if the universe is expanding, why are we on a collision course with the andromeda galaxy?

by Concepcion Buckridge 3 min read

If the universe is expanding, why is the galaxy Andromeda on a collision course with our Milky Way Galaxy? Because the speed with which the Andromeda and the Milky Way are headed towards each other is greater than the speed of the expansion of the universe between them. 0 Replies

While stars in both the Milky Way and Andromeda
Milky Way and Andromeda
The Andromeda–Milky Way collision is a galactic collision predicted to occur in about 4.5 billion years between the two largest galaxies in the Local Group—the Milky Way (which contains the Solar System and Earth) and the Andromeda Galaxy.
https://en.wikipedia.org › Andromeda–Milky_Way_collision
are unlikely to collide due to their great distances, the gravitational disturbance could cause what is left of our Solar System to change its position – tossing it from its current position in the Orion spur and further from the Milky Way's core.
Jan 26, 2013

Full Answer

What will happen when the Milky Way collides with Andromeda?

NASA astronomers announced Thursday they can now predict with certainty the next major cosmic event to affect our galaxy, sun, and solar system: the titanic collision of our Milky Way galaxy with the neighboring Andromeda galaxy. The Milky Way is destined to get a major makeover during the encounter, which is predicted to happen four...

Is the universe expanding and accelerating?

Also shown is a smaller galaxy, Triangulum, which may be part of the smashup. The universe is expanding and accelerating, and collisions between galaxies in close proximity to each other still happen because they are bound by the gravity of the dark matter surrounding them.

What will happen when two galaxies collide?

Although the galaxies will plow into each other, stars inside each galaxy are so far apart that they will not collide with other stars during the encounter. However, the stars will be thrown into different orbits around the new galactic center.

Why is the local group of galaxies not expanding?

The universe is expanding. The Local Group of galaxies is not. It is a gravitationally bound structure. Let me explain. The early universe was filled pretty much uniformly with gas that was expanding everywhere. However, it had small “density perturbations”: In some places, it was a little denser, in some places it was a little less dense.

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Why will Andromeda and Milky Way collide if universe is expanding?

The strong gravitational attraction between the Milky Way and Andromeda wins out over the dark energy attempting to drive them apart, and will ultimately cause a collision to occur.

What will happen to us when the Milky Way and Andromeda collide?

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. They also predict a 12% chance that the Solar System will be ejected from the new galaxy sometime during the collision.

Will humans survive the Milky Way Andromeda collision?

Luckily, experts think that Earth will survive, but it won't be entirely unaffected. The collision will unfold right in front of us, changing the night sky to look like nothing any human has seen before.

What will happen to our galaxy when it collides with Andromeda in the future?

The result of the collision between Andromeda and the Milky Way will be a new, larger galaxy, but rather than being a spiral like its forebears, this new system ends up as a giant elliptical. The authors of the paper in question have named this new galaxy 'Milkdromeda'.

Can Andromeda destroy Earth?

"I think it's unlikely the Earth will be physically destroyed by the collision with Andromeda," Mackey said. "It's not out of the question, but in general the stars in galaxies are spaced sufficiently sparsely that direct collisions between stars are rare.

Will the Andromeda collision affect Earth?

Project AMIGA of the Hubble Space Telescope did exactly that and found out the true extent of Andromeda. What it also told us shockingly, is that the collision predicted for 4.5 billion years later by NASA, is happening right now. This will affect the Earth and our entire solar system.

How many years until the sun dies?

five billionStars like our Sun burn for about nine or 10 billion years. So our Sun is about halfway through its life. But don't worry. It still has about 5,000,000,000—five billion—years to go.

Does Star Trek ever leave the galaxy?

A reminder about the vastness of space: the bulk of Star Trek's adventures don't even leave our galaxy.

What will happen when the Milky Way collides with Andromeda galaxy in 5 billion years?

Perhaps we'll have left Earth, and even our solar system. We may still get the view of Andromeda crashing into the Milky Way, just from a slightly different perspective. Bottom line: The Milky Way and Andromeda merger has already begun. The two spiral galaxies will form one giant elliptical galaxy in 5 billion years.

Is our galaxy on a collision course?

Perhaps the most well-known collision in the Milky Way's neighborhood has yet to happen. The massive Andromeda Galaxy, also known as M31, will smash into us in about 4 billion years.

Why is the Andromeda galaxy moving toward us?

Answer: The Andromeda and Milky Way galaxies are moving toward each other due to mutual gravitational attraction. This mutual gravity force is stronger than the force which causes the expansion of the Universe on the relatively short distances between Andromeda and the Milky Way.

Why do galaxies collide?

Many large galaxies can attract a smaller galaxy. The gravity of the large galaxy will pull the smaller one towards it, creating a collision. If one galaxy has enough momentum, the galaxy with enough movement or momentum could keep moving away after the collision.

What galaxy is the collision path of?

This illustration shows the collision paths of our Milky Way galaxy and the Andromeda galaxy. The galaxies are moving toward each other under the inexorable pull of gravity between them. Also shown is a smaller galaxy, Triangulum, which may be part of the smashup. Credits: NASA; ESA; A. Feild and R. van der Marel, STScI.

How long will it take for the Milky Way and Andromeda to merge?

Hubble Space Telescope observations indicate that the two galaxies, pulled together by their mutual gravity, will crash together about 4 billion years from now. Around 6 billion years from now, the two galaxies will merge to form a single galaxy.

How did Hubble measure the distance of the Milky Way?

Edwin Hubble measured its vast distance by uncovering a variable star that served as a "milepost marker.". Hubble went on to discover the expanding universe where galaxies are rushing away from us, but it has long been known that M31 is moving toward the Milky Way at about 250,000 miles per hour.

Which galaxy will join the M31/Milky Way?

To make matters more complicated, M31's small companion, the Triangulum galaxy , M33, will join in the collision and perhaps later merge with the M31/Milky Way pair.

When will the Milky Way get a major makeover?

The Milky Way is destined to get a major makeover during the encounter, which is predicted to happen four billion years from now. It is likely the sun will be flung into a new region of our galaxy, but our Earth and solar system are in no danger of being destroyed. This illustration shows a stage in the predicted merger between our Milky Way galaxy ...

When will the two galaxies merge?

Around 6 billion years from now, the two galaxies will merge to form a single galaxy. The video also shows the Triangulum galaxy, which will join in the collision and perhaps later merge with the Andromeda/Milky Way pair.

Is the Milky Way destined for a collision?

NASA's Hubble Shows Milky Way is Destined for Head-On Collision. NASA astronomers announced Thursday they can now predict with certainty the next major cosmic event to affect our galaxy, sun, and solar system: the titanic collision of our Milky Way galaxy with the neighboring Andromeda galaxy. The Milky Way is destined to get a major makeover ...

What was the early universe filled with?

The early universe was filled pretty much uniformly with gas that was expanding everywhere. However, it had small “density perturbations”: In some places, it was a little denser, in some places it was a little less dense. Wherever it was denser, it had more gravity. Gravity that was pulling it together. If the density was high enough, gravity was ...

Do clusters of galaxies expand?

So clusters of galaxies do not individually expand, but clusters of galaxies do still fly apart from each other everywhere. Having said that, there is also a degree ...

Is M86 still gravitationally bound?

So there is M86, for instance, a member of the Virgo cluster that happens to be moving toward the Milky Way at the moment. It is still gravitationally bound within Virgo, and a few billion years from now, it will be receding from us just as rapidly as it is in a different segment of its trajectory within Virgo.