On the decrease of sunspot activity and absence of severe space weather conditions during the multiple planetary conjunction periods of 1850-2000 AD
OON THE DECREASE OF SUNSPOT ACTIVITY AND ABSENCE OF SEVERE SPACE WEATHER CONDITIONS DURING THE MUTIPLE PLANETARY CONJUNCTION PERIODS OF 1850-2000 AD
Nisha.N.G and T.E.Girish
1 Department of Physics,Government College for Women,Trivandrum 695014, India 2 Department of Physics,UniversityCollege,Trivandrum 695034, India *Corresponding Author, E mail : [email protected] We have studied solar activity and space weather conditions during multiple planetary conjunction periods ( MPC) as observed from Earth during the years 1850-2000 AD. Significant decreases in sunspot activity and solar 10.7 cm radio flux and absence of severe space weather conditions is found during most of these MPC . Possible planetary influences in longitudinal organisation of sunspot activity is suggested by these results. The success of major space missions ( lunar and human) during MPC is also noticed during 1957-2000 AD. The applications of the above results include: short term space mission planning and inference/prediction of solar-terrestrial conditions during multiple planetary conjunction periods. Key words: multiple planetary conjunctions, sunspot activity, space weather, space missions
The study of planetary effects on sunspot activity is more than 150 years old (Charbonneau, 2002; Charbonneau, 2012 ) Recent research efforts focus on the understanding of possibilities of maintenance of 11 year and secular solar cycles by the planetary dynamics in the solar system . One of the earliest studies revealed that the average size of a spot would appear to attain its maximum on that side of the Sun which is turned away from Venus or from Mercury, and to have its minimum in the neighborhood of Venus or Mercury (De La Rue, et.al., 1872). Shuster (1911) studied how relative helio longitudinal organisation of sunspot activity is affected by different planets. Jose (1965) studied the importance of the periodicities involved in the motion of the Sun relative to the centre of mass of solar system and operation of the solar dynamo. Ambroz ( 1971) studied the longitudinal organization of solar activity in association with the variations in planetary tidal forces. Hung ( 2007) observed an 11 year cycle of the alignment of Venus, Earth and Jupiter similar to the 11.1 year
Schwabe’s sunspot cycle, from the daily planet positions during the period from 1840 –
Kali yuga in India. The number of days elapsed from this date is considered in ancient India (similar to Julian day in modern astronomy) to record major events in history. The 60 year cycle in the re appearance of conjunctions of large planets Jupiter and Saturn in a particular zodiacal sign was given importance in this connection. It is believed that planetary conjunctions can cause natural hazards like floods and earth quakes. However there are no explicit studies in the modern context on the different solar-terrestrial aspects of multiple planetary conjunctions in spite of the vast literature existing on the planetary effects on solar activity. In this paper, first we will specify a criteria to identify multiple planetary conjunctions (MPC) involving three planets apart from Earth using a geocentric coordinate system. The daily sunspot activity, daily sunspot area and daily solar 10.7 cm flux variations during the MPC periods are then studied for the years 1850-2000 AD depending on the availability of relevant data. The occurrence of extreme space weather events if any during MPC periods is then studied. The data on successful space missions during planetary conjunctions period is also investigated. The possible applications of the results of present studies will be discussed. This paper is a continuation of our earlier studies on this topic ( Nisha, 2003; Girish and Nisha,2012; Nisha,2015).
2. Criteria and Identification of Multiple Planetary Conjunctions
The criteria chosen for the identification of Multiple Planetary Conjunctions (MPC) in this study are : ( a) Conjunctions between five visible planets of our solar system, viz., Mercury, Venus, Mars, Jupiter and Saturn with the Sun (projection of position of Earth) are considered. (b) The co-ordinate system selected to identify the position of the Sun and planets is geocentric co-ordinate system. (c) Geocentric longitudes of the planets and Sun in conjunction should be within 20°. (d) The minimum number of planets in conjunction should be three of which one should be either Jupiter or Saturn. We have identified such 128 Multiple Planetary conjunctions satisfying the above criteria during the years 1850-2000 AD using the published values of the geocentric longitudes ( Swamikannu Pillai ,1985) of visible planets (Mercury,Venus,Mars,Jupiter and Saturn ) and the Sun ( projection of earth’s orbital motion)
3 On the decrease of sunspot activity and solar 10.7cm radio flux during Multiple Planetary conjunctions during 1850-2000 AD 3.1 Selected Examples of sunspot activity decrease
Both international sunspot number (pre-revised) and Greenwich sunspot area ( NGDC website) are considered as excellent indicators of solar activity . The variations of daily sunspot number and daily sunspot area in and around the periods of planetary conjunctions were analyzed graphically for the entire 128 conjunctions identified. Typical examples distinct sunspot activity decreases during MPC are shown in Figure 1. In 1916 July a five planet conjunction, in 1962 February a six planet conjunction and in 2000 May a five planet conjunction occurred. In each figure the period of planetary conjunction was marked as thin vertical lines and the thick vertical arrow indicate the date of closest conjunction (CCD), the day on which the planetary longitudes have a minimum separation. The planets in conjunction and their respective geocentric longitudes are given in right column of each Figure. The good correlation between the variation of both sunspot number and sunspot area is evident for each of the above MPC period. The variations of the daily solar 10.7cm radio flux ( NGDC website) during the 1962 Februrary MPC is shown in Fig 2. Solar radio flux also shows distinct decreases during planetary conjunction periods which is found to be correlated with sunspot number decreases as shown in this Figure.
Fig 1 (a) s un s p o t a r e a s un s p o t nu m b e r days; from july 01 (a) CCD - 1916 july 15 ssn ssa corr.coeff.=0.9412 Fig 1 (b) Fig 1(c) Figure 1 Variation of daily international sunspot number (R) given as solid curved line and Greenwich daily sunspot area (in units of MSH) given as dotted curved lines during selected planetary conjunction periods: (a) 1916 July (b) 1962 February and (c) 2000 May. The thin vertical lines shows the beginning and end of conjunction days and the thick vertical arrow shows closest conjunction date (CCD). s un s p o t a r e a s un s p o t nu m b e r days; from january 25 (b) CCD - 1962 february 06 ssn ssa corr.coeff=0.9037 s un s p o t a r e a s un s p o t nu m b e r days; from april 20 (c) CCD - 2000 may 05 ssn ssa corr.coeff=0.9104 Fig 2 Solar daily 10.7 cm radio flux variations during the 1962 February planetary conjunction period. The solar 10.7 cm flux changes are correlated with sunspot number ( ssn) variations during this MPC .
We could find 93 MPC with associated sunspot activity decreases out of 128 MPC studied for the years 1850-2000 AD. We classified the variations in daily sunspot number in connection with the planetary conjunctions into different categories based on the following scheme. (a) CC - the daily sunspot number shows a characteristic decrease in a narrow region around the date of closest conjunction. (Examples: In Figure 2.1 CCD – – – EC – the daily sunspot number shows a notable decrease during the entire duration of planetary conjunction period. (Examples: In Figure 2.1 CCD – CCPE – the daily sunspot number shows a notable decrease only during the early part of the conjunction period including the date of CC. (Examples: In Figure 2.1 CCD – – – CCPA – the daily sunspot number shows a notable decrease only during the later part of the conjunction period including the date of closest conjunction. (Examples: In Figure 2.1 CCD – – – NE – there is no notable change in the daily sunspot variation during the conjunction period. (Examples: In Figure 2.1 CCD – – – d a il y s un s p o t nu m b e r d a il y . c m s o l a r f l u x days; from january 24 CCD - 1962 february 06 solar fluxssn f) PE - the daily sunspot number shows a decrease only during the early part of the conjunction period excluding closest conjunction.(Examples: In Figure 2.1 CCD – – PA – the daily sunspot number shows a decrease only during the later part of the conjunction period excluding closest conjunction. (Examples: In Figure 2.1 CCD – – max is the maximum daily sunspot number just before MPC and R min is the minimum daily sunspot number during the MPC period then we define δ R as δ 𝑅 = 𝑅 𝑚𝑎𝑥 − 𝑅 𝑚𝑖𝑛 𝑅 𝑚𝑎𝑥 + 𝑅 𝑚𝑖𝑛 (1) If A max is the maximum daily sunspot area just before MPC and A min is the maximum daily sunspot area durig the MPC period then we define δ A as δ 𝐴 = 𝐴 𝑀𝑎𝑥 − 𝐴
𝑀𝑖𝑛 𝐴 𝑀𝑎𝑥 + 𝐴
𝑀𝑖𝑛 (2) If S max is the maximum daily 10.7 cm solar radio flux just before MPC and S min is the minimum daily 10.7 cm solar radio flux during the MPC period then we define δ s as δ 𝑠 = 𝑆 𝑚𝑎𝑥 − 𝑆 𝑚𝑖𝑛 𝑆 𝑚𝑎𝑥 + 𝑆 𝑚𝑖𝑛 (3) Duration of sunspot activity decrease in days during the MPC period For each of these 93 MPC we have calculated the above parameter and the results are given in Table 1 where we have also given the classification of sunspot activity decrease ( CCPA etc) , close conjunction date, planets in conjunction, maximum angular separation in geocentric longitude between the planets in conjunction . The details of δR calculations and duration of sunspot activity decrease during the MPC periods is given in Table 2. Figure 3:
Variation of daily international sunspot number (R) given as solid curved line and Greenwich daily sunspot area (in units of MSH) given as dotted curved lines during selected planetary conjunction periods for the category of PE, CCPE, PA, NE, CCPA & CC: The thin vertical lines shows the beginning and end of conjunction days and the thick vertical arrow shows closest conjunction date (CCD).
The duration of sunspot decrease during different MPC studied during the years 1850-2000 AD is found to vary between 3-22 days . The frequency of occurrences of different categories of sunspot decreases during MPC studied for the period 1850-2000 AD is given in Table 3. s un s p o t a r e a s un s p o t nu m b e r days; from march 15CCD- 1880 march 27 ssn corr.coeff.=0.7465 PE s un s p o t a r e a s un s p o t nu m b e r days; from february 01CCD - 1906 february 20 ssn corr.coeff. corr.coeff.=0.79040500100015002000050100 1 6 11 16 21 26 s un s p o t a r e a s un s p o t nu m b e r days; from february 01CCD - 1933 february 07 ssn corr.coeff=0.9713 0500100015002000250030003500050100150200250 1 6 11 16 21 26 s un s p o t a r e a s un s p o t nu m b e r days; from febraury 01 CCD - 1938 february 17 ssn corr.coeff=0.8520 s un s p o t a r e a s un s p o t nu m b e r days; from august 01CCD - 1955 august 17 ssn corr.coeff=0.9167 CCPA s un s p o t a r e a s un s p o t nu m b e r days; from october 01CCD - 1981 october 10 ssn corr.coeff=0.5013 CC . Extreme Space weather events and Multiple planetary conjunction periods during 1850-2000 AD Weak solar activity conditions are expected to be associated with calm space weather conditions even though there can be few exceptions. In the previous section it is found that there is a high probability of low sunspot activity during multiple planetary conjunction periods. In this section we will study whether occurrences of severe space weather events such as intense geomagnetic storms,intense solar flares and 30 MeV solar proton events happen during multiple planetary conjunction periods during 1850 -2000 AD. The extreme space weather event data is obtained from published literature ( Cliver and Svaalgard,2004). A list of all such severe space weather events during this long period is given in Table 4 . None of these severe space weather events are found to occur during MPC periods which is also shown in this Table.108 out of 109 extreme space weather events are not found to occur during the MPC periods.
5 Space missions and Multiple planetary conjunctions
Understanding space weather conditions is important for the operations of technological systems in space like satellites . It also helps to plan space missions and related space craft launches from Earth. Calm solar activity conditions are understood to be generally associated with calm space weather conditions even though there are exceptions. In Table 5 and Table 6 we have given list of lunar and human space flight missions associated with
MPC’s during the years 1957 -2000 AD. Out of 22 space missions associated with planetary conjunction periods only 4 failed giving a success rate of more than 80 %.
From our detailed investigations using relevant data for more than 150 years ( 1850-2000 AD) we could find that multiple planetary conjunction periods are associated with notable decreases in sunspot activity and relatively calm space weather conditions. We can use these results for solar-terrestrial prediction purposes and space mission planning. It can inspire further studies to understand its possible physical causes. This study stands apart from the previous studies on the effect of planetary dynamics on the solar activity variability. Sunspot activity decrease is observed for 70% of multiple planetary conjunctions studied during 1850-2000.The duration of this decrease range from few days to more than two weeks. The sunspot ctivity decrease is observed for MPC both during sunspot minima and maxima phases. However the magnitude of decrease shows a weak dependence on the background level of daily sunspot activity during the conjunction period. In Figure 4 we have plotted Rmax against δR . The linear regression best fit line in this plot suggest an inverse relation between two parameters inspite of the large scatter in the data points . δR becomes 100% when R min during a MPC is zero which happens generally during low sunspot activity periods. When we compare δR, δA and δSd uring different
MPC as shown in Table we find δA is highest followed by δR and δS is the least of the three. As a typical example during the close MPC which occurred during May 2000 δR is found to be 49.4 % δA is 83.4 % and δS is only 23.8 %. Generally δS values are found to be only one -third or one fourth of δA. values for typical MPC. So among the sunspot activity related parameters sunspot area shows significant decreases during the the planetary conjunction periods while solar 10.7 cm flux changes are observed to be relatively small.
Fig 4 : Linar fit between maximum sunspot number prior to MPC and percentage of sunspot number decreases during MPC for selected MPC between 1850-2000 AD
We have found the absence of extreme space weather events during the almost all multiple planetary conjunction periods during the years 1850-2000 AD. This includes occurrences of very intense geomagnetic storms, 30 MeV solar proton events and intense solar flares. which belong the category of extreme space weather activity near Earth. From an earlier study it is found that only weak to moderate intensity geomagnetic storms are likely to occur during MPC periods Some isolated 10 MeV proton events have occurred during our multiple planetary conjunction periods. We have studied the association between Lunar and human space missions during 1957-2000 and the multiple planetary conjunctions. Many of these missions which are carried out during planetary conjunction periods are found to be successful. We do not assign high statistical significance for these results. Since low sunspot activity and calm space weather conditions are most probable during y = -0.0026x + 0.886R² = 0.3424
Rmax-delta R lanetary conjunctions for future multiple planetary conjunction periods they can be considered for of short space missions in future. Results of the present study points out the possibilities of inferring solar activity and space weather conditions in the past MPC periods and predicting the same for future MPC periods. Mees paper gives the list of all MPC’s back to 3102 BC similar to the recent 1962 Feb and 2000 May close MPC events studied in this paper. The dates of all close triple planetary conjunctions during 1971-2056 AD is now available (http://stevealbers.net/albers/ast/conjun/conjun.html ). We have studied the solar/sunspot activity decreases , occurences of space weather events and human space missions during these triple planetary conjunction periods between 2002-2016 AD. The results are given in Table 7 which are almost similar to our results from our studies during 1850-2000 AD. This will provide an independent conformation of our conclusions.
7 Conclusions (i) Significant decreases in daily sunspot activity is found for majority of multiple planetary conjunction periods during 1850-2000 AD. Similar results is also found for daily solar 10.7 cm radio flux during 1958-2000 AD. The above effect is found to be independent of the phase of sunspot cycle (ii) Occurrences of extreme space weather events are found to be very rare during multiple planetary conjunction periods as evident from analysis of relevant data for the years 1850 – References
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Δ A
Δ S – Sep 18 Sun, Mar, Mer, Jup Sep-14 12.3 CC 24.64% …….. …….. …….. …….. – Nov 19 Sun, Mar, Mer, Jup Nov-15 13.9 CCPA 81.03% …….. …….. – Jun 30 Sun, Mer, Ven, Sat Jun-23 18.2 EC 100.00% …….. …….. – Apr 21 Sun, Mar, Mer, Jup Apr-17 19.7 CCPA 100.00% …….. …….. – May 11 Sun, Mer, Jup, Ven May-01 7.3 PA 80.49% …….. …….. – Jul 11 Sun, Mar, Mer, Jup Jun-21 11.7 PE 44.38% …….. …….. …….. …….. – Sep 18 Sun, Mar, Mer, Jup, Sat Sep-03 10.5 CCPA 54.44% …….. …….. …….. …….. …….. …….. – Oct 16 Sun, Mar, Mer, Sat Oct-06 10.9 CC 64.84% …….. …….. – Sep 21 Sun, Mer, Ven, Sat Sep-19 14.7 PE 68.25% …….. …….. …….. ……..
867 Oct 19 – Oct 24 Sun, Mar, Mer, Sat Oct-24 14.8 EC 100.00% …….. …….. …….. …….. – Jul 20 Sun, Mer, Jup, Ven Jul-11 21.5 PA 49.04% …….. …….. – Feb 05 Sun, Mer, Ven, Sat Jan-27 12 CC 66.41% …….. …….. – Oct 30 Sun, Mer, Jup, Ven Oct-26 13.8 PE 100.00% 100.00% …….. – Jan 19 Sun, Mer, Ven, Sat Jan-08 16.7 EC 100.00% 100.00% …….. – Mar 17 Sun, Mer, Ven, Sat Mar-17 19.3 EC 100.00% 100.00% …….. …….. …….. – May 15 Sun, Mer, Jup, Ven, Sat May-10 18.6 EC 14.91% 19.90% …….. – Aug 19 Sun, Mer, Ven, Sat Aug-13 18.1 EC 28.36% 24.38% …….. – Sep 19 Sun, Mar, Mer, Ven Sep-12 16.9 CC 55.84% 65.41% …….. …….. – Nov 18 Sun, Mar, Mer, Sat Oct-29 11.1 PE 100.00% 99.47% …….. …….. …….. – Nov 29 Sun, Mar, Mer, Sat Nov-17 5 EC 100.00% 100.00% …….. – Nov 28 Sun, Mer, Ven, Sat Nov-19 15.5 EC 55.56% 88.00% ……..
899 Oct 17 - Nov 08 Sun, Mer, Jup, Ven Oct-19 16.5 EC 100.00% 100.00% …….. –‘01Jan 05
Sun, Mer, Jup, Sat Dec-30 17.2 EC 100.00% …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. …….. ……..
917 Jul 10 – Jul 22 Sun, Mer, Ven, Sat Jul-16 17 CCPA 45.81% 58.99% …….. – Aug 25 Sun, Mer, Jup, Ven Aug-20 19.8 CC 67.27% 39.01% …….. – Sep 21 Sun, Mer, Ven, Sat Sep-05 11.1 CC 100.00% 100.00% …….. …….. …….. – Dec 22 Sun, Mar, Mer, Sat Dec-15 17.8 CCPE 44.55% 52.12% …….. – May 17 Sun, Mer, Jup, Ven May-13 17.5 CCPE 32.14% 59.33% …….. …….. …….. …….. …….. – Mar 30 Sun, Mer, Ven, Sat Mar-20 7.1 CCPA 20.00% 25.92% …….. …….. …….. …….. – Oct 20 Sun, Mar, Mer, Jup Oct-15 10 PE 48.45% 28.25% …….. – Nov 21 Sun, Mer, Jup, Ven Nov-19 18.4 PA 48.25% 19.42% …….. ……..
948 Dec 15 –‘49Jan06
Sun, Mar, Mer, Jup Dec-28 13.9 CCPA 49.32% 48.74% 1950 Sep 20 – Sep 30 Sun, Mer, Ven, Sat Sep-25 EC 46.22% 73.92% 1951 Mar 08 – Mar 16 Sun, Mar, Mer, Jup Mar-10 17.2 EC 35.80% 23.68% 1954 Nov 08 – Nov 23 Sun, Mer, Ven, Sat Nov-21 17.4 EC 100.00% 100.00% 1955 Aug 17 – Aug 27 Sun, Mar, Jup, Ven Aug-17 18.3 CCPA 68.93% 95.04% 1957 Sep 30 – Oct 24 Sun, Mar, Mer, Jup Oct-01 14 CCPA 12.42% 11.08% 1958 Oct 18 – Oct 30 Sun, Mer, Jup, Ven Oct-24 19.5 CC 35.77% 61.31% 11.86% 1962 Feb 03 – Feb 17 Sun, Mar, Mer, Jup, Ven, Sat Feb-25 17 EC 80.95% 99.41% 20.74% 1964 Apr 30 - May 03 Sun, Mar, Mer, Jup Apr-30 17.9 EC 100.00% 29.51% 25.73% 1965 Feb 22 – Mar 07 Sun, Mer, Ven, Sat Mar-05 20.3 CCPE 100.00% 100.00% 2.57% 1966 Feb 11 - Mar 14 Sun, Mar, Mer, Sat Feb-25 17.1 CCPA 100.00% 100.00% 4.18% 1970 Oct 25 - Nov 09 Sun, Mer, Jup, Ven Nov-04 12.7 CC 35.89% 76.68% 6.98% 1971 Nov 08 – Nov 29 Sun, Mer, Jup, Ven Nov-11 0.8 CCPA 45.26% 50.53% 17.79% 1973 May 21 - Jun12 Sun, Mer, Ven, Sat May-30 17.4 CCPA 77.78% 100.00% 12.03% 1976 Jul 12 - Aug 04 Sun, Mer, Ven, Sat Jul-25 9.6 EC 100.00% 100.00% 12.75% 1979 Aug 02 – Aug 14 Sun, Mer, Jup, Ven Aug-06 5.6 CCPE 18.05% 22.84% 10.33% 1979 Sep 01 – Sep 17 Sun, Mer, Ven, Sat Sep-13 9.8 EC 8.55% 38.10% 18.10% 980 Aug 30 - Sep 17 Sun, Mer, Jup, Sat Sep-10 6.2 CCPE 47.47% 60.06% 14.68% 1981 Oct 01 – Oct 25 Sun, Mer, Jup, Sat Oct-10 11.5 CC 39.52% 24.68% 20.30% 1985 Nov 22 – Dec 09 Sun, Mer, Jup, Ven Dec-01 15.3 CCPE 100.00% 47.44% 24.89% 1989 May 06 – May 25 Sun, Mer, Jup, Ven May-22 19.4 CC 39.50% 30.97% 9.48% 1994 Feb 07 – Feb 17 Sun, Mer, Ven, Sat Feb-16 17.5 CC 22.67% 51.43% 10.11% 1995 Nov 30 – Dec 06 Sun, Mar, Mer, Jup, Ven Dec-01 6.4 CCPA 23.08% 20.00% 7.49% 1997 Mar 12 – Mar 29 Sun, Mer, Ven, Sat Mar-21 20.1 CCPA 100.00% 100.00% 4.90% 1998 May 23 - Jun 01 Sun, Mar, Mer, Sat May-28 12.1 CC 29.11% 86.44% 25.4% 2000 Apr 28 – May 16 Sun, Mar, Mer, Jup, Sat May-05 20.1 EC 49.40% 84.34% 23.8 % able 2. Calculations of normalized sunspot activity decreases during multiple planetary conjunction periods of the years 1850-2000 AD Conjunction date Duration of SSN decrease 𝑹 𝒎𝒂𝒙 𝑹 𝒎𝒊𝒏 𝜹 𝑹 = 𝑹 𝒎𝒂𝒙 − 𝑹 𝒎𝒊𝒏 𝑹 𝒎𝒂𝒙 + 𝑹 𝒎𝒊𝒏 – Sep 18 3 86 52 24.64% 1851 Oct 1 - Nov 08 8 104 36 48.57% 1852 Nov 05 – Nov 19 4 105 11 81.03% 1856 Jun 15 – Jun 30 16 15 0 100.00% 1857 Apr 11 – Apr 21 6 32 0 100.00% 1858 Apr 11 – May 11 8 74 8 80.49% 1859 Jun 13 – Jul 11 7 122 47 44.38% 1860 Jun30 - Jul 20 14 220 52 61.76% 1861 Aug 29 – Sep 18 15 139 41 54.44% 1862 Aug 25 - Sep 18 25 96 16 71.43% 1863 Aug 30 - Sep 09 11 34 0 100.00% 1863 sep 29 – Oct 16 5 75 16 64.84% 1864 Sep 05 – Sep 21 3 53 10 68.25% 1865 Oct 18 - Nov 06 20 42 0 100.00% 1867 Oct 19 – Oct 24 6 18 0 100.00% 1869 Apr 20 - May 01 0 66 16 60.98% 1872 Jul 10 – Jul 20 6 196 67 49.04% 1874 Jan 16 – Feb 05 7 109 22 66.41% 1875 Oct 09 – Oct 30 17 37 0 100.00% 1876 Jan 04 – Jan 19 15 8 0 100.00% 1877 Mar 15 – Mar 17 8 14 0 100.00% 1880 Mar 17-Mar 30 8 49 0 100.00% 1881 Apr 29 - May 05 5 65 4 88.41% 1882 Apr 19 – May 15 7 158 117 14.91% 1888 Aug 02 – Aug 19 10 43 24 28.36% 1891 Sep 04 – Sep 19 6 120 34 55.84% 1893 Sep 30 5 100 47 36.05% 1895 Oct 25 – Nov 18 3 119 0 100.00% 1896 Jul 29 - Aug 15 18 33 0 100.00% 1897 Sep 07 - Sep 15 7 83 11 76.60% 1897 Nov 05 – Nov 29 7 16 0 100.00% 1898 Nov 15 – Nov 28 14 35 10 55.56% 1899 Oct 17 - Nov 08 7 15 0 100.00% 1900 Dec27 –‘01Jan 05
10 14 0 100.00% 1902 Jan 01 - Jan 09 4 25 0 100.00% 1903 Jan 01 - 18 10 16 0 100.00% 1903 Jan 20 - Feb 02 3 13 0 100.00% 1905 Apr 11 - May 05 7 59 22 45.68% 906 Feb 10 - 28 9 39 11 56.00% 1906 May 03 -13 5 52 32 23.81% 1906 Jun 02-17 6 108 15 75.61% 1907 Jul 25 - Aug 06 5 67 39 26.42% 1908 Aug 07 - 30 7 136 32 61.90% 1910 Oct 10 - Nov 09 13 43 0 100.00% 1912 May 27 - Jun4 2 13 0 100.00% 1914 Jan 07 - 30 20 17 0 100.00% 1915 Mar 04 - 30 5 77 7 83.33% 1916 Jul 09 - Jul 16 8 43 7 72.00% 1917 Apr 13 - May 16 6 160 57 47.47% 1917 Jul 10 – Jul 22 5 148 55 45.81% 1920 Jul 20 – Aug 25 6 46 9 67.27% 1921 Sep 01 – Sep 21 8 82 0 100.00% 1922 Sep 29 - Oct 24 15 10 0 100.00% 1923 Nov 17 - Nov 23 7 9 0 100.00% 1929 Dec 01 – Dec 22 22 146 56 44.55% 1930 May 10 – May 17 5 37 19 32.14% 1933 Feb 11 67 0 100.00% 1934 Jan 30 - Feb 12 20 12 0 100.00% 1934Oct 30 - Nov 16 6 16 0 100.00% 1935 Jan 22 - Feb 17 7 32 9 56.10% 1938 Mar 06 – Mar 30 2 78 52 20.00% 1941 Apr 29 - May 18 5 45 12 57.89% 1944 Jun 16 - Jul 09 5 8 0 100.00% 1944 Aug 21 -Aug 31 4 34 0 100.00% 1946 Oct 09 – Oct 20 3 144 50 48.45% 1946 Nov 17 – Nov 21 2 169 59 48.25% 1947 Oct28 - Nov 05 8 233 74 51.79% 1948 Dec 15 –‘49Jan06
10 221 75 49.32% 1950 Sep 20 – Sep 30 11 87 32 46.22% 1951 Mar 08 – Mar 16 8 55 26 35.80% 1954 Nov 08 – Nov 23 14 41 0 100.00% 1954 Nov 18 – Nov 23 6 24 8 50.00% 1955 Aug 17 – Aug 27 7 87 16 68.93% 1957 Sep 30 – Oct 24 2 276 215 12.42% 1958 Oct 18 – Oct 30 6 241 114 35.77% 1962 Feb 03 – Feb 17 15 76 8 80.95% 1964 Apr 30 - May 03 4 23 0 100.00% 1965 Feb 22 – Mar 07 4 26 0 100.00% 1966 Feb 11 - Mar 14 9 17 0 100.00% 1970 Oct 25 - Nov 09 7 142 67 35.89% 1971 Nov 08 – Nov 29 16 69 26 45.26% 1973 May 21 - Jun12 7 56 7 77.78% 976 Jul 12 - Aug 04 22 10 0 100.00% 1979 Aug 02 – Aug 14 13 121 84 18.05% 1979 Sep 01 – Sep 17 0 165 139 8.55% 1980 Aug 30 - Sep 17 3 233 83 47.47% 1981 Oct 01 – Oct 25 4 233 101 39.52% 1985 Nov 22 – Dec 09 7 43 0 100.00% 1989 May 06 – May 25 2 196 85 39.50% 1994 Feb 07 – Feb 17 2 46 29 22.67% 1995 Nov 30 – Dec 06 2 16 10 23.08% 1997 Mar 12 – Mar 29 5 19 0 100.00% 1998 May 23 - Jun 01 3 51 28 29.11% 2000 Apr 28 – May 16 13 124 42 49.40%
Table 3: Frequency of occurrences of different categories of sunspot activity ( SSA) decreases during Planetary conjunction periods of 1850-2000 AD Category of SSA decrease during MPC No. of occurrences during 1850-2000 AD
CC 13 PE 11 CCPA 21 NE 15 EC 29 PA 10 CCPE 11
Table 4 Details of ExtremeSpace weather events between 1850-2000 AD. Association with MPC periods if any is indicated .
Sl. No. Date of SW event Type Index of activity Value Association with MPC period if any able 5 List of lunar missions associated with multiple planetary conjunctions during 1957-2000 AD Spacecraft Launch date Mission Mission duration Country Status Conjunction period
E-1,No.3 4 Dec 1958 Impactor Failed to orbit Soviet Union Failure 1958 Nov 23 – Dec 17 Pioneer 3 6 Dec 1958 Flyby Failed to orbit USA Failure 1958 Nov 23 – Dec 17 Ranger 8 17 Feb 1965 Impactor 65 hours USA Successful 1965 Feb 22- Mar 7 AS 201 26 Feb 1965 Space orbitor test flight USA Successful 1965 Feb 22- Mar 7 Luna 9 31 Jan 1966 Lunar lander 6 days Soviet Union Successful 1966 Feb 11- Mar 14 KOSMOS 111 1 Mar 1966 Orbitor Failed to orbit Soviet Union Failure 1966 Feb 11 – Mar 14 Zond 8 20 Oct 1970 Flyby Soviet Union Successful 1970 Oct 25 – Nov 9 Explorer 49 10 Jun 1973 Orbitor 2 years USA Successful 1973 May 21 – Jun 12 Luna 24 9 Aug 1979 Lunar sample return 13 days Soviet Union Successful 1979 Aug 2 -14 Clementine 25 Jan 1994 Orbitor 115 days USA Successful 1994 Feb 7 -27
Table 6 List of human space flight missions associated with multiple planetary conjunctions for the period 1961 – Mercury- Atlas(6) 1962 Feb 20 1962 Feb 20 1962 Feb 03- Feb 17 J. H.Glenn Gemini 4 1965 Jun 03 1965 Jun 07 1965 Jun 03- Jun 07 J. A. Mcdivitt E. H. White Gemini 8 1966 Mar 16 1966 Mar 17 1966 Feb 11- Mar 14 N. A. Armstrong D. R. Scott kylab 2 1973 May 25 1973 Jun 22 1973 May 21-Jun12 C. P. Conrad P. J. Weitz J. P. Kerain Soyuz 38 1980 Sep 18 1980 Sep 26 1980 Aug 30- Sep 17 Y. Romanenko A. T. Mendez STS-5
Columbia
Atlantis
B. D O’Connor
M. L. Cleave S. C. Spring J. L. Ross R.Neri Vela C. D. Walker STS-51-L
Challenger
Atlantis – May 08 D. A. Walker R. J. Grabe N. E. Thagard M. L. Cleave M. C. Lee STS-60
Discovery
Atlantis
Table 7: Triple conjunctions during 2001-2020 and associated solar-terrestrial conditions Date of closest Triple conjunction Planets in Conjunction Solar/Sunspot activity decrease if any Space weather events associated if any Space missions associated if any (Human)
Ven,Uran,Mar Nil 2009 Oct 9