RFO

What's Up in the Night Sky

Here's a month-by-month listing of astronomical predictions for the year, compiled by
Jack Welch, RFO astronomy instructor.

 

Abbreviations

Astr Twi/AT -Astronomical Twilight
Cal - Callisto
Civ Twi/CT - Civil Twilight
Cr - Crescent
Disap - Disappear
Dbl Tr - Double Tansit
E - End/Exit
Ec/Ecl - Eclipse
EcD - Eclipse disappearance
EcR - Eclipse reappearance
Eur - Europa
Ex - Exit
Gan - Ganymede
Gr El - Greatest Elongation
Jup - Jupiter
Lun - Lunar
Max - Maximum
Mer - Mercury
Min - Minimum
Mn - Moon
Naut Twi/NT - Nautical Twilight
Nr - Near
Occ - Occultation
OcD - Occultation disappearance
OcR - Occultation reapparance
Opp - Opposition
Pen - Penumbral
Reap - Reappear
Qtr - Quarter
Sat - Saturn /Satellite
Sh - Shadow
S/St - Start
Stat - Stationary
Tot - Total
Tr - Transit
V Nr - Very Near
Ven - Venus
Zod Lt - Zodiacal Light

 

Observing

Upcoming Observing Highlights

February 2017
  • Wednesday, 2/1/2017 - Gan Sh Tr - Time: 24:00
    • In progress when Jupiter rises, Ganymede's shadow ends its transit of the north polar region at 0125. Note that Jupiter's altitude (calculated for RFO) is 9° at midnight.
  • Friday, 2/3/2017 - 1st Qtr - Time: 20:30
    • -
  • Sunday, 2/5/2017 - Mn vnr Aldebaran - Time: 19:00
    • -
  • Sunday, 2/5/2017 - Occ of ZC741 - Time: 22:30
    • At about 2246 the mag 5.5 star ZC741 will disappear behind the moon's dark limb 86° from the north cusp. ZC741 is an extremely close equal double, which may be detectable for those with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Monday, 2/6/2017 - Io EcD - Time: 01:30
    • At 0131 Io disappears into Jupiter's shadow 0.5 Jupiter disk width west of Jupiter.
  • Monday, 2/6/2017 - Jup stat - Time: 11:00
    • Jupiter begins retrograde motion near the bright star Spica in Virgo, which serves as a convenient reference for tracking Jupiter's sky motion.
  • Monday, 2/6/2017 - Io Sh/Sat Tr - Time: 23:30
    • In progress when Jupiter rises, Io's shadow transits Jupiter, ending at 0105 followed by Io itself from 2359 to 0209. Note that Jupiter's altitude (calculated for RFO) is 12° at 2359.
  • Thursday, 2/9/2017 - Gan Sh Tr - Time: 02:30
    • Ganymede's shadow transits Jupiter's north polar region from 0248 to 0522.
  • Friday, 2/10/2017 - Eur EcD - Time: 01:00
    • Europa disappears into Jupiter's shadow 0.7 Jupiter disk diameter west of Jupiter at 0102.
  • Friday, 2/10/2017 - "Snow" Moon - Time: 16:30
    • -
  • Saturday, 2/11/2017 - Mn Vnr Regulus - Time: 04:00
    • The moon is VERY near the very bright blue star Regulus in Leo, growing closer as dawn approaches. Use binoculars to appreciate this colorful sight.
  • Saturday, 2/11/2017 - Algol min - Time: 05:30
    • Algol eclipse minimum is at 0544.
  • Sunday, 2/12/2017 - Gan OcR - Time: 23:00
    • At 2325 Ganymede reappears from behind Jupiter's south-southeast limb.
  • Monday, 2/13/2017 - Zod Light in W thru 2/26 - Time: 19:30
    • Look for the zodiacal light in the west after twilight from a dark site without western light pollution. Best times to look are from about 1930 to 2000. Note that glare from Venus interferes this year.
  • Tuesday, 2/14/2017 - Io Sh/Sat Tr - Time: 00:30
    • Io's shadow transits Jupiter from 0046 to 0258 followed by Io itself from 0148 to 0358.
  • Tuesday, 2/14/2017 - Algol min - Time: 02:30
    • Algol eclipse minimum is at 0233.
  • Tuesday, 2/14/2017 - Mn nr Jup - Time: 24:00
    • -
  • Wednesday, 2/15/2017 - Io OcR - Time: 01:00
    • At 0106 Io reappears from behind Jupiter's east limb.
  • Thursday, 2/16/2017 - Algol min - Time: 23:30
    • Algol eclipse minimum is at 2323.
  • Thursday, 2/16/2017 - Ven brightest - Time: 23:00
    • Venus is at its brightest now, at mag -4.8.
  • Saturday, 2/18/2017 - Last Qtr - Time: 11:30
    • -
  • Saturday, 2/18/2017 - Eur Sh/Sat Tr - Time: 23:00
    • In progress when Jupiter rises, Europa's shadow transits Jupiter, ending at 0015 followed by Europa itself from 2345 to 0206. Note that Jupiter's altitude (calculated for RFO) is 10° at 2300.
  • Sunday, 2/19/2017 - Algol min - Time: 20:00
    • Algol eclipse minimum is at 2012.
  • Sunday, 2/19/2017 - Gan EcR/OcD - Time: 23:00
    • At 2323 Ganymede reappears from Jupiter's shadow slighly west of Jupiter's southwest limb. Then Ganymede disappears behind Jupiter at 0058.
  • Monday, 2/20/2017 - CrMn nr Sat - Time: 05:00
    • -
  • Tuesday, 2/21/2017 - Io Sh/Sat Tr - Time: 02:30
    • Io's shadow transits Jupiter from 0239 to 0451 followed by Io itself from 0336 to 0546.
  • Tuesday, 2/21/2017 - CrMn nr Sat - Time: 05:00
    • -
  • Tuesday, 2/21/2017 - Io EcD/OcR - Time: 23:30
    • At 2346 Io disappears into Jupiter's shadow 0.4 Jupiter diameter west of Jupiter. Then Io reappears from behind Jupiter's east limb at 0254.
  • Saturday, 2/25/2017 - Eur Sh/Sat Tr - Time: 24:00
    • Europa's shadow transits Jupiter from 0019 to 0249 followed by Europa itself from 0208 to 0428.
  • Sunday, 2/26/2017 - New Moon - Time: 07:00
    • -
  • Monday, 2/27/2017 - Gan Ec & OcD - Time: 00:30
    • At 0047, Ganymede disappears into Jupiter's shadow about 0.9 Jupiter disk width west of Jupiter, then reappears from the shadow at 0320 near the southwest polar limb. Ganymede disappears behind Jupiter at 0429.
  • Monday, 2/27/2017 - 2.8% CrMn - Time: 18:30
    • A very thin 2.8% crescent moon is visible 40 minutes after sunset (1842 calculated for the RFO site) 19° high 21° south of due west.
  • Monday, 2/27/2017 - Eur OcR - Time: 23:30
    • At 2333, Europa reappears from behind Jupiter's southeast limb.

March 2017
  • Wednesday, 3/1/2017 - Io EcD/OcR - Time: 01:30
    • Io disappears into Jupiter's shadow at 0139 0.3 Jupiter diameter width west of Jupiter, then reappears from behind Jupiter's east limb at 0440.
  • Wednesday, 3/1/2017 - CrMn nr Mar - Time: 19:30
    • -
  • Wednesday, 3/1/2017 - Io Sh/Sat Tr - Time: 23:00
    • Io's shadow transits Jupiter from 2300 to 0113 followed by Io itself from 2349 to 0159.
  • Thursday, 3/2/2017 - Io OcR - Time: 23:00
    • Io reappears from behind Jupiter's east limb at 2307.
  • Saturday, 3/4/2017 - Occ of theta-1 & theta-2 Tau - Time: 14:30
    • Note: These daylight occultations require larger aperture scopes for viewing. At about 1435 the mag 3.8 star theta-1 Tauri will disappear behind the moon's dark limb 79° from the north cusp. Then, at about 1436 the mag 3.4 star theta-2 Tauri will disappear behind the moon's dark limb 81° from the south cusp. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Saturday, 3/4/2017 - Occ of Aldebaran - Time: 19:00
    • At about 1902 the mag 0.9 red-orange star Aldebaran (alpha Tauri) will disappear behind the moon's dark limb 65° from the north cusp. Then, at about 2015 Aldebaran will reappear from behind the bright limb at axis angle 292°, or 68° from the north cusp. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Sunday, 3/5/2017 - Eur Sh/Sat Tr - Time: 02:30
    • Europa's shadow transits Jupiter from 0254 to 0524, followed by Europa itself starting at 0428 (and still in progress at sunrise).
  • Sunday, 3/5/2017 - 1st Qtr - Time: 03:30
    • -
  • Monday, 3/6/2017 - Algol min - Time: 04:30
    • Algol eclipse minimum is at 0418.
  • Monday, 3/6/2017 - Eur EcD/OcR - Time: 22:00
    • Europa disappears into Jupiter's shadow 0.4 Jupiter diameter west of Jupiter at 2202, then reappears from behind Jupiter's east limb at 0152.
  • Tuesday, 3/7/2017 - Occ of 74 Gem - Time: 21:30
    • At about 2158 the mag 5.0 star 74 Geminorum will disappear behind the moon's dark limb 89° from the south cusp. 74 Gem is an extremely close equal double, which may be detectable for those with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Thursday, 3/9/2017 - Io Sh/Sat Tr - Time: 00:30
    • Io's shadow transits Jupiter from 0054 to 0306 followed by Io itself from 0134 to 0345.
  • Thursday, 3/9/2017 - Algol min - Time: 01:00
    • Algol eclipse minimum is at 0108.
  • Thursday, 3/9/2017 - Gan Tr & Io EcD/OcR - Time: 21:30
    • Ganymede transits Jupiter's north polar region from 2130 (Jupiter altitude 9° calculated for RFO site) to 2329. Meanwhile, Io disappears into Jupiter's shadow 0.25 Jupiter disk width west of Jupiter at 2201 and reappears from behind Jupiter's east limb at 0052.
  • Friday, 3/10/2017 - Mn vnr Regulus - Time: 19:30
    • Use binoculars to view the moon very near the very bright blue star Regulus in Leo.
  • Saturday, 3/11/2017 - Algol min - Time: 22:00
    • Algol eclipse minimum is at 2157.
  • Sunday, 3/12/2017 - DST begins - Time: 02:00
    • -
  • Sunday, 3/12/2017 - "Worm" Moon - Time: 08:00
    • -
  • Tuesday, 3/14/2017 - Eur EcD/OcR - Time: 01:30
    • At 0136 Europa disappears into Jupiter's shadow 0.33 Jupiter diameter west of Jupiter. Then Europa reappears from behind Jupiter's east limb at 0509.
  • Tuesday, 3/14/2017 - Mn vnr Jup - Time: 06:00
    • -
  • Tuesday, 3/14/2017 - Algol min - Time: 20:00
    • Algol eclipse minimum is at 1946.
  • Wednesday, 3/15/2017 - Zod Light in W thru 3/28 - Time: 21:00
    • Look for the zodiacal light in the west after twilight from a dark site without western light pollution. Best times to look are from about 2100 to 2130.
  • Wednesday, 3/15/2017 - Eur Sh/Sat Tr - Time: 22:00
    • In progress when Jupiter rises, Europa's shadow ends transit at 2217 (at which time Jupiter's altitude is 11° calculated for the RFO site), and Europa itself ends transit at 2316.
  • Thursday, 3/16/2017 - Io Sh/Sat Tr - Time: 03:30
    • Io's shadow transits Jupiter from 0347 to 0559 followed by Io itself from 0419 to 0629.
  • Thursday, 3/16/2017 - Gan Sh/Sat Tr & Io EcD/OcR - Time: 23:30
    • Ganymede's shadow transits Jupiter's north polar region from 2336 to 0205, followed by Ganymede itself from 0152 to 0351. Meanwhile, Io disappears into Jupiter's shadow at 0055 0.2 Jupiter disk width west of Jupiter, then reappears from behind Jupiter's east limb at 0337.
  • Friday, 3/17/2017 - Io Sh/Sat Tr - Time: 22:00
    • Io's shadow transits Jupiter from 2215 to 0028 followed by Io itself from 2245 to 0055.
  • Saturday, 3/18/2017 - Io OcR - Time: 22:00
    • Io reappears from behind Jupiter's east limb at 2203.
  • Monday, 3/20/2017 - Vernal Equinox - Time: 03:30
    • The vernal equinox occurs at 3:28am.
  • Monday, 3/20/2017 - Mn vnr Sat - Time: 04:00
    • -
  • Monday, 3/20/2017 - Last Qtr - Time: 09:00
    • -
  • Tuesday, 3/21/2017 - Mer in W thru 4/10 - Time: 20:00
    • Mercury provides its best evening apparition of 2017, reaching a maximum altitude of 9° 45 minutes after sunset on 3/31.
  • Wednesday, 3/22/2017 - Eur Sh/Sat Tr - Time: 22:00
    • Europa's shadow transits Jupiter from 2223 to 0052, followed by Europa itself from 2312 to 0133.
  • Friday, 3/24/2017 - Io EcD/OcR & Gan Sh/Sat Tr - Time: 02:30
    • At 0249 Io disappears into Jupiter's shadow 0.1 Jupiter disk width west of Jupiter. Ganymede's shadow transits the north polar region from 0334 to 0603. Ganymede's transit begins at 0510 and is on-going at daybreak. Io reappears from behind Jupiter's east limb at 0522.
  • Friday, 3/24/2017 - Io Sh/Sat Tr - Time: 24:00
    • Io's shadow transits Jupiter from 0009 to 0221 followed by Io itself from 0029 to 0239.
  • Saturday, 3/25/2017 - Ven IC - Time: 03:00
    • This inferior conjunction of Venus is unusual in that Venus will be 8° north of the sun. This results in Venus technically (if challengingly) being viewable in both the evening and morning skies from about 3/22 to 3/24.
  • Saturday, 3/25/2017 - Io EcD/OcR - Time: 21:00
    • Io disappears into Jupiter's shadow 0.1 Jupiter diameter west of Jupiter at 2117. Note that Jupiter's altitude at this time will be 9° (calculated for the RFO site). Then Io reappears from behind Jupiter's east limb at 2348.
  • Monday, 3/27/2017 - New Moon - Time: 20:00
    • -
  • Tuesday, 3/28/2017 - 1.5% CrMn - Time: 20:00
    • An ultra-thin 1.5% crescent moon will be 5° high 2° north of due west 30 minutes after sunset (at 2000 calcuated for the RFO site). Use binoculars!
  • Thursday, 3/30/2017 - Eur Sh/Sat Tr - Time: 00:30
    • Europa's shadow transits Jupiter from 0058 to 0327, followed by Europa itself from 0127 to 0348.
  • Friday, 3/31/2017 - Occ of Hyadum-I - Time: 20:00
    • At about 2027 the mag 3.7 star Hyadum-I (gamma Tauri) will disappear behind the moon's dark limb 42° from the south cusp. Then, at about 2111 it will reappear from behind the bright limb at axis angle 224° (40° from the south cusp). The reappearance event requires larger aperture scopes. Hyadum-I is a very close double so a double event may be detectable with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Friday, 3/31/2017 - Eur OcR - Time: 22:30
    • Europa reappears from behind Jupiter's southeast limb at 2246.
  • Friday, 3/31/2017 - Occ of 70 Tau - Time: 22:30
    • At about 2256 the mag 6.6 star 70 Tauri will disappear behind the moon's dark limb 85° from the south cusp. This event requires larger aperture scopes. 74 Gem is an extremely close equal double, which may be detectable for those with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)

April 2017
  • Saturday, 4/1/2017 - Io Sh/Sat Tr - Time: 02:00
    • Io's shadow transits Jupiter from 0203 to 0415, followed quite closely by Io itself from 0213 to 0423.
  • Saturday, 4/1/2017 - Mer in W thru 4/10 - Time: 20:00
    • Mercury provides its best evening apparition of 2017, reaching a maximum altitude of 9° 45 minutes after sunset on 3/31.
  • Saturday, 4/1/2017 - Occ of 115 Tau - Time: 23:30
    • At about 2337 the mag 5.4 star 115 Tauri will disappear behind the moon's dark limb 61° from the north cusp. 115 Tau is an extremely close equal double, which may be detectable for those with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Saturday, 4/1/2017 - Io EcD/OcR - Time: 23:00
    • Io disappears into Jupiter's shadow 0.1 Jupiter disk width west of Jupiter at 2311. Io reappears from behind Jupiter's east limb at 0132.
  • Sunday, 4/2/2017 - Io Sh/Sat Tr - Time: 20:30
    • Io's shadow transits Jupiter's disk from 2031 (during nautical twilight with Jupiter's altitude 7° at start) to 2243, followed very closely by Io itself from 2039 to 2249.
  • Monday, 4/3/2017 - 1st Qtr - Time: 11:30
    • -
  • Monday, 4/3/2017 - Gan EcR/OcD - Time: 21:30
    • Ganymede disappears into Jupiter's shadow 0.1 Jupiter disk diameter from the southwest polar limb at 2137. Ganymede reappears from behind the southeast polar limb at 0014.
  • Wednesday, 4/5/2017 - Sat stat - Time: 22:00
    • Saturn begins retrograde motion.
  • Thursday, 4/6/2017 - Eur Sh/Sat Tr - Time: 03:30
    • Occurring soon before opposition, Europa and its shadow will be extremely close and may even overlap during this event. The shadow transits Jupiter from 0335 to 0603, followed by Europa from 0342 to 0604 (during nautical twilight).
  • Thursday, 4/6/2017 - Mn Vnr Regulus - Time: 22:00
    • -
  • Friday, 4/7/2017 - Jup opp - Time: 15:00
    • Jupiter is at opposition in Virgo, at mag -2.5 and a disk diameter of 44.2".
  • Friday, 4/7/2017 - Eur Ec - Time: 22:30
    • With Jupiter at opposition, its shadow and limb are virtually coincident. While technically an eclipse, the event appears as an occultation. Europa disappears behind Jupiter's southwest limb at 2236 and reappears at the southeast limb at 0104.
  • Saturday, 4/8/2017 - Io Sat/Sh Tr - Time: 03:30
    • Coming very shortly after opposition, Io will overlap its shadow during this event. Io transits from 0356.4 to 0607, followed extremely closely by its shadow from 0356.5 to 0609 (ending in nautical twilight with Jupiter's altitude 9°).
  • Sunday, 4/9/2017 - Io OcD/EcR - Time: 01:00
    • Io disappears behind Jupiter's west limb at 0104 and reappears from Jupiter's shadow extremely close to Jupiter's east limb at 0319.
  • Sunday, 4/9/2017 - Io Sat/Sh Tr - Time: 22:00
    • Coming soon after opposition, Io will be followed extremely closely by its shadow, with slight overlap possible. Io transits Jupiter from 2222 to 0033, and its shadow from 2225 to 0037.
  • Monday, 4/10/2017 - Occ of Porrima - Time: 00:30
    • Note: This event requires larger aperture scopes. At about 0055 the mag 2.8 star Porrima (gamma Virginis) disappears behind the moon's dark limb 13° from the north cusp. Then, at about 0125 it reappears from behind the bright limb at axis angle 344° (or 28° from the north cusp). Porrima is a close equal double so a double event may be detectable with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Monday, 4/10/2017 - Mn vnr Jup - Time: 20:30
    • -
  • Monday, 4/10/2017 - Io EcR - Time: 21:30
    • Io reappears from Jupiter's shadow very close to Jupiter's east limb.
  • Monday, 4/10/2017 - "Pink" Moon - Time: 23:00
    • -
  • Tuesday, 4/11/2017 - Gan OcD/EcR - Time: 01:00
    • Ganymede disappears behind Jupiter's southwest polar limb at 0127. Ganymede reappears from Jupiter's shadow 0.1 Jupiter disk diameter from Jupiter's southeast polar limb at 0404.
  • Saturday, 4/15/2017 - Eur OcD/EcR - Time: 00:30
    • Europa will disappear behind Jupiter's southwest limb at 0051 then reappear from Jupiter's shadow 0.1 Jupiter disk diameter from the southeast limb at 0338.
  • Saturday, 4/15/2017 - Occ of ZC2399 - Time: 02:00
    • At about 0219 the mag 4.9 star ZC2399 reappears from behind the moon's dark limb at axis angle 288° (or 68° from the north cusp). (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Sunday, 4/16/2017 - Io OcD/EcR - Time: 02:30
    • Io disappears behind Jupiter's west limb at 0248 and reappears from Jupiter's shadow 0.1 Jupiter disk diameter from Jupiter's east limb at 0513.
  • Sunday, 4/16/2017 - Mn nr Sat - Time: 05:00
    • -
  • Sunday, 4/16/2017 - Eur Sat/Sh Tr - Time: 20:30
    • Both transits are in progress at sunset. Europa's transit of Jupiter ends at 2128 and its shadow transit ends at 2157.
  • Sunday, 4/16/2017 - Io Sat/Sh Tr - Time: 24:00
    • Io transits Jupiter from 0006 to 0217 followed by its shadow from 0019 to 0231.
  • Monday, 4/17/2017 - Io OcD/EcR - Time: 21:00
    • Io disappears behind Jupiter's west limb at 2114 and reappears from Jupiter's shadow 0.1 Jupiter disk diameter from Jupiter's east limb at 2342.
  • Wednesday, 4/19/2017 - Last Qtr - Time: 03:00
    • -
  • Friday, 4/21/2017 - Gan Sh Tr - Time: 21:00
    • In progress at sunset, Ganymede's shadow ends its transit of Jupiter's north polar region at 2151.
  • Saturday, 4/22/2017 - Eur OcD - Time: 03:00
    • Europa disappears behind Jupiter's southwest limb at 0306.
  • Saturday, 4/22/2017 - Lyrids Peak - Time: 05:00
    • The Lyrid Meteor Shower is expected to peak sometime this night, probably within a few hours of 5am. Meteor viewing is favorable from about 10pm until crescent moonrise at 0418. About 18 meteors per hour may occur at peak, but activity can vary greatly.
  • Sunday, 4/23/2017 - CrMn nr Ven - Time: 05:30
    • -
  • Sunday, 4/23/2017 - Eur Sat/Sh Tr - Time: 21:00
    • Europa transits Jupiter's disk from 2120 to 2345 followed by its shadow from 2206 to 0033.
  • Monday, 4/24/2017 - Io Sat/Sh Tr - Time: 01:30
    • Io transits Jupiter from 0150 to 0401 followed by its shadow from 0213 to 0425.
  • Monday, 4/24/2017 - Io OcD/EcR - Time: 22:30
    • Io disappears behind Jupiter's west limb at 2259 and reappears from Jupiter's shadow 0.15 Jupiter disk diameter from Jupiter's east limb at 0136.
  • Tuesday, 4/25/2017 - Io Sat/Sh Tr - Time: 20:30
    • Io's transit of Jupiter is in progress as Jupiter becomes visible in twilight and it ends at 2227. Io's shadow transits from 2041 to 2253.
  • Wednesday, 4/26/2017 - New Moon - Time: 05:00
    • -
  • Thursday, 4/27/2017 - Lrg Tides thru 4/29 - Time: 00:00
    • Large tides caused by the new moon 28 hours before perigee.
  • Thursday, 4/27/2017 - 4.3% CrMn - Time: 20:30
    • -
  • Friday, 4/28/2017 - Gan Sat/Sh Tr - Time: 21:30
    • Ganymende transits Jupiter's north polar region from 2130 to 2343, followed by its shadow from 2325 to 0149.
  • Saturday, 4/29/2017 - Ven brightest - Time: 21:00
    • Venus reaches magnitude -4.7.
  • Sunday, 4/30/2017 - Eur Sat/Sh Tr - Time: 23:30
    • Europa transits Jupiter from 2337 to 0202 followed by its shadow from 0042 to 0310.
  • Monday, 4/31/2017 - Eur Sat/Sh Tr - Time: 23:30
    • Europa transits Jupiter from 2337 to 0202 followed by its shadow from 0042 to 0310.

May 2017
  • Tuesday, 5/2/2017 - Io OcD/EcR - Time: 00:30
    • Io disappears behind Jupiter's west limb at 0044 and reappears from Jupiter's shadow 0.2 Jupiter disk diameter from Jupiter's east limb at 0331.
  • Tuesday, 5/2/2017 - 1st Qtr - Time: 20:00
    • -
  • Tuesday, 5/2/2017 - Io Sat/Sh Tr & Eur EcR - Time: 22:00
    • Io transits Jupiter from 2201 to 0012 followed by its shadow from 2236 to 0047. Right as Io's transit starts, Europa will emerge from Jupiter's shadow at 2202 about 0.4 Jupiter diameter east of Jupiter's SE limb.
  • Wednesday, 5/3/2017 - Io EcR - Time: 21:30
    • At 2159 Io emerges from Jupiter's shadow 0.2 Jupiter diameter east of Jupiter.
  • Thursday, 5/4/2017 - Mn vnr Regulus - Time: 01:00
    • Use binoculars to view the moon very near the bright blue star Regulus.
  • Saturday, 5/6/2017 - Gan Sat/Sh Tr - Time: 00:30
    • Ganymede transits Jupiter's north polar region from 0051 to 0307 followed by its shadow starting at 0325. Jupiter will set with the shadow transit in progress.
  • Sunday, 5/7/2017 - Mn vnr Jup - Time: 21:00
    • -
  • Monday, 5/8/2017 - Eur Sat/Sh Tr - Time: 01:30
    • Europa transits Jupiter from 0156 to 0422 (by which time Jupiter's altitude will be on 5° calculated for the RFO site). Europa's shadow transit begins at 0320. Jupiter sets with the shadow transit in progress.
  • Tuesday, 5/9/2017 - Io OcD - Time: 02:30
    • Io will disappear behind Jupiter at 0230.
  • Tuesday, 5/9/2017 - Eur OcD - Time: 20:30
    • Europa will disappear behind Jupiter at 2045, at which time Callisto, Ganymede and Io (listed from west to east) will form a striking triangle arrangement just east of Jupiter.
  • Tuesday, 5/9/2017 - Io Sat/Sh Tr & Eur EcR - Time: 23:30
    • Io will transit Jupiter from 2347 to 0158, followed by its shadow from 0030 to 0241. Meanwhile, Europa will reappear from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter. Even more, Callisto will slowly pass just above Jupiter's north polar region during these events!
  • Wednesday, 5/10/2017 - "Flower" Moon - Time: 14:30
    • -
  • Wednesday, 5/10/2017 - Io OcD/EcR - Time: 20:30
    • At 2057 (during nautical twilight) Io will disappear behind Jupiter. Then, at 2354 it reappears from Jupiter's shadow 0.3 Jupiter diameter east of Jupiter.
  • Tuesday, 5/16/2017 - Gan Ec & Eur OcD - Time: 21:30
    • At 2132 Ganymede will disappear into Jupiter's shadow 0.2 Jupiter diameter east of Jupiter's SE limb, then reappear from the shadow 0.9 diameter east at 2354. Meanwhile, Europa disappears behind Jupiter at 2302.
  • Wednesday, 5/17/2017 - Io Sat/Sh Tr & Eur EcR - Time: 01:30
    • Io will transit Jupiter from 0134 to 0345 (by which time Jupiter's altitude is 5° calculated for the RFO site), followed by its shadow starting at 0224. Meanwhile Europa will emerge from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter at 0310. Jupiter sets with Io's shadow in transit.
  • Wednesday, 5/17/2017 - Io OcD/EcR - Time: 22:30
    • Io disappears behind Jupiter at 2244 and reappears from Jupiter's shadow 0.3 Jupiter diameter east of Jupiter at 0149.
  • Thursday, 5/18/2017 - Last Qtr - Time: 17:30
    • -
  • Thursday, 5/18/2017 - Dbl Sh Tr of Jup - Time: 20:30
    • Europa's shadow and Io are already transiting Jupiter at sunset. Then the sequence is:
      2053 Io's Sh Tr begins (Dbl Sh Tr begins)
      2142 Europa's Sh Tr ends (Dbl Sh Tr ends)
      2212 Io's Tr ends
      2304 Io's Sh Tr ends
  • Monday, 5/22/2017 - CrMn vnr Ven - Time: 05:00
    • -
  • Tuesday, 5/23/2017 - Gan Oc/Ec & Eur OcD - Time: 21:30
    • Ganymede disappears behind the west side of Jupiter's south polar at 2135 and reappears from behind the east side at 0000. At 0124 Europa disappears behind Jupiter. Then at 0131 Ganymede disappears into Jupiter's shadow 0.3 Jupiter diameter east of Jupiter's south polar region.
  • Thursday, 5/25/2017 - VLrg Tides thru 5/27 - Time: 00:00
    • The new moon occurs just 5hr before perigee causing very large tides.
  • Thursday, 5/25/2017 - Io OcD - Time: 00:30
    • Io disappears behind Jupiter at 0032.
  • Thursday, 5/25/2017 - New Moon - Time: 12:30
    • -
  • Thursday, 5/25/2017 - Dbl Sat/Sh Tr of Jup - Time: 21:30
    • Europa is in transit at sunset. Then,
      2149 Io Tr begins (Dbl Sat Tr begins)
      2153 Eur Sh Tr begins
      Note: Europa's shadow will be immediately north of Io at first.
      2219 Eur Tr ends (Dbl Sat Tr ends)
      2247 Io Sh Tr begins (Dbl Sh Tr begins)
      0000 Io Tr ends
      0019 Eur Sh Tr ends (Dbl Sh Tr ends)
      0058 Io Sh Tr ends
  • Friday, 5/26/2017 - Io EcR - Time: 22:00
    • Io emerges from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter at 2213.
  • Wednesday, 5/31/2017 - Gan OcD - Time: 01:00
    • Ganymede disappears behind Jupiter's south polar region at 0110.
  • Wednesday, 5/31/2017 - Occ of rho Leo - Time: 21:00
    • At about 2109 the mag 3.8 star rho Leonis will disappear behind the moon's dark limb 79° from the south cusp. Then at about 2223 it will reappear from behind the bright limb at axis angle 264° (or 86° from the south cusp). The reappearance is challenging and requires larger aperture scopes. Rho Leo is an extremely close double, which may be detectable for those with suitable equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)

June 2017
  • Thursday, 6/1/2017 - 1st Qtr - Time: 05:30
    • -
  • Friday, 6/9/2017 - "Strawberry" Moon - Time: 06:00
    • -
  • Friday, 6/9/2017 - Jup stat - Time: 22:00
    • Jupiter ends retrograde motion.
  • Thursday, 6/15/2017 - Sat opp - Time: 03:00
    • -
  • Saturday, 6/17/2017 - Last Qtr - Time: 04:30
    • -
  • Tuesday, 6/20/2017 - Summer Solstice - Time: 21:30
    • The summer solstice occurs at 9:24pm.
  • Friday, 6/23/2017 - New Moon - Time: 19:30
    • -
  • Friday, 6/30/2017 - 1st Qtr - Time: 17:30
    • -

July 2017
  • Saturday, 7/8/2017 - "Buck" Moon - Time: 21:00
    • -
  • Sunday, 7/9/2017 - Plu opp - Time: 21:00
    • -
  • Sunday, 7/16/2017 - Last Qtr - Time: 12:30
    • -
  • Sunday, 7/23/2017 - New Moon - Time: 02:30
    • -
  • Sunday, 7/30/2017 - 1st Qtr - Time: 08:30
    • -

August 2017
  • Thursday, 8/3/2017 - Ura stat - Time: 02:00
    • Uranus begins retrograde motion.
  • Monday, 8/7/2017 - "Sturgeon" Moon - Time: 11:00
    • -
  • Saturday, 8/12/2017 - Perseids Peak - Time: 12:00
    • This is a very unfavorable year for Perseid meteor viewing with a gibbous moon during morning hours and the peak predicted during daylight hours locally.
  • Monday, 8/14/2017 - Last Qtr - Time: 18:00
    • -
  • Monday, 8/21/2017 - Solar Eclipse - Time: 09:00
    • An 82% partial solar eclipse occurs from 9:01 to 11:37am with the eclipse maximum at 10:15. These values are calculated for the RFO site (using Occult4) and differ as distance from RFO increases. WARNING: Use approved safe viewing methods to observe the eclipse to avoid eye damage or blindness. A total solar eclipse occurs for those along a path that runs across the U.S. through or very near Salem OR, St. Louis MO, Nashville TN, and Charleston SC.
  • Monday, 8/21/2017 - New Moon - Time: 11:30
    • -
  • Friday, 8/25/2017 - Sat stat - Time: 07:00
    • Saturn ends retrograde motion.
  • Tuesday, 8/29/2017 - 1st Qtr - Time: 01:00
    • -

September 2017
  • Monday, 9/4/2017 - Nep opp - Time: 22:00
    • -
  • Wednesday, 9/6/2017 - "Harvest" Moon - Time: 00:30
    • -
  • Tuesday, 9/12/2017 - Last Qtr - Time: 23:30
    • -
  • Tuesday, 9/19/2017 - Ura Opp - Time: 10:00
    • -
  • Tuesday, 9/19/2017 - New Moon - Time: 22:30
    • -
  • Friday, 9/22/2017 - Autumnal Equinox - Time: 13:00
    • The autumnal equinox occurs at 1:02pm.
  • Wednesday, 9/27/2017 - 1st Qtr - Time: 20:00
    • -

October 2017
  • Thursday, 10/5/2017 - "Hunter's" Moon - Time: 11:30
  • Thursday, 10/12/2017 - Last Qtr - Time: 05:30
    • -
  • Thursday, 10/19/2017 - New Moon - Time: 12:00
    • -
  • Saturday, 10/21/2017 - Orionids Peak - Time: 04:00
    • Conditions are very favorable for the Orionid Meteor Shower. Rates of about 20 meteors per hour are expected at the peak and off-peak outbursts are possible.
  • Friday, 10/27/2017 - 1st Qtr - Time: 15:30
    • -

November 2017
  • Friday, 11/3/2017 - "Beaver" Moon - Time: 10:30
  • Sunday, 11/5/2017 - DST Ends - Time: 02:00
    • -
  • Friday, 11/10/2017 - Last Qtr - Time: 12:30
    • -
  • Friday, 11/17/2017 - Leonids Peak - Time: 08:30
    • While moon conditions are very favorable, meteor activity is expected to be low this year with only about 10 per hour at the peak, which is likely in daylight hours locally. But unexpected activity is always possible. Meteors are viewable after midnight until about 0530.
  • Saturday, 11/18/2017 - New Moon - Time: 03:30
    • -
  • Sunday, 11/26/2017 - 1st Qtr - Time: 09:00
    • -

December 2017
  • Sunday, 12/3/2017 - "Cold" Moon - Time: 08:00
    • -
  • Saturday, 12/9/2017 - Last Qtr - Time: 24:00
    • -
  • Wednesday, 12/13/2017 - Geminids Peak - Time: 22:30
    • Conditions are highly favorable for this strong meteor shower with rates of about 120 meteors per hour lasting for a long time around the peak. The meteors are viewable all night. The crescent moon rises at about 4am on 12/14, interfering somewhat.
  • Sunday, 12/17/2017 - New Moon - Time: 22:30
    • -
  • Thursday, 12/21/2017 - Winter Solstice - Time: 08:30
    • The winter solstice occurs at 8:28am.
  • Friday, 12/22/2017 - Ursids Peak - Time: 07:00
    • Conditions are very favorable for this modest meteor shower with about 10 per hour at peak, though there have been rare outbursts of up to 50. The meteors are viewable all night until after twilight starts around 6am.
  • Tuesday, 12/26/2017 - 1st Qtr - Time: 01:30
    • -

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