# Are there any stars that one day we could collide with?

I'm not talking about tomorrow but in the far far future could we say our Sun could collide with another star or otherwise within our current detectable range?

• if there was a galaxy of melons in the sky about 2-7 kilometers average distance, how often would 2 of them collide. if you add the number of melons that you can fit on a 4.5 kilometer diameter sphere, the chance of the planet hitting another star in the coming million years is about 1/the total number of melons. – aliential Oct 3 '18 at 22:40
• Wikipedia lists a number of past and future close approachs, which "close" being relative. The closest listed will be about $\frac 1 6$ of a light year in about 1.2 million years from now. – StephenG Oct 4 '18 at 0:13
• This is slightly related visualisation of galaxy density though it refers to the center of the galaxy where the star density is much higher than here, and I think there may be another Q&A of this type here or in a related SE site but I haven't found it yet. – uhoh Oct 4 '18 at 4:50
• Depends on whether there's enough mass (dark or otherwise) to cause the universe to collapse back into a singularity. – Carl Witthoft Oct 4 '18 at 18:48
• Imagine a cherry in Portland and another in Montreal. So rates the distance of the stars, compared to their sizes. – peterh - Reinstate Monica Oct 4 '18 at 20:53

Statistically speaking, the Sun will probably not crash into any other stars in the near future. Currently, we do not believe the Sun is on a collision course with any other star either, but we can only predict so far due to Chaos Theory and what I believe is called Lyapunov Time.

The reason for this is that solar systemic distances are minuscule compared to interstellar distances. The distance from the Earth to the Sun is 1 AU, or 150,000,000 km. Our sun is 0.004 AU in radius. The nearest star (which isn't on a collision course) is approximately 275,000 AU from the Sun. As you can see stars are generally far apart, and thus they rarely interact.

The locations of the stars do, in fact, change over hundreds of thousands of years, but again, stars generally stay far apart. That is not to say that stars never collide. However, it only happens in very dense globular clusters, young star systems (where they may form close), and in contact stars, as well as the occasional exception, which may be 1-2 in the entire galaxy when Andromeda collides with our Milky Way Galaxy in a few billion years (the Sun might already be dead though).

Currently there are no stars in our vicinity that will enter the solar system or even collide with the sun in the, astronomically speaking, near future. Calculations can only be made for a limited time as they become more and more uncertain to more we look into the future but maybe this diagram is helpful for you which depicts the distance of some of our closests stellar neighbors over the next 80000 years.

Coincidentially I stumbled over a Wikipedia article about Gliese 710. In 1.5 million years, this red dwarf will come very near to the Solar System, possibly even cross the Kuiper Belt. It is of course still very uncertain how close it will come but it is possible that it disturbs the orbits of object in the Oort Cloud or the Kuiper Belt and thus sends them flying towards the inner Solar System.

Although it is no collision it is as close to one as we currently know.