestrial objects and those inside our solar system. Contains the largest three-dimensional map of the stars in the Milky Way. The map shows the chemical composition and past and future star movements.

Astrology: One of the most surprising findings, ESA said, was not designed to see, Gaia, more than 100,000 ‘stars’ – which could be compared to tsunamis or massive earthquakes that could change their shape. Such tremors were also found on the surface of stars, which were not supposed to be as vibrant as the astronomical observations existing.

“Starquakes teach us a lot about stars, especially their inner workings. Gaia opens a gold mine of ‘astroseismology’ for big stars, ”said Belgian-based scientist Conny Aerts, who is part of the Gaia partnership.

Quasars: Quasars work wonders and the bright cores of galaxies are powered by huge black holes. These are the brightest objects in the universe and can be seen from afar. Gaia’s new data revealed estimates of more than a million certified quasars and related data for 6.6 million people selected. This is an increase from the previous database that provided positions for half a million certified quasars. The discovery of new quasars is important as it helps to measure the remotest parts of our universe.

Stellar DNA: Data shows the chemical components, colors, brightness, speed, temperature, and position of millions of stars. The chemical composition of the stars also reveals what elements they contain. Only light elements (hydrogen and helium) were formed during the Big Bang. Heavy elements, which scientists call metal, are built into the stars, and when they die, new stars are formed by breakers of dead stars. So the chemical composition can be used to determine which stars were born in another galaxy and then moved to the Milky Way. According to the ESA, astronomers hope to use the information to better understand how stars are born and died, and how the Milky Way emerged over billions of years.

Previous Gaia data revealed precise locations or 2D star movements (the orbital motion), but the new set shows the radial velocity of 33 million stars, that is, the speed of these stars in each direction, or farther away. . from us. . This could not only help scientists find the path of the stars, but also where they came from.

Dual Star: Binary star systems are two stars orbiting in a shared center. New data has revealed the location, distance, orbits, and quantity of more than 8,00,000 binary star systems. Scientists can extract from this data the vast number of individual stars of the binary system, the function of the stars, and the discovery of one of the two stars as the exoplanet — a planet that exists outside of our solar system and often orbits a star.

Asteroids and galaxies: Data has provided a catalog of more than 156,000 asteroids in our Solar System, including their size, shape, color, and brightness (from which details of their position and orbit) can be obtained). In addition to mapping the Milky Way, information has gleaned 2.9 million other galaxies, including the position of the stars, the distance, and the time of their appearance.


I am Sanjit Gupta. I have completed my BMS then MMS both in marketing. I even did a diploma in computer software and Digital Marketing.

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