Building the ultimate map of the Milky Way: Here’s what scientists have so far

Building the ultimate map of the Milky Way: Here’s what scientists have so far

Beyond the realm of mind-blowing spaceflights, groundbreaking satellites and jaw-dropping lunar landings, the European Space Agency is focused on a crucial quest. It’s simply “to create the most accurate and comprehensive multi-dimensional map of the Milky Way.”

The ambitious undertaking is called Gaia, and over the past few years ESA has steadily made great strides on the dream. Collaborative scientists have collected tons of spectacular data on more than a billion stars in our galaxy, recording every juicy detail along the way.

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

Luckily for us, he’s also released some standout visuals that encompass the treasure box of cosmic secrets gathered so far. This particular milestone is officially called the Gaia 3 data release – and crucially, it’s the one that the ESA says is “the most detailed survey of the Milky Way to date”.

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

A representation of asteroids in our solar system on June 13, 2022.

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

P. Tanga (Observatory of the Côte d’Azur)

When you look at the statistics from this survey, it’s truly mind-blowing. This new trove of galactic intelligence includes some 6.6 million quasar candidates with estimates of redshifts, i.e. the extremely bright jets that power supermassive black holes, and likely their precise locations. It has 4.8 million candidate galaxies, about 813,000 multistar systems, 2.3 million hot stars, and much more.

“Gaia is a survey mission. This means that by repeatedly surveying the entire sky with billions of stars, Gaia is bound to make discoveries that other, more dedicated missions would miss,” said Timo Prusti, scientist of the Gaia project at ESA. statement.

A map with glowing dots representing galaxies and cosmic clouds.

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

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

Some interstellar surprises

According to the team, among the most startling findings from Gaia Data Release 3 are strange phenomena called “starquakes.”

Starquakes are pretty much exactly what they sound like – tiny movements on a star’s surface that can alter its orblike shape. Some of these earthquakes are compared by the ESA to the vibrations we associate with “large-scale tsunamis” on Earth.

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

Asteroseismology is to the stars what seismology is to the Earth, the study of earthquakes and other wave propagations. A preview of the starquake portion of the new Gaia data can be seen below.

Another startling revelation was that the Gaia telescope duo – which harnesses a massive billion-pixel camera – could detect the chemical makeup of stars being studied. This is a big problem that could revolutionize the field of astronomy.

In short, understanding the exact distribution of chemicals that bind stellar objects together could help us decode when they were born, where they were born, and what trajectory they followed after birth. This could reveal an in-universe timeline.

And with the new data from Gaia, the team discovered that some stars had heavier elements than others. Heavier elements are often metals and are differentiated from lighter elements because they have a different core structure.

A representation of the stars in the Milky Way that are the richest in metals.

This all-sky view shows a sample of the Milky Way stars in version 3 of the Gaia data. The color indicates stellar metallicity. Redder stars are richer in metals.


But the main point here is that the lighter elements, as far as experts know so far, are believed to be the only type present during the Big Bang. In essence, this means that version 3 of the Gaia data offers direct evidence for an extremely diverse combination of stars in our galaxy in terms of time and place of genesis.

“This diversity is extremely important, because it tells us the story of how our galaxy formed,” said Alejandra Recio-Blanco of France’s Côte d’Azur Observatory and member of the Gaia collaboration, in a statement. . “It reveals the processes of migration within our galaxy and of accretion from outer galaxies.”

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

This sky map shows the Milky Way’s velocity field for about 26 million stars. Blue shows parts of the sky where the average motion of the stars is toward us, and red shows 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 of this a step further, seeing Gaia’s efforts somehow reminds us of our place in the universe. Mapping a region much, much larger than the immediate vicinity of the Earth inevitably forces human existence into perspective.

As Recio-Blanco says, “It shows as clearly as our sun, and we, all belong to an ever-changing system, formed through the coming together of stars and gases of different origins.”

Other notable sightings with Gaia include over 800 binary star systems, which refers to two stars orbiting each other, as opposed to the singular sun in our solar system, and a new asteroid study including 156,000 rock bodies.

A multicolored representation of asteroids in the Milky Way.

This image shows the orbits of more than 150,000 asteroids – from inner parts of the solar system to Trojan asteroids at Jupiter’s distance. The yellow circle in the center represents the sun. Blue represents the inner part of the solar system, where there are near-Earth asteroids, Mars cruisers and terrestrial planets. The main belt, between Mars and Jupiter, is green. Jupiter Trojans are red.

P. Tanga (Observatory of the Côte d’Azur)

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

And when it comes to Gaia’s next steps, the team intends to continue working on what will ultimately be the pinnacle of lore from our home galaxy, the Milky Way.

A representation of where we are in the Milky Way galaxy.

This image shows an artistic impression of the Milky Way, plus an overlay showing the location and densities of a sample of young stars from Gaia Data Release 3 (in yellow-green). The sign “you are here” points to the sun.

ESA/Kevin Jardine, Stefan Payne-Wardenaar

Leave a Comment

Your email address will not be published. Required fields are marked *