Building the Ultimate Galaxy Map: Here’s What Scientists Have Done So Far

Beyond the realm of breathtaking spaceflights, groundbreaking satellites and stunning moon landings, the European Space Agency is focused on one crucial quest. It’s just to “create the most accurate and complete multidimensional map of the galaxy”.

The ambitious venture is called Gaia, and in recent years ESA has steadily made great strides with the dream. Scientists from the collaboration have collected tons of spectacular data on the more than 1 billion stars in our galaxy, capturing every juicy detail along the way.

And on Monday, the team reached a huge checkpoint for the project.

Luckily for us, it also released some remarkable images that encompass the treasury of cosmic secrets collected so far. This particular milestone is formally dubbed Gaia Data Release 3 — and more importantly, it’s one that ESA says is the “most detailed galaxy survey to date.”

In this dataset you can not only see thousands of objects in the solar system such as asteroids, moons and other celestial wonders in our galaxy, but you can also view millions of galaxies and phenomena Outside The Milky Way.

An image of asteroids in our solar system on June 13, 2022.

The position of each asteroid has been plotted at 12:00 CEST on June 13, 2022. Blue represents the innermost part of the solar system, where the nearby terrestrial asteroids, Mars cruisers and terrestrial planets are. The main belt, between Mars and Jupiter, is green. The two orange “clouds” correspond to Jupiter’s Trojan asteroids.

P. Tanga (Observatory de la Côte d’Azur)

When you look at the stats on this survey, it’s really overwhelming. This new wealth of galactic intelligence includes some 6.6 million quasar candidates with estimates of redshift, or the extremely bright jets that power supermassive black holes, and likely their precise locations. It has 4.8 million galaxy candidates, about 813,000 multistar systems, 2.3 million hot stars and much more.

“Gaia is a research mission. This means that as Gaia inspects the entire sky multiple times with billions of stars, she will certainly make discoveries that other more dedicated missions would miss,” said Timo Prusti, project scientist for Gaia at ESA, in a statement. .

A map with bright spots of galaxies and cosmic clouds.

The Large and Small Magellanic Clouds appear as bright spots in the lower right corner of the image. The dwarf galaxy Sagittarius is visible as a faint quasi-vertical streak below the galactic center.

ESA/Gaia/DPAC/CU6, D. Katz, N. Leclerc, P. Sartoretti and the CU6 team.

A few interstellar surprises

According to the team, among the most surprising discoveries of Gaia’s data release are 3 strange phenomena called ‘starquakes’.

Starquakes are pretty much exactly what they sound like: tiny movements on a star’s surface that can change its orbital shape. ESA likens some of these tremors to tremors we associate with “large-scale tsunamis” on Earth.

“Starquakes teach us a lot about stars, especially their inner workings. Gaia opens a gold mine for ‘asteroseismology’ of massive stars,” Conny Aerts of KU Leuven in Belgium, and a member of the Gaia collaboration, said in a statement.

Asteroseismology is to stars what seismology is to Earth, the study of earthquakes and other such wave propagation. An overview of the starquake portion of Gaia’s new data can be seen below.

Another notable revelation was that the Gaia telescope duo — which has a camera of a whopping 1 billion pixels — could detect the chemical makeup of the stars under study. This is a major problem that could revolutionize astronomy.

In short, understanding the breakdown of the exact chemicals of stellar objects could help us decipher when they were born, where they were born, and what trajectory they followed after they were born. It could reveal a timeline of the universe.

And with the new Gaia data, the team found that some stars contain heavier elements than others. Heavier elements are often metals and differ from lighter elements in that they have a different core structure.

An image of which stars in the Milky Way are richer in metals.

This view of the entire sky shows an example of the stars of the Milky Way in Gaia’s data release 3. The color indicates the stellar metallicity. Redder stars are richer in metals.


But the main point here is that, as far as experts know so far, lighter elements are considered to be the only species present during the Big Bang. Essentially, this means that Gaia data release 3 provides direct evidence of a super diverse combination of stars in our galaxy, both in terms of time and place of origin.

“This diversity is extremely important because it tells us the story of the formation of our galaxy,” Alejandra Recio-Blanco of the Observatoire de la Côte d’Azur in France, and a member of the Gaia collaboration, said in a statement. . “It reveals the processes of migration within our galaxy and accretion of external galaxies.”

A sky map showing the speed of the stars of the Milky Way.

This sky map shows the Milky Way’s velocity field for about 26 million stars. Blue shows the parts of the sky where the average motion of stars is towards us and red shows the parts of the sky where the average motion is away from us.

ESA/Gaia/DPAC/CU6, O. Snaith, D. Katz, P. Sartoretti, N. Leclerc and the CU6 team.

Taking all this one step further, seeing Gaia’s efforts remind us a bit of our place in the universe. Mapping an area far, far larger than Earth’s immediate vicinity inevitably forces human existence into perspective.

As Recio-Blanco puts it: “It also clearly shows that our sun, and we all belong to an ever-changing system, formed thanks to the assembly of stars and gas of different origin.”

Other notable Gaia observations include more than 800 binary star systems, which refer to two stars orbiting each other, unlike our solar system’s single sun, and a new asteroid survey that includes 156,000 rock bodies.

A multicolored image of asteroids in the Milky Way galaxy.

This image shows the orbits of more than 150,000 asteroids — from the inner solar system to the Trojan asteroids distant from Jupiter. The yellow circle in the center represents the sun. Blue represents the innermost part of the solar system, which is home to near-Earth asteroids, Mars cruisers, and terrestrial planets. The main belt, between Mars and Jupiter, is green. Jupiter Trojans are red.

P. Tanga (Observatory de la Côte d’Azur)

“We can’t wait for the astronomy community to dive into our new data to learn even more about our galaxy and its environment than we could have imagined,” said Prusti.

And regarding Gaia’s own next steps, the team plans to continue toiling on what will eventually be the pinnacle of knowledge for our own galaxy, the Milky Way.

An image of where we are in the Milky Way.

This image shows an artist’s impression of the Milky Way, overlaid with the location and densities of a young star sample from Gaia’s data release 3 (in yellow-green). The sign “you are here” points to the sun.

ESA/Kevin Jardine, Stefan Payne-Wardenaar

Leave a Comment