Greetings from RFO (www.rfo.org). Jupiter continues to be bright and dominant, spending the first half of the month very near the star Zubenelgenubi, and Saturn reaches opposition late in the month, though its far southerly declination is a problem for us northerners. Venus continues decorating the evening sky though will gradually stay lower in the west and thus become slightly less prominent. Mercury begins a somewhat good evening apparition in the second half of the month.
JUNE ASTRONOMY EVENTS TO WATCH FOR - Note: All times are local Pacific Time and calculated for the RFO site.
* Use the "What's Up in the Night Sky" link on our website for additional events and details.
Moon - The moon is very near Saturn around 12am on the morning of 6/1. The moon is near Mars around 4am on 6/3. Last Quarter is midday on 6/6. New Moon is midday on 6/13. Look for a very thin 2.8% crescent moon 6° high 27° north of due west 30 minutes after sunset on 6/14 (which is at 9:05pm calculated for the RFO site). The crescent moon is near Venus around 9:30pm on the evenings of 6/15 and 6/16. The moon is very near the bright blue star Regulus in Leo around 11pm on 6/17 (use binoculars to appreciate the color). The first quarter moon is on the morning of 6/20. The moon is near Jupiter around 9pm on 6/23. The "Strawberry" full moon is at 10pm on 6/27 and will be VERY near Saturn at opposition that same day, a reminder that opposition is the planetary equivalent of a full moon (opposite side of Earth from the sun). The moon is again near Mars around midnight on the evening of 6/30.
Mercury - After superior conjunction on 6/5, Mercury provides a moderately good evening apparition from about 6/19 to 7/17 with a maximum altitude 45 minutes after sunset of 8° on 7/5. Mercury will be brightest during June, fading during early July so more difficult to spot then.
Venus - Venus is still prominent in the evening sky but becoming slightly less so as it rises less high each evening. Nevertheless, it sets around 11pm all month. The crescent moon joins Venus around 9:30pm on the evenings of 6/15 and 6/16. Venus will be VERY near the large bright open star cluster Praesepe (M44) in Cancer around 10pm on 6/19. Try using binoculars: Venus will be very bright compared with the star cluster.
Mars - In Capricornus, Mars rises around 11:30pm mid-month and begins retrograde motion on 6/28 as it approaches opposition in late July. It is at about magnitude -2.5 mid-month and now at its best for telescope observing (in the wee a.m. hours), though the southerly declination is less than ideal for us northerners. The Moon is near Mars around 4am on 6/3 and again around midnight on 6/30.
Jupiter - Jupiter, retrograde in Libra and very bright and dominant in the night sky, is just past opposition so still very near its best for observing and more conveniently prominent in the p.m. hours, setting around 3:30am mid-month. It spends the first half of the month very near the bright wide double star Zubenelgenubi (alpha Librae). Together, these should make a lovely binocular target. The pair is closest around 6/7. The moon is near Jupiter around 9pm on 6/23. Jovian satellite events are now readily observable with details on these on our website(*). An interesting example is the Io and Ganymede eclipse reappearances on the evening of 6/7 (see below).
Saturn- Saturn, retrograde in Sagittarius, rises around 9:30pm mid-month and reaches opposition on 6/27 when it will be at magnitude 0.0 and a disk size of 18.4" with a ring diameter of 42" and a near maximum tilt of 27°. Its far southerly declination provides just a short window for the best observing of this favorite of targets this year. The moon is very near Saturn around midnight on the morning of 6/1. Then, the full moon joins Saturn at opposition with the pair closest around 10pm on 6/27.Neptune - In Aquarius, Neptune begins retrograde motion on the 19th. Rising around 1am, it is not yet a convenient observing target for most!
Vesta at Opposition - This minor planet (aka "asteroid") is at opposition in Sagittarius on 6/19 when it will be at magnitude 5/3. The opposition R.A./Dec coordinates are about 17h52m/-19°48'. This is about 2.5° northeast of the star 58 Oph.
Io and Ganymede Eclipse Reappearances - Note that for those of us near RFO this event begins in nautical twilight with Jupiter bright in the south-southeast. Try to get Jupiter in your scope view by 9pm. At 9:21pm Io will emerge from Jupiter's shadow about 0.25 Jupiter diameter east of Jupiter, with Callisto to the southeast of the newly appearing Io. Ganymede lies between these two but is still in Jupiter's shadow (since it orbits further from Jupiter and Jupiter's shadow now angles to the east) so is not visible. Then, at 9:57, Ganymede will emerge from the shadow, revealing itself between the other two.
Summer Solstice - The solstice occurs at 3:07 am on 6/21.
TIME SEQUENCE SUMMARY OF EVENTS: Capitalized items refer to the sections above.
TIME SEQUENCE SUMMARY OF EVENTS:
Capitalized items refer to the sections above.
6/01 - MOON very near SATURN
6/03 - MOON near MARS
6/06 - Last Quarter MOON
6/07 - IO AND GANYMEDE ECLIPSE REAPPEARANCES
6/07 - JUPITER near Zubenelgenubi
6/13 - New MOON
6/14 - 2.8% Crescent MOON in west
6/15 - Crescent MOON near VENUS
6/16 - Crescent MOON near VENUS
6/17 - MOON very near Regulus
6/19 to 7/17 - MERCURY in the west
6/19 - NEPTUNE begins retrograde motion
6/19 - VESTA AT OPPOSITION
6/19 - VENUS Very near Praesepe (M44)
6/20 - First Quarter MOON
6/21 - SUMMER SOLSTICE
6/23 - MOON near JUPITER
6/27 - SATURN at opposition
6/27 - "Strawberry" Full MOON
6/27 - Full MOON Very near SATURN
6/28 - MARS begins retrograde motion
6/30 - MOON near MARS