The moon approaches third-quarter phase as the month begins, meaning it’s a third of the way through the lunar month, or a little over 22 days since new moon.
The minor planet Juno is occulted Aug. 4, visible from eastern Europe, Scandinavia, western Russia and extreme northern Canada. Aug. 10, the moon reaches perigee, and tidal areas will see extreme high tides. Aug. 14, Venus is within six degrees of our satellite, Jupiter is five degrees south Aug. 17 and Saturn is two degrees south Aug. 21. The moon is full Aug. 26.
Mercury is too near the sun to be seen until mid-month, when it appears in the eastern morning sky.
Venus reaches maximum eastern elongation, but lower in the sky because of the ecliptic geometry – lower to the horizon. Telescopic viewers will see its phase change from gibbous to crescent, which observation, more than 400 years ago, led Galileo to conclude that Venus was not orbiting the Earth, but circled the sun instead.
Mars continues retrograde motion in western Capricornus, and is already fading from its nearest Earthly approach in July.
Jupiter, the gas giant, has four large moons that often come between the sun and the planet. The events are termed a “transit,” either of the moon itself, or the moon’s shadow. In the latter two-thirds of August, numerous double-shadow transits occur, beginning Aug. 9, then Aug. 13, 15, 16, 20, 22, 23, 27 and 30. The moon gets into the act Aug. 17.
Saturn is visible in the evening hours through the month, and is joined by the moon Aug. 21.
Uranus is stationary Aug. 7, and then slowly begins retrograde motion thereafter.
Neptune rises in mid-evening, still in retrograde motion in Aquarius. It’s good to remember that retrograde motion is an illusion caused by the relatively rapid motion of the Earth in its orbit. Early astronomers had a difficult time trying to resolve what they saw with the beliefs at the time – that the Earth was at the centre of the universe. Thus, they had to make up a lot of imaginary motions to account for observations.
The Perseid meteor shower peaks on the evening of Aug. 12. Expect about 90 meteors per hour under good viewing conditions.
— James Edgar has had an interest in the night sky all his life. He joined the Royal Astronomical Society of Canada in 2000 and is now the society’s past-president, editor of the Observer’s Handbook and production manager of the bi-monthly RASC Journal. The IAU named asteroid 1995 XC5 “(22421) Jamesedgar” in his honour.
