Some notable dates in the far future

Compiled below is a selection of estimated dates for some events given certain assumptions in the evolution of Earth, the Solar System, and the Universe. Most events are of an astronomical and cosmological nature though some are geological. A more complete list from which the ones included here were taken can be found on Wikipedia.
In 10,000 years - The end of humanity, according to Brandon Carter’s Doomsday argument, which assumes that half of the humans who will ever have lived have already been born.^[3]

In 50,000 years - Niagara Falls erodes away the remaining 20 miles to Lake Erie and ceases to exist.^[6]

In 500,000 years - By this time Earth will have likely been impacted by a meteorite of roughly 1 km in diameter.^[9]

In 1 million years - Highest estimated time until the red supergiant star Betelgeuse explodes in a supernova. The explosion is expected to be easily visible in daylight.^[10]^[11]

In 50 million years - The Californian coast begins to be subducted into the Aleutian Trench^[15]
Africa will have collided with Eurasia, closing the Mediterranean Basin and creating a mountain range similar to the Himalayas.^[16]

In ~240 million years - From its present position, the Solar System will have completed one full orbit of the Galactic center.^[18]

In 250 million years - All the continents on Earth fuse into a possible new supercontinent.^[19]^[20]

In 1 billion years - The Sun’s luminosity increases by 10%, causing Earth’s surface temperatures to reach an average of 47°C and the oceans to boil away.^[22]

In 1.5 billion years - The Sun’s circumstellar habitable zone moves outwards as its increased luminosity causes carbon dioxide to increase in Mars’s atmosphere, raising its surface temperature to levels akin to Earth during the ice age.^[23]

In 5.4 billion years - The Sun becomes a red giant.^[29]Mercury, Venus and possibly Earth are destroyed.^[30]
In 7 billion years - Collision between the Milky Way and Andromeda galaxies.^[32]

In 14.4 billion years - Sun becomes a black dwarf as its luminosity falls below three trillionths its current level, while its temperature falls to 2239 K, making it invisible to human eyes.^[36]

In 20 billion years - The end of the Universe in the Big Rip scenario.^[37] Observations of galaxy cluster speeds by the Chandra X-Ray Observatory suggest that this will not occur.^[38]

In 100 billion years - The Universe’s expansion causes all evidence of the Big Bang to disappear beyond the practical observational limit, rendering cosmology impossible.^[41]

In 10¹² (1 trillion) years - Low estimate for the time until star formation ends in galaxies as galaxies are depleted of the gas clouds they need to form stars.^[43]^,
In 2×10¹² (2 trillion) years - All galaxies outside the Local Supercluster are no longer detectable in any way, assuming that dark energy continues to make the Universe expand at an accelerating rate.^[44]

In 10¹⁵ (1 quadrillion) years - Estimated time until stellar close encounters detach all planets in the Solar System from their orbits.^[43]
By this time, the Sun will have cooled to five degrees above absolute zero.^[47]
In 3×10⁴³ years - Estimated time for all nucleons in the observable Universe to decay, if the proton half-life takes the largest possible value, 10⁴¹ years,^[43] assuming that the Big Bang was inflationary and that the same process that made baryons predominate over anti-baryons in the early Universe makes protons decay.^[53] By this time, if protons do decay, the Black Hole Era, in which black holes are the only remaining celestial objects, begins.^[46]^[43]

In 10⁶⁵ years - Assuming that protons do not decay, estimated time for rigid objects like rocks to rearrange their atoms and molecules via quantum tunneling. On this timescale all matter is liquid.^[49]

In 1.7×10¹⁰⁶ years - Estimated time until a supermassive black hole with a mass of 20 trillion solar masses decays by the Hawking process.^[54] This marks the end of the Black Hole Era. Beyond this time, if protons do decay, the Universe enters the Dark Era, in which all physical objects have decayed to subatomic particles, gradually winding down to their final energy state.^[46]^[43]

In $10^{10^{50}}$ years - Estimated time for a Boltzmann brain to appear in the vacuum via a spontaneous entropy decrease.^[55]

In $10^{10^{56}}$ years - Estimated time for random quantum fluctuations to generate a new Big Bang, according to Caroll and Chen.^[56]

In $10^{10^{10^{76.66}}}$ years - Scale of an estimated Poincaré recurrence time for the quantum state of a hypothetical box containing an isolated black hole of stellar mass.^[57] This time assumes a statistical model subject to Poincaré recurrence. A much simplified way of thinking about this time is that in a model in which history repeats itself arbitrarily many times due to properties of statistical mechanics, this is the time scale when it will first be somewhat similar (for a reasonable choice of “similar”) to its current state again.