This series of photo illustrations shows the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. The sequence is inspired by dynamical computer modeling of the inevitable future collision between the two galaxies.
First Row, Left Panel: Present Day – This is a nighttime view of the current sky, with the bright belt of our Milky Way. The Andromeda galaxy lies 2.5 million light-years away and looks like a faint spindle, several times the diameter of the full Moon.
First Row, Right Panel: 2 Billion Years – The disk of the approaching Andromeda galaxy is noticeably larger.
Second Row, Left Panel: 3.75 Billion Years – Andromeda fills the field of view. The Milky Way begins to show distortion due to tidal pull from Andromeda.
Second Row, Right Panel, and Third Row, Left Panel: 3.85-3.9 Billion Years – During the first close approach, the sky is ablaze with new star formation, which is evident in a plethora of emission nebulae and open young star clusters.
Third Row, Right Panel: 4 Billion Years – After its first close pass, Andromeda is tidally stretched out. The Milky Way, too, becomes warped.
Fourth Row, Left Panel: 5.1 Billion Years – During the second close passage, the cores of the Milky Way and Andromeda appear as a pair of bright lobes. Star-forming nebulae are much less prominent because the interstellar gas and dust has been significantly decreased by previous bursts of star formation.
Fourth Row, Right Panel: 7 Billion Years – The merged galaxies form a huge elliptical galaxy, its bright core dominating the nighttime sky. Scoured of dust and gas, the newly merged elliptical galaxy no longer makes stars and no nebulae appear in the sky. The aging starry population is no longer concentrated along a plane, but instead fills an ellipsoidal volume.
NOTE: These illustrations depict the view from about 25,000 light-years away from the center of the Milky Way. The future view from our solar system will most likely be markedly different, depending on how the Sun's orbit within the galaxy changes during the collision.
Credits
Science Illustration: NASA, ESA, Z. Levay and R. van der Marel (STScI), T. Hallas, and A. Mellinger| About The Object | |
|---|---|
| Object Name | M31, NGC 224, Andromeda Galaxy |
| R.A. Position | 00h 42m 44.0s |
| Dec. Position | 41° 16' 8.99" |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
