Astronomy news for the week starting Friday, May 30, 2014.
The Moon spends nearly the entire week in the waxing crescent phase, each evening climbing higher
as dusk settles in. Early in the week, look for the glow of Earthlight on the nighttime side of
the Moon, which allows the whole lunar disk to be seen. From the
Moon, the near full Earth is
far brighter than the full Moon as seen
from Earth. You would have no trouble reading a book, providing
of course you had a space suit with you, as the Moon has
practically no air: its gravity is not strong enough to hold an
atmosphere. The crescent phase is terminated at first quarter, which takes place the
afternoon of Thursday, June 5, with the Moon climbing the eastern
sky in daylight, giving a chance to see the exact phase.
The evening of Friday, May 30, the thin crescent will fall well
Jupiter and to the left of Mercury, which lets the
smallest planet (barring Pluto, which is another story) to be easily
identified. The evening of Saturday the 31st, the crescent will
be below Jupiter, then the following evening find it up and to the
left of the giant planet.
Jupiter's bright light, which has dominated the evening for so
long, is slowly disappearing. Still in Gemini south of Castor and Pollux, Jupiter now sets toward the
northwest just half an hour after the end of twilight. The sky
then belongs to Mars and Saturn.
Transiting the meridian to the
south shortly after sunset, the red planet, well to the northwest
of the star Spica, spends the rest
of the night in southwestern skies, finally setting around 2:30
AM. Though Mars has dimmed quite a lot since its opposition to the
Sun in early April, it's still brighter than all but the top three
stars, Sirius, Canopus, and Alpha Centauri. Still on center stage, Saturn is
up pretty much all night. In central Libra, it crosses to the south about half an hour
before midnight Daylight Time, and does not set until morning
twilight lights the sky, by which time Venus is up low in the east. On the other side
of the sky, Mercury is briefly visible in twilight to the right of
the crescent Moon the evening of Friday, May 30.
Two icons are paired in northern and southern evening skies. From
mid-northern latitudes, the Big
Dipper rides high, while in cognate southern latitudes, Crux, the Southern Cross, does the
same. Between the two, falling across both the celestial equator and the ecliptic, is Virgo, which encompasses Mars.