SkyEye

The Calendar

Sadly, the famous Perseid meteor shower is washed out by moonlight this year. By way of compensation, Saturn is at opposition in August and on display all night and Mercury puts on its best evening show for equatorial and southern observers.

The Solar System

The word planet is derived from the Greek word for 'wanderer'. Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars. Dwarf planets and small solar-system bodies, including comets, are not so constrained, often moving far above or below the ecliptic.

Sun Cancer → Leo

Mercury Leo → Virgo

For southern hemisphere planet watchers, this is the best evening apparition of Mercury this year as it climbs relatively high above the western horizon. Observers farther north are not so lucky, with the tiny planet never gaining much altitude. Mercury appears only 0.6° away from first-magnitude star Regulus on 4 August. The tiny planet reaches aphelion on 23 August and greatest elongation east (at 27.3°, its the largest of the year) four days later. By the end of the month, Mercury is descending back toward the horizon.

Venus Gemini → Cancer → Leo

Having passed through its descending node in April, Venus returns to the north side of the ecliptic on the second day of the month. The morning star is getting low in the east for all observers so its encounter with the Beehive Cluster (M44) on 17 August will be difficult to see.

Earth and Moon

Light from the Full Moon obliterates the Perseids this year. Our satellite continues its series of occultations of Uranus, with the green ice giant vanishing behind the Moon's disk on 18 August.

Mars Aries → Taurus

Mars completes its tour of the gas giants this month when it overtakes sixth-magnitude Uranus on the second day of the month. On 27 August the red planet reaches west quadrature. A telescopic view of the planet will show a distinctly gibbous disk just under ten arc-seconds in width. Mars rises during the late evening hours for astronomers in northern temperate latitudes but does not appear until after midnight for planet watchers in the southern hemisphere.

Jupiter Cetus

Jupiter continues to rise ever earlier in the evening as it heads toward opposition next month. The dark winter skies of the southern hemisphere offer the best viewing opportunities but Jupiter now appears in the east during evening twilight for observers farther north.

Saturn Capricornus

At opposition mid-month, Saturn is visible all night, rising at sunset and setting at sunrise. It shines at magnitude +0.3 and presents an orb 18.8 arc-seconds in diameter when viewed through a telescope. With the rings (now tilted at 13.9°), it is nearly 43° across.

Uranus Aries

It's a busy month for the green ice giant which is now rising before midnight at all latitudes. The red planet passes by on the second day of the month and the waning gibbous Moon occults the sixth-magnitude object on 18 August. However, only those treading water in the northern Pacific Ocean will witness it. Uranus reaches west quadrature on 11 August and reaches a stationary point (in right ascension) on 24 August, after which it goes into retrograde.

Neptune Pisces → Aquarius

A small telescope is necessary to view the most distant planet in the solar system. Still in retrograde leading up to next month's opposition, Neptune is best viewed from the southern hemisphere where it rises in early evening and is visible the rest of the night. Observers in northern latitudes are getting a better chance of glimpsing the eighth-magnitude planet as it now rises mid-evening and is well aloft once the sky gets dark late at night.