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[SITUATION] · [ACTIVE]

3 clusters · 14 sources · 5 days · First seen 9 days ago · Last updated 4 days ago

Categories: TECHNOLOGY · INTERNATIONAL

Milky Way disk flip from Gaia‑Sausage collision

Entities: Durham University · Milky Way Galaxy · Auriga simulation suite · Gaia‑Sausage‑Enceladus · Gaia‑Enceladus

Overview

Astronomers have built a growing case that a head‑on merger with the ancient dwarf galaxy Gaia‑Sausage‑Enceladus reoriented the Milky Way’s stellar disc by roughly 90 degrees. Early Durham University simulations showed the impact shredded the dwarf, deposited its stars in the halo and caused a gradual disc flip over several hundred million years. A suite of 25 Milky Way‑like simulated galaxies later linked such frontal mergers to the Galaxy’s unusually slow‑rotating halo and to the elongated “Sausage” component.

British researchers, using the Auriga cosmological simulations of the same analogues, argued that a collision more than 10 billion years ago likely altered the Galaxy’s orientation, tying halo rotation to the surrounding dark‑matter halo. Recent work presented at the 2026 National Astronomy Meeting in Birmingham, led by Kirill Batrakov and collaborators, reinforced these findings. Their analysis of the 25‑galaxy sample confirmed that the slow halo rotation is a hallmark of strong frontal impacts and suggested the disc could have reversed its tilt by up to 90 degrees, reshaping the Sun’s past trajectory and the coupled evolution of the stellar and dark‑matter halos.

Claims

What the coverage asserts, and how well corroborated each claim is across sources.

[● 8 SOURCES] The Milky Way collided frontally with the dwarf galaxy Gaia‑Sausage‑Enceladus about 10‑11 billion years ago. (Astronomers)
[● 4 SOURCES] The collision may have caused the Milky Way’s disc to rotate up to 90 degrees, effectively reversing its orientation. (Study authors)
[● 2 SOURCES] Simulations of 25 Milky Way‑like galaxies show that a slowly rotating stellar halo correlates with a past major merger. (Simulation team)
[● 2 SOURCES] The research was presented at the National Astronomy Meeting 2026 in Birmingham, organised by the Royal Astronomical Society. (Conference program)
[● 2 SOURCES] The collision likely altered the Sun’s past orbital trajectory within the galaxy. (Study authors)
[● 2 SOURCES] The evolution of the stellar halo appears linked to the evolution of the Milky Way’s dark‑matter halo. (Authors)

Timeline

4 days ago

[TECHNOLOGY] 2 sources
Milky Way found larger than thought and may have flipped orientation after ancient collision
Studies reveal the Milky Way is larger than believed and may have flipped orientation after an ancient merger with Gaia‑Enceladus.
6 days ago

[TECHNOLOGY] 8 sources
Milky Way flipped after ancient galactic collision, study finds
Simulations and halo data suggest a 10‑11 billion‑year collision with Gaia‑Sausage‑Enceladus turned the Milky Way’s disk around 90°, reshaping its structure and the Sun’s orbit.
9 days ago

[INTERNATIONAL] 4 sources
Milky Way’s Disc Flipped by Ancient Gaia Sausage Collision
A head‑on collision with the dwarf galaxy Gaia Sausage 10 billion years ago likely flipped the Milky Way’s disc over 90°, explaining the slow‑moving halo stars and reshaping the galaxy.

Sources

6yka.com · aeiou.pt · blitzquotidiano.it · chosic.com · english.madhyamam.com · geo.fr · ilmeteo.net · naukawpolsce.pap.pl · newsbeast.gr · olhardigital.com.br · primeirojornal.com.br · spidersweb.pl · techno-science.net · ygeia.tanea.gr

This summary has been updated 3 times: see revision history