Tuesday, August 10 – Crescent Moon near Venus (after sunset)
Look just above the western horizon after sunset on Tuesday, August 10 to see the young crescent Moon shining a palm’s width to the right (or 6.5 degrees to the celestial northwest) of the extremely bright planet Venus. On the following evening, the orbital motion of the Moon will shift it a similar distance to Venus’ upper left (celestial east). During August, the greatly tilted ecliptic (green line) will prevent Venus from climbing very high for mid-Northern latitude skywatchers.
Thursday, August 12 – Perseids Meteor Shower peak (pre-dawn)
The spectacular Perseid Meteor Shower, which runs between July 17 and August 26 every year, will peak during mid-day in the Americas on Thursday, August 12. That means that the best time for seeing the most Perseids meteors in North America will be the hours before dawn on Thursday morning, when the shower’s radiant in Perseus will be highest in the northeastern sky. This is the most popular shower of the year, delivering up to 100 meteors per hour at the peak. Derived from debris dropped by Comet 109P/Swift-Tuttle, many Perseids are extremely bright and leave persistent trails. Although fewer meteors are seen before and after the peak, skywatchers can also expect to see plenty of meteors on Wednesday, Thursday, and Friday night. To enjoy meteor showers, find a safe rural location with plenty of open sky and just look up. This year, the young crescent Moon will set shortly after sunset on the peak date, leaving the whole night dark for meteor-watching.
Sunday, August 15 – First quarter Moon (at 15:19 GMT)
When the Moon completes the first quarter of its journey around Earth on Sunday, August 15 at 11:19 a.m. EDT or 15:19 GMT, its 90 degree angle away from the Sun will cause us to see the Moon half-illuminated on its eastern side. At first quarter, the Moon always rises around mid-day and sets around midnight, so it is also visible in the afternoon daytime sky. The evenings surrounding first quarter are the best ones for seeing the lunar terrain when it is dramatically lit by low-angled sunlight, especially along the terminator, the pole-to-pole boundary between the lit and dark hemispheres.
Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the Universe together.