Australian Sky Telescope MayJune 2017

46 AUSTRALIAN SKY & TELESCOPE May | June 2017

SUN, MOON & PLANETS by Jonathan Nally

Venus and Saturn delight tonight

Saturn reaches opposition as Venus shines in the morning sky.

M

ay begins with Mercury to

the east in the pre-dawn sky.

The planet will reach greatest

elongation (ie. largest angle) from the

Sun on May 18, making this month a

good time to observe it. Watch for the

thin crescent Moon nearby on May 24.

During June, Mercury will begin to slide

down toward the horizon as each day

passes, finally vanishing from view by the

end of the third week as it goes disappears

around the other side of the Sun.

Venus rises between 3:00am and

4:00am during May and June, and

reaches its greatest western elongation

of 46 degrees on June 3. Watch for the

Moon nearby on May 23 and June 21.

See if you can spot Uranus less than 2

degrees from Venus on June 3 and 4 —

binoculars should be all you need.

Marsislowonthewesternhorizon

aftersunsetduringMayandJune,

slowly dropping lower in the sky. By

the end of June it will have become too

close to the Sun to be seen, and we’ll

have to wait until September for it to

reappear in our morning skies. By the

way, Mars will experience its equinox

on May 5, so on that day please spare a

thought for those intrepid NASA rovers.

Jupiter is still very well placed

for observation during the evening,

having reached opposition (ie. when

the Sun and the planet are in opposite

directions as seen from Earth) in April.

Binoculars will show its four major

moons, while even a small telescope

will reveal its cloud patterns.

Saturn will reach opposition on June

15, making it the star of the show for

evening stargazers all through May and

June. The ringed planet will be easily

seen in the eastern sky, rising shortly

aftersunset.LookfortheMoonclose

byonMay13andJune9.Saturn’s

ringsaretiltednicelytowardusatthe

moment, so reward yourself by getting

in some telescopic observations.

There’ll be an occultation of Regulus

by the Moon on the evening of May 4,

visible across most of Australia. The star

will wink out as the dark limb of the

Moon overtakes it, and reappear about

80 minutes later on the bright limb.

Disappearance times (in local time) for

capital cities are as follows: Adelaide

(7:24pm), Brisbane (8:14pm), Canberra

(8:11pm), Hobart (8:19pm), Melbourne

(8:09pm) and Sydney (8:14pm). Perth

will miss the start of the event, but will

catch the end (6:01pm) in the twilight.

For those in Darwin, the disappearance

will occur at sunset, with reappearance

at the end of twilight (8:05pm).

Finally, Earth will reach the solstice

on June 21 at 2:00pm Australian Eastern

Standard Time. For us in Australasia this

isthewintersolstice,andiswhenthe

Sunisatitsfurthestdeclinationsouth.

S Left: Saturn rides high in the evening sky, heading toward opposition in June. Middle: Venus, Mercury and the Moon will gather i n the dawn sky

in late May. Right: Venus will remain the ‘morning star’ for most of this year.