Spicule ( solar physics ) - wikipedia Spicule ( solar physics ) Spicules, visible as dark tubes. Solar active region 10380, June 2004 In solar physics, a spicule is a dynamic jet of about 500 km diameter in the chromosphere of the Sun. It moves upwards at about 20 km / s from the photosphere. They were discovered in 1877 by Father Angelo Secchi of the Observatory of Roman Collegium in Rome. Contents 1 Description 2 Prevalence 3 Causes 4 References 5 Literature 6 External links Description Spicules last for about 15 minutes ; at the solar limb they appear elongated ( if seen on the disk, they are known as `` mottles '' or `` fibrils '' ). They are usually associated with regions of high magnetic flux ; their mass flux is about 100 times that of the solar wind. They rise at a rate of 20 km / s ( or 72,000 km / h ) and can reach several thousand kilometers in height before collapsing and fading away. Prevalence There are about 300,000 active spicules at any one time on the Sun 's chromosphere, amounting to about 1 % of the Sun 's surface. An individual spicule typically reaches 3,000 - 10,000 km altitude above the photosphere. Causes Bart De Pontieu ( Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, California, United States ), Robert Erdélyi and Stewart James ( both from the University of Sheffield, United Kingdom ) hypothesised in 2004 that spicules formed as a result of P - mode oscillations in the Sun 's surface, sound waves with a period of about five minutes that causes the Sun 's surface to rise and fall at several hundred meters per second ( see helioseismology ). Magnetic flux tubes that tilted away from the vertical can focus and guide the rising material up into the solar atmosphere to form a spicule. There is still however some controversy about the issue in the solar physics community. References ^ Jump up to : Freedman, Roger A. ; Kaufmann III, William J. ( 2008 ). Universe. New York, USA : W.H. Freeman and Company. p. 762. ISBN 978 - 0 - 7167 - 8584 - 2. Jump up ^ § 1, Two Dynamical Models for Solar Spicules, Paul Lorrain and Serge Koutchmy, Solar Physics 165, # 1 ( April 1996 ), pp. 115 -- 137, doi : 10.1007 / BF00149093, Bibcode : 1996SoPh... 165... 115L. Literature De Pontieu, B., Erdélyi, R. and James, S : Solar chromospheric spicules from the leakage of photospheric oscillations and flows In : Nature. 430 / 2004, p. 536 -- 539, ISSN 0028 - 0836 External links NASA Astronomy Picture of the Day : Spicules : Jets on the Sun ( 2 November 2008 ) The Sun Internal structure Core Radiation zone Tachocline Convection zone Atmosphere Photosphere Supergranulation Granule Faculae Sunspot Chromosphere Plage Spicule Moreton wave Corona Transition region Coronal hole Coronal loop Coronal mass ejection Prominence Helmet streamer Supra - arcade downflows Variation Solar cycle List of solar cycles Solar maximum Solar minimum Wolf number Solar wind Flare Helioseismology Heliosphere Current sheet Termination shock Heliosheath Heliopause Bow shock Related topics Heliophysics Solar activity Solar astronomy Solar dynamo Eclipse Solar energy Solar neutrino Solar observation Solar phenomena Solar physics Solar System Solar telescope Solar time Space weather Standard solar model Radiation Spectral class : G2V Retrieved from `` https://en.wikipedia.org/w/index.php?title=Spicule_(solar_physics)&oldid=811898618 '' Categories : Solar phenomena Talk Contents About Wikipedia Беларуская Català Čeština Deutsch Español Français 한국어 Hrvatski Italiano Lëtzebuergesch Nederlands 日本 語 Norsk Norsk nynorsk Polski Português Română Русский Slovenčina Српски / srpski Srpskohrvatski / српскохрватски Svenska ไทย Türkçe Українська 中文 Edit links This page was last edited on 24 November 2017, at 19 : 28. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: where do spicules tend to occur on the sun
Answer: the chromosphere