Total Solar Eclipse of April 30, 1688 http://eclipse.gsfc.nasa.gov/SEsearch/SEsearchmap.php?Ecl=16880430
Walpurgis Night (Walpurgisnacht) is a traditional spring festival on 30 April or 1 May.http://en.wikipedia.org/wiki/Walpurgis_NightBeltane Fire Festival is an annual event held on April 30 on Calton Hill in Edinburgh.http://en.wikipedia.org/wiki/Beltane_Fire_Festival
The Xochicalco observatory is a cave modified to allow study of the movement of the sun.http://en.wikipedia.org/wiki/Xochicalco#Astronomical_observatory
The electron was discovered by Joseph John Thomson on the 30th April 1897https://en.wikipedia.org/wiki/J._J._Thomson#Discovery_of_the_electron
The Novara Expedition (1857-1859) was the first around-the-world mission of the Austrian Imperial war navyhttp://en.wikipedia.org/wiki/Novara_Expedition#Novara_ExpeditionSoviet submarine K-19 official commissioning took place on 30 April 1961. http://astronomy.activeboard.com/t42591037/soviet-submarine-k-19/
BeppoSAX was an ItalianDutch satellite for X-ray astronomy launched on the 30th April 1996http://en.wikipedia.org/wiki/Beppo_SaxOn April 30, 1997, USRA purchased the aircraft N145UA for use as an airborne observatoryhttp://en.wikipedia.org/wiki/Stratospheric_Observatory_for_Infrared_Astronomy
Duane Gene "Digger" Carey (Born April 30, 1957) is a former NASA astronaut.http://en.wikipedia.org/wiki/Duane_G._CareyMichael John Smith (April 30, 1945-January 28, 1986) was an American astronaut-pilot http://astronomy.activeboard.com/t48937342/michael-smith-1945-1986/Johann Carl Friedrich Gauss (30 April 1777 - 23 February 1855) was a German mathematicianhttp://en.wikipedia.org/wiki/Carl_Friedrich_GaussRobert Endre Tarjan (born April 30, 1948) is an American computer scientist.http://en.wikipedia.org/wiki/Robert_TarjanJohann Karl Burckhardt (April 30, 1773 - June 22, 1825) was a German-born astronomerhttp://en.wikipedia.org/wiki/Johann_Karl_BurckhardtGeorge W. Myers (April 30, 1864 - November 23, 1931) was an American astronomerhttp://en.wikipedia.org/wiki/George_W._Myers
The Tomorrow People is a British children's science fiction television series,http://astronomy.activeboard.com/t48937368/the-tomorrow-people/
NGC 1724 was discovered by George Friedrich Wilhelm Rümker on the 30th April 1864.http://astronomy.activeboard.com/t57432257/ngc-1724/
NGC 2824 was discovered by Heinrich Louis d'Arrest on the 30th April 1864.http://astronomy.activeboard.com/t60109071/ngc-2824/
NGC 3012 was discovered by Heinrich Louis d'Arrest on the 30th April 1862.http://astronomy.activeboard.com/t60109085/ngc-3012/
NGC 3042 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109108/ngc-3042/
NGC 3126 was discovered by Heinrich Louis d'Arrest on the 30th April 1864.http://astronomy.activeboard.com/t60109095/ngc-3126/
NGC 4103 was discovered by James Dunlop on the 30th April 1826. http://astronomy.activeboard.com/t60109274/ngc-4103/
NGC 4600 was discovered by William Herschel on the 30th April 1786.http://astronomy.activeboard.com/t60109237/ngc-4600/NGC 4701 was discovered by William Herschel on the 30th April 1786.http://astronomy.activeboard.com/t57432242/ngc-4701/NGC 4852 was discovered by James Dunlop on the 30th April 1826.http://astronomy.activeboard.com/t57432223/ngc-4852/NGC 4900 was discovered by William Herschel on the 30th April 1786.http://astronomy.activeboard.com/t57432206/ngc-4900/
NGC 4991 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109119/ngc-4991/
NGC 5013 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109131/ngc-5013/
NGC 5050 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109138/ngc-5050/
NGC 5148 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109146/ngc-5148/
NGC 5159 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109157/ngc-5159/
NGC 5200 was discovered by Phillip Sydney Coolidge on the 30th April 1859.http://astronomy.activeboard.com/t57432196/ngc-5200/
NGC 5213 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109190/ngc-5213/
NGC 5231 was discovered byAlbert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109197/ngc-5231/
NGC 5245 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109204/ngc-5245/
NGC 5246 was discovered by Albert Marth on the 30th April 1864.http://astronomy.activeboard.com/t60109216/ngc-5246/
NGC 5560 was discovered by William Herschel on the 30th April 1786.http://astronomy.activeboard.com/t63403857/ngc-5560/NGC 5566 was discovered by William Herschel on the 30th April 1786.http://astronomy.activeboard.com/t57432187/ngc-5566/NGC 5690 was discovered by William Herschel on the 30th April 1786.http://astronomy.activeboard.com/t57432166/ngc-5690/
Supernova 1006 first appeared in the constellation of Lupus between April 30 and May 1 of that yearhttp://astronomy.activeboard.com/t5103277/sn1006/
Title: Radio echo observations of Venus and Mercury at 23 CM wavelengthAuthors: Evans, J. V., Brockelman, R. A., Henry, J. C., Hyde, G. M., Kraft, L. G., Reid, W. A., , http://adsabs.harvard.edu/full/1965AJ.....70..486E
Asteroid (753) Tiflis was discovered by G. N. Neujmin on the 30th April 1913http://en.wikipedia.org/wiki/753_Tiflis
PIA08429: Impact Craters on Xanadu http://photojournal.jpl.nasa.gov/catalog/PIA08429On April 30, 2013, an asteroid exploded with an impact energy of 1020 kilotons over the North Atlantic Oceanhttps://www.treehugger.com/natural-sciences/nuclear-explosion-detection-system-tells-us-how-many-big-asteroids-hit-earth-scary.html
MeteoritesThe Queen's Mercy (H6) meteorite fell in Eastern Cape, South Africa, on the 30th April, 1925.http://astronomy.activeboard.com/t48937380/queens-mercy-meteorite/The Sabrum (LL6) meteorite fell in Tripura, India, on the 30th April, 1999.http://astronomy.activeboard.com/t48937385/sabrum-meteorite/The Soltmany (L6 chondrite) meteorite fell in Poland, on the 30th April, 2011.http://astronomy.activeboard.com/t42667274/so322tmany-meteorite/