On This Day

Best view of Halley's Comet in 2,000 years

Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing every 72–80 years, though with the majority of recorded apparitions (25 of 30)...

Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing every 72–80 years, though with the majority of recorded apparitions (25 of 30) occurring after 75–77 years. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Officially designated 1P/Halley, it is also commonly called Comet Halley, or sometimes simply Halley. Halley's periodic returns to the inner Solar System have been observed and recorded by astronomers around the world since at least 240 BC, but it was not until 1705 that the English astronomer Edmond Halley understood that these appearances were re-appearances of the same comet.

Historical Significance

Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing every 72–80 years, though with the majority of recorded apparitions (25 of 30) occurring after 75–77 years.

Events Before

  1. Pope Gregory IV decrees All Saints Day a holy day of obligation for the Catholic religion

    Pope Gregory IV decrees All Saints Day a holy day of obligation for the Catholic religion

  2. Chinese Emperor Wenzong conspires with chancellor Li Xun and general Zheng Zhu to kill all the eunuchs, but the plot is

    Chinese Emperor Wenzong conspires with chancellor Li Xun and general Zheng Zhu to kill all the eunuchs, but the plot is foiled. Also known as the Sweet Dew Incident

  3. Pactum Sicardi is signed, a peace agreement between the Principality of Benevento and the Duchy of Naples

    Pactum Sicardi is signed, a peace agreement between the Principality of Benevento and the Duchy of Naples

Events After

  1. Battle at Fontenay: Louis & Charles beat their brother Lotharius I

    Battle at Fontenay: Louis & Charles beat their brother Lotharius I

  2. Charles II and Louis the German sign the Oaths of Strasbourg, a pact uniting their armies in the fight against their old

    Charles II and Louis the German sign the Oaths of Strasbourg, a pact uniting their armies in the fight against their older brother Lothar

  3. Medieval Iconoclastic Controversy ends as a council in Constantinople formally reinstates the veneration of icons in chu

    Medieval Iconoclastic Controversy ends as a council in Constantinople formally reinstates the veneration of icons in churches

  4. Icon veneration officially re-instated in Hagia Sophia Cathedral in Constantinople

    Icon veneration officially re-instated in Hagia Sophia Cathedral in Constantinople

  5. Vikings sail up the Loire with 67 ships and destroy Frankish-held city of Nantes

    Vikings sail up the Loire with 67 ships and destroy Frankish-held city of Nantes

More from the 830s

Frequently Asked Questions

What happened on April 13, 837?
Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing every 72–80 years, though with the majority of recorded apparitions (25 of 30) occurring after 75–77 years. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Officially designated 1P/Halley, it is also commonly called Comet Halley, or sometimes simply Halley.
Why is Best view of Halley's Comet in 2,000 years significant?
Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing every 72–80 years, though with the majority of recorded apparitions (25 of 30) occurring after 75–77 years.

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