American author Mark Twain was born and died on the days Halley's Comet passed Earth.
Judgement: 
Halley's perihelion, the comet's closest approach to the Sun, occurred in 1835 and 1910, the years of Twain's birth and death.
What is not true:The comet was not at its closest point to Earth on the days Twain was born and died.
Details about the death of the literary icon are known social media often pointing to the coincidence of Twain's birth and death with the passing of the periodic comet, like this shared with X (formerly Twitter) on February 22, 2024:
Mark Twain was born on the day Halley's Comet flew past Earth. He said, "I came in with Halley's Comet in 1835. Next year it comes again, and I expect to go out with it." Halley's Comet next appeared on April 21, 1910, the day Mark Twain died. pic.twitter.com/grAUfEwkUU
- Eli 🐔 (@hollow_maven) February 22, 2024
Halley's perihelion-the closest approach to the sun-occurred in 1835 and 1910, the years of Twain's birth and death. But the comet was not at its closest point to Earth on the days Twain was born and died, as implied by the claim that the comet "flew" past the planet on those dates. For this reason, we have rated this claim as a 'mixture'.
Snopes spoke with NASA's chief historian which referred our newsroom to an October 14, 2021 article titled " 955 years ago: Halley's Comet and the Battle of Hastings ." In it, John Uri of the Johnson Space Center wrote:
The story continues
In an interesting historical quirk, American writer Mark Twain, born two weeks after the comet's perihelion in 1835, died the day after its perihelion in 1910.
According to The Mark Twain House and Museum the American author, whose given name was Samuel Clemens, was born in Florida, Missouri, on November 30, 1835. He died on April 21, 1910 at the age of 74. The museum took notice that Twain "was born and died in the years in which Halley's Comet passed the Earth" - not the dates when he was closest.
Halley reported his perihelion November 16, 1835 and data published by NASA's Jet Propulsion Laboratory shows that the comet's next perihelion is at April 20, 1910 - the day before Twain died.
Because comets are subject to the laws of physics, it can take days, weeks or even longer for them to pass by Earth. News reports from 1910 suggest that Halley's Comet was most visible in the US between May 18 and 20, although Wired reported that the comet was at its brightest from May 14 to 22. That Halley was so visible during this time frame suggests that the comet was closest. point to the earth, also called perigee. Anyway, this happened about a month after Twain died.
Halley's 1910 passage was especially newsworthy because "newspaper predictions about the impact of Halley's Comet led to public fear and mass hysteria," the Library of Congress wrote. Before the comet arrived, some scientists reportedly said that cyan gas in its tail could end all life on Earth, sparking public concern about the "end of the world."
I came in with Halley's Comet in 1835. It will come again next year, and I expect to go out with it. It will be the biggest disappointment of my life if I don't go out with Halley's Comet. The Almighty has said without a doubt, "Here are these two inexplicable freaks; they came in together, they must go out together." Oh, I'm looking forward to that.
Sources:
1P/Halley - NASA Science. https://science.nasa.gov/solar-system/comets/1p-halley/. Accessed February 28, 2024.
955 Years Ago: Halley's Comet and the Battle of Hastings - NASA. October 14, 2021, https://www.nasa.gov/history/955-years-ago-halleys-comet-and-the-battle-of-hastings/.
1909Obs....32..175L Page 175. https://adsabs.harvard.edu/full/1909Obs....32..175L#:~:text=1835)%20was%20first%20detected%20by,(1773)%20at%20176%20Gorrespondence. Accessed February 28, 2024.
Biography - Mark Twain House. June 5, 2017, https://marktwainhouse.org/about/mark-twain/biography/, https://marktwainhouse.org/about/mark-twain/biography/.
Comets - NASA Science. https://science.nasa.gov/solar-system/comets/. Accessed February 28, 2024.
Great comets in history. https://ssd.jpl.nasa.gov/sb/great_comets.html. Accessed February 28, 2024.
Halley, Edmond. A summary of the astronomy of comets. 1705, https://library.si.edu/digital-library/book/synopsisofastron00hall.
" https://Twitter.Com/Hollow_maven/Status/1760766068149096549." X (formerly Twitter), https://twitter.com/hollow_maven/status/1760766068149096549. Accessed February 28, 2024.
" https://Twitter.Com/Rainmaker1973/Status/1760641993233818058." X (formerly Twitter), https://twitter.com/Rainmaker1973/status/1760641993233818058. Accessed February 28, 2024.
"Is it true that Mark Twain was both born and died on the same day that Halley's Comet passed over Earth?" Quora, https://www.quora.com/Is-it-true-that-Mark-Twain-was-both-born-and-died-on-the-same-day-that-Halleys-comet-passed-Earth . Accessed February 28, 2024.
"Mark Twain's Strange But Perfect Ending." PBS News Hour April 21, 2022, https://www.pbs.org/newshour/health/mark-twains-weird-but-perfect-ending.
NASA History Bureau - NASA. https://www.nasa.gov/history/history-office/. Accessed February 28, 2024.
Pop culture influence - Mark Twain House. June 5, 2017, https://marktwainhouse.org/about/mark-twain/pop-culture-influence/, https://marktwainhouse.org/about/mark-twain/pop-culture-influence/.
