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

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 - Io OcD - Time: 00:30
    • Io disappears behind Jupiter at 0032.
  • 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 - 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 - Io OcD - Time: 02:00
    • Io disappears behind Jupiter at 0222.
  • Thursday, 6/1/2017 - 1st Qtr - Time: 05:30
    • -
  • Thursday, 6/1/2017 - Dbl Sat/Sh Tr of Jup - Time: 22:00
    • 2218 Eur Tr begins
      2338 Io Tr begins (Dbl Sat Tr begins)
      0031 Eur Sh Tr begins
      0042 Io Sh Tr begins (Dbl Sh Tr begins)
      0046 Eur Tr ends (Dbl Sat Tr ends)
      0149 Io Tr ends
      0252 Io Sh Tr ends (Dbl Sh Tr ends)
      0256 Eur Sh Tr ends
  • Friday, 6/2/2017 - Io EcR - Time: 24:00
    • At 0008 (on 6/3) Io emerges from Jupiter's shadow 0.4 Jupiter diameter east of Jupiter.
  • Saturday, 6/3/2017 - Ven GEW - Time: 06:00
    • Venus is at greatest elongation west in the morning sky.
  • Saturday, 6/3/2017 - Dbl Sh Tr of Jup & Eur EcR - Time: 21:00
    • The shadows of Io and Ganymede are in transit as Jupiter becomes visible in twilight.
      2121 Io Sh Tr ends (Dbl Sh Tr ends)
      2136 Europa reappears from Jupiter's shadow 0.7 Jupiter diameter east of Jupiter
      2138 Gan Sh Tr ends
  • Saturday, 6/3/2017 - Mn Vnr Jup - Time: 22:00
    • -
  • Friday, 6/9/2017 - Dbl Sat Tr of Jup - Time: 00:30
    • 0046 Eur Tr begins
      0128 Io Tr begins (Jupiter's altitude now 13° in WSW)
      Jupiter sets with both transits in progress.
  • Friday, 6/9/2017 - "Strawberry" Moon - Time: 06:00
    • This is the smallest full moon of 2017.
  • Friday, 6/9/2017 - Jup stat - Time: 22:00
    • Jupiter ends retrograde motion.
  • Friday, 6/9/2017 - Io OcD - Time: 22:30
    • Io disappears behind Jupiter at 2240. (It will reappear from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter at 0203, by which time Jupiter is low in the west, as calculated for the RFO site.)
  • Friday, 6/9/2017 - Mn nr Sat - Time: 22:00
    • -
  • Saturday, 6/10/2017 - Io Sat/Sh Tr, Gan Sh Tr & Eur EcR - Time: 21:30
    • The Io transits are in progress as Jupiter becomes visible in twilight.
      2207 Io Tr ends
      2315 Io Sh Tr ends
      2319 Gan Sh Tr begins (north polar region)
      0010 Europa reappears from Jupiter's shadow 0.7 Jupiter diameter east of Jupiter
      0136 Gan Sh Tr ends
  • Tuesday, 6/13/2017 - Occ of pi & rho Cap - Time: 02:30
    • At 0252 the mag 5.1 star pi Capricorni will reappear from behind the moon's dark limb at axis angle 238° (or 58° from the south cusp). At 0410 mag 4.9 rho Cap reappears from behind the dark limb at axis angle 314° (or 46° from the north cusp). Pi Cap is an extremely close double and very close triple. Rho Cap is a very close double. Thus, both events may be non-instantaneous for those with proper equipment. (Calculated using Occult4 for the RFO site. Details will differ as distance from RFO increases.)
  • Thursday, 6/15/2017 - Sat opp - Time: 03:00
    • Saturn is at opposition in Ophiuchus, reaching magnitude 0.0, a disk diamter of 18", ring diameter of 42", and ring tilt of 27°. Saturn's rings are now at maximum tilt, which will decrease in coming years.
  • Friday, 6/16/2017 - Nep stat - Time: 16:00
    • Neptune, in Aquarius, begins retrograde motion.
  • Saturday, 6/17/2017 - Io OcD - Time: 00:30
    • Io disappears behind Jupiter at 0032.
  • Saturday, 6/17/2017 - Last Qtr - Time: 04:30
    • -
  • Saturday, 6/17/2017 - Io Sat/Sh Tr, Gan Tr & Eur OcD - Time: 21:30
    • 2147 Io Tr begins (in late civil twilight)
      2153 Eur disappears behind Jupiter
      2216 Gan Tr begins (north polar region) Dbl Tr begins
      2259 Io Sh Tr begins
      2359 Io Tr ends - Dbl Tr ends
      0048 Gan Tr ends
      0110 Io Sh Tr ends
  • Sunday, 6/18/2017 - Io EcR - Time: 22:00
    • At 2227 Io reappears from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter.
  • Tuesday, 6/20/2017 - CrMn nr Ven - Time: 04:00
    • -
  • Tuesday, 6/20/2017 - Summer Solstice - Time: 21:30
    • The summer solstice occurs at 9:24pm.
  • Friday, 6/23/2017 - Lrg Tides thru 6/25 - Time: 00:00
    • Large tides due to new moon occurring 16 hours before perigee.
  • Friday, 6/23/2017 - New Moon - Time: 19:30
    • -
  • Saturday, 6/24/2017 - Io Sat/Sh Tr & Eur OcD - Time: 23:30
    • 2340 Io Tr begins
      0023 Eur disappears behind Jupiter
      0054 Io Sh Tr begins with Jupiter low in WSW
  • Sunday, 6/25/2017 - Io EcR - Time: 24:00
    • Io reappears from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter at 0022 on 6/26.
  • Monday, 6/26/2017 - Eur Sh Tr - Time: 21:30
    • Note: An Io Sh Tr and Eur Tr end within 10 minutes prior to the start of this event, which is during nautical twilight.
      2142 Eur Sh Tr begins
      0006 Eur Sh Tr ends
  • Tuesday, 6/27/2017 - CrMn vnr Regulus - Time: 22:00
    • The crescent moon is very near the very bright blue star Regulus in Leo. Use binoculars to appreciate this colorful sight.
  • Wednesday, 6/28/2017 - Gan Ec - Time: 21:30
    • This event will have several interesting aspects worthy of mention. Observation should start around 9pm, or as early as you can spot Jupiter in the sky (it will be high in the SW). Io is by itself west of Jupiter, and Callisto, Ganymede and Europa form a nice triangle to the east, with Europa furthest east. The tilt of the satellites' orbital plane is evident: Callisto and Io are in front of Jupiter moving west and thus north of Jupiter's equator. Ganymede and Europa are behind Jupiter moving east and well to the south. Ganymede will now pass totally through Jupiter's shadow:
      2130 Gan disappears 0.7 Jupiter diameter east
      2346 Gan reappears 1.3 Jupiter diameter east
  • Friday, 6/30/2017 - 1st Qtr - Time: 17:30
    • -
  • Friday, 6/30/2017 - Mn vnr Jup - Time: 23:00
    • -

July 2017
  • Sunday, 7/2/2017 - Juno opp - Time: 06:00
    • The minor planet Juno is at opposition in Scutum at 10th magnitude. A finder's chart is essential.
  • Sunday, 7/2/2017 - Io OcD - Time: 22:30
    • Io disappears behind Jupiter at 2248.
  • Monday, 7/3/2017 - Io/Eur Sat/Sh Tr - Time: 21:00
    • Io is in transit at sunset. Then,
      2117 Io Sh Tr begins
      2142 Eur Tr begins, near Io's Sh
      - Begin double transit
      2214 Io Tr ends
      - End double transit
      2327 Io Sh Tr ends
      0019 Eur Tr ends
      0019 Eur Sh Tr begins, though by this time Jupiter's altitude is only 8° (at RFO).
  • Wednesday, 7/5/2017 - Gan OcR - Time: 22:30
    • Ganymede reappears from behind Jupiter's southeast polar region at 2245.
  • Thursday, 7/6/2017 - Mn nr Sat - Time: 22:00
    • -
  • Saturday, 7/8/2017 - Mer in W thru 7/29 - Time: 21:00
    • Mercury provides a poor evening apparition reaching a maximum altitude 45 minutes after sunset (at RFO's latitude) of only 6° on 7/21.
  • Saturday, 7/8/2017 - "Buck" Moon - Time: 21:00
    • -
  • Sunday, 7/9/2017 - Plu opp - Time: 21:00
    • Pluto is at opposition at mag 14.2 in Sagittarius. A finder's chart and large aperture is essential for this very challenging target.
  • Monday, 7/10/2017 - Io Sat/Sh Tr - Time: 21:30
    • 2157 Io Tr begins
      2312 Io Sh Tr begins
      0008 Io Tr ends, with Jupiter now only 5° high (at RFO). Jupiter sets with Io's shadow in transit.
  • Tuesday, 7/11/2017 - Io EcR - Time: 22:30
    • At 2242 Io reappears from Jupiter's shadow 0.5 Jupiter diameter east of Jupiter.
  • Wednesday, 7/12/2017 - Eur OcR/Ec - Time: 21:00
    • At 2118 Europa reappears from behind Jupiter's SE limb. Then, very shortly thereafter, at 2121, Europa disappears into Jupiter's shadow VERY close to Jupiter's limb. At 2344 Europa reappears 0.8 Jupiter diameter east of Jupiter, by which time Jupiter's altitude is only 8° (at RFO). Ganymede approaches Jupiter's SW polar limb during these events and is occulted just before Jupiter sets (at RFO).
  • Sunday, 7/16/2017 - Last Qtr - Time: 12:30
    • -
  • Thursday, 7/20/2017 - CrMn vnr Ven - Time: 04:30
    • The crescent moon is very near Venus, with the bright red-orange star Aldebaran and the Pleiades cluster above this pair and slightly south.
  • Sunday, 7/23/2017 - New Moon - Time: 02:30
    • -
  • Wednesday, 7/26/2017 - Io Sat/Sh Tr - Time: 21:30
    • Io is in transit at sunset.
      2130 Io Sh Tr begins
      2230 Io Tr ends
      Jupiter sets with Io's shadow in transit.
  • Friday, 7/28/2017 - Eur Sat/Sh Tr - Time: 21:30
    • Europa is in transit at sunset.
      2130 Eur Sh Tr begins
      2232 Eur Tr ends
      Jupiter sets with Europa's shadow in transit.
  • Friday, 7/28/2017 - Mn nr Jup - Time: 22:00
    • -
  • Sunday, 7/30/2017 - 1st Qtr - Time: 08:30
    • -

August 2017
  • Wednesday, 8/2/2017 - Mn vnr Sat - Time: 23:00
    • -
  • Thursday, 8/3/2017 - Ura stat - Time: 02:00
    • Uranus begins retrograde motion in Pisces.
  • 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
    • -
  • Wednesday, 8/16/2017 - CrMn Vnr Aldebaran - Time: 02:30
    • The crescent moon is VERY near the bright red-orange star Aldebaran. Use binoculars to appreciate the colorful star next to the moon.
  • Friday, 8/18/2017 - CrMn nr Ven - Time: 05:00
    • -
  • Saturday, 8/19/2017 - CrMn nr Ven - Time: 05:00
    • -
  • 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
    • -
  • Thursday, 8/24/2017 - Cr Mn nr Jup - Time: 20:30
    • -
  • Friday, 8/25/2017 - Sat stat - Time: 08:00
    • Saturn ends retrograde motion in Ophiuchus.
  • Tuesday, 8/29/2017 - 1st Qtr - Time: 01:00
    • -
  • Tuesday, 8/29/2017 - Mn nr Sat - Time: 21:30
    • -

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
    • -

Back to top of page