solar cycle 10
{{Infobox Solar cycles
|cycle_num=10
|image=Carrington Richard drawing of 1859 sunspots.jpeg
|caption=Sunspots during solar cycle 10, as sketched by Richard Carrington (September 1, 1859).
|start_date=December 1855
|end_date=March 1867
|duration=11.3
|max_count=186.2
|max_count_date=February 1860
|min_count=6.0
|spotless_count=406
|prev_name=Solar cycle 9
|prev_dates=1843-1855
|next_name=Solar cycle 11
|next_dates=1867-1878}}
File:404 of 'Physiography ... New edition' (11091816093).jpg
Solar cycle 10 was the tenth solar cycle since 1755, when extensive recording of solar sunspot activity began.Kane, R.P. (2002). "[https://doi.org/10.1023%2FA%3A1014296529097 Some Implications Using the Group Sunspot Number Reconstruction]". Solar Physics 205(2), 383-401.{{cite web | title=The Sun: Did You Say the Sun Has Spots? | url=http://www.spacetoday.org/SolSys/Sun/Sunspots.html | publisher=Space Today Online | accessdate=12 August 2010}} The solar cycle lasted 11.3 years, beginning in December 1855 and ending in March 1867. The maximum smoothed sunspot number observed during the solar cycle was 186.2 (February 1860), and the starting minimum was 6.0.SIDC Monthly Smoothed Sunspot Number. "[http://sidc.oma.be/sunspot-data/]" During the transit from solar cycle 10 to 11, there were a total of 406 days without sunspots.Spotless Days. "[http://spaceweather.com/glossary/spotlessdays.htm?PHPSESSID=dli444kmrjgre0rjq6l86fv144]"What's Wrong with the Sun? (Nothing) more information: Spotless Days. "{{cite web |url=https://science.nasa.gov/headlines/y2008/11jul_solarcycleupdate.htm |title=NASA - What's Wrong with the Sun? |accessdate=2017-07-12 |url-status=dead |archiveurl=https://web.archive.org/web/20080714032353/https://science.nasa.gov/headlines/y2008/11jul_solarcycleupdate.htm |archivedate=2008-07-14 }}"Solaemon's Spotless Days Page. "[http://users.telenet.be/j.janssens/Spotless/Spotless.html]"
The first observations of solar flares occurred during this cycle.
Solar storm of 1859
{{main|Carrington Event}}
On September 1, 1859, the first solar flare was observed independently by Richard Carrington and Richard Hodgson.{{cite journal |last1=Odenwald |first1=Sten F. |author-link=Sten Odenwald |last2=Green |first2=James L. |author2-link=James L. Green |title=Bracing the Satellite Infrastructure for a Solar Superstorm |journal=Scientific American |date=28 July 2008 |doi=10.1038/scientificamerican0808-80 |doi-broken-date=18 April 2025 |url=https://www.scientificamerican.com/article/bracing-for-a-solar-superstorm/|accessdate=4 April 2018}}
On September 1–2, 1859, the largest recorded geomagnetic storm occurred in what would be known as the Carrington Event.[https://science.nasa.gov/headlines/y2009/21jan_severespaceweather.htm?list5029 "NASA — Severe Space Weather".] Aurorae were seen around the world, even over the Caribbean; those over the Rocky Mountains were so bright that their glow awoke gold miners, who began preparing breakfast because they thought it was morning.[http://www.sciam.com/article.cfm?id=timeline-the-1859-solar-superstorm "Timeline: The 1859 Solar Superstorm".] Telegraph systems all over Europe and North America failed.[http://www.space.com/scienceastronomy/mystery_monday_031027.html "The Great Storm: Solar Tempest of 1859 Revealed".] Telegraph pylons threw sparks and telegraph paper spontaneously caught fire. Some telegraph systems continued to send and receive messages despite having been disconnected from their power supplies.