Andromeda–Milky Way collision
The Andromeda–Milky Way collision is a
Certainty
The Andromeda Galaxy is approaching the Milky Way at about 300 km/s (200 miles per second)
Such collisions are relatively common, considering galaxies' long lifespans. Andromeda, for example, is believed to have collided with at least one other galaxy in the past,
The studies also suggest that M33, the Triangulum Galaxy—the third-largest and third-brightest galaxy of the Local Group—will participate in the collision event, too. Its most likely fate is to end up orbiting the merger remnant of the Milky Way and Andromeda galaxies and finally to merge with it in an even more distant future. However, a collision with the Milky Way, before it collides with the Andromeda Galaxy, or an ejection from the Local Group cannot be ruled out.[9]
Stellar collisions
While the Andromeda Galaxy contains about 1 trillion (1012) stars and the Milky Way contains about 300 billion (3×1011), the chance of even two stars colliding is negligible because of the huge distances between the stars. For example, the nearest star to the Earth after the Sun is Proxima Centauri, about 4.2 light-years (4.0×1013 km; 2.5×1013 mi) or 30 million (3×107) solar diameters away.
To visualize that scale, if the Sun were a
Black hole collisions
The Milky Way and Andromeda galaxies each contain a central
Fate of the Solar System
Two scientists with the Harvard–Smithsonian Center for Astrophysics stated that when, and even whether, the two galaxies collide will depend on Andromeda's transverse velocity.[3] Based on current calculations they predict a 50% chance that in a merged galaxy, the Solar System will be swept out three times farther from the galactic core than its current distance.[3] They also predict a 12% chance that the Solar System will be ejected from the new galaxy sometime during the collision.[16][17] Such an event would have no adverse effect on the system and the chances of any sort of disturbance to the Sun or planets themselves may be remote.[16][17]
Excluding
Possible triggered stellar events
When two spiral galaxies collide, the hydrogen present on their disks is compressed, producing strong star formation as can be seen on interacting systems like the Antennae Galaxies. In the case of the Andromeda–Milky Way collision, it is believed that there will be little gas remaining in the disks of both galaxies, so the mentioned starburst will be relatively weak, though it still may be enough to form a quasar.[17]
Merger remnant
The galaxy product of the collision has been named Milkomeda or Milkdromeda.[20] According to simulations, this object is likely to be a giant elliptical galaxy, but with a centre showing less stellar density than current elliptical galaxies.[17] It is, however, possible the resulting object will be a large lenticular or super spiral galaxy, depending on the amount of remaining gas in the Milky Way and Andromeda.[21]
Over the course of the next 150 billion years, the remaining galaxies of the Local Group will coalesce into this object, effectively completing its evolution.[22]
See also
References
- ^ S2CID 53071357.
- ^ S2CID 124815138.
- ^ a b c Muir, Hazel (2007-05-14). "Galactic merger to 'evict' Sun and Earth". New Scientist. Archived from the original on 20 April 2014. Retrieved 2014-10-07.
- ISSN 0091-6358.
- ^ Gough, Evan (12 February 2019). "Universe Today". The Astrophysical Journal. Retrieved 12 February 2019.
- ^ a b NASA (2012-05-31). "NASA's Hubble Shows Milky Way is Destined for Head-On Collision". NASA. Archived from the original on 1 July 2014. Retrieved 2012-10-13.
- ^ Jason Kottke. "Behold Our Dazzling Night Sky When the Milky Way Collides with Andromeda in 4 Billion Years".
- ^ "Astronomers Predict Titanic Collision: Milky Way vs. Andromeda | Science Mission Directorate". science.nasa.gov. Archived from the original on 2022-10-01. Retrieved 2018-10-13.
- ^ S2CID 53071454.
- S2CID 26797522.
- ^ "Andromeda involved in galactic collision". MSNBC. 2007-01-29. Archived from the original on 31 August 2014. Retrieved 2014-10-07.
- ^ Overbye, Denis (September 16, 2015). "More Evidence for Coming Black Hole Collision". The New York Times.
- ^ "Astronomers solve the 60-year mystery of quasars – the most powerful objects in the Universe" (Press release). University of Sheffield. 2023-04-26. Retrieved 2023-09-10.
- Bibcode:2006S&T...112d..30D. Archived from the original(PDF) on 2015-08-24. Retrieved 2014-10-06.
- ^ Jonkler, Peter (November 6, 2013). "Unique SOS Signal from Torn Apart Star Points to Medium-Size Black Hole". Astrophysics. Radboud University. Archived from the original on August 9, 2018. Retrieved August 13, 2017.
- ^ a b Cain, Fraser (2007). "When Our Galaxy Smashes Into Andromeda, What Happens to the Sun?". Universe Today. Archived from the original on 17 May 2007. Retrieved 2007-05-16.
- ^ S2CID 14964036.
- S2CID 10073988.
- ^ Carrington, D. (2000-02-21). "Date set for desert Earth". BBC News. Archived from the original on 12 July 2014. Retrieved 2007-03-31.
- ^ "Milkomeda, Our Future Home". Harvard–Smithsonian Center for Astrophysics. 2008-05-27. Archived from the original on 2015-09-28. Retrieved 2015-09-27.
- S2CID 716993.
- S2CID 12173790.
External links
- Merrifield, Michael. "Milky Way vs Andromeda: The ultimate head-on crash". Deep Space Videos. Brady Haran.