Astronomy news for the two weeks starting Friday, May 22,
2015.
The next skylights will appear June 5, 2015.
We begin the new fortnight with the Moon shining as a fat waxing crescent not far from first quarter, the phase passed on Monday,
May 25, about the time of its daylight rise. It then brightens
through waxing gibbous to full Moon on Tuesday, June 2, with the Moon
out of sight. That evening, the Moon will rise a bit past the
full phase as it begins fading through the waning gibbous phase. The night of
Saturday the 23rd the Moon will pass five degrees south of Jupiter, the two making a fine sight. By the following
night the Moon will appear south of the line connecting Jupiter
and Leo's Regulus. Then look to see the
nearly full Moon to the northwest of Saturn the night of the 30th, to the northeast
of it the following night. Our companion passes apogee, where it is farthest from Earth, 5.5 percent
more distant than average, on Tuesday the 26th, just a day after
first quarter.
As twilight deepens, Venus
remains brilliant in the west, the planet not setting until
after 11:30 PM Daylight Time. As the month changes, Venus appears
to the left of Castor and Pollux in Gemini. Our session ends with Venus just a day shy of
its greatest eastern elongation, 45 degrees east of the Sun, when it will
appear half illuminated quite like a half-Moon when it is at the
first or third quarter of its orbit. The phases of Venus
constitute one of the classic Galilean proofs that the planets go
around the Sun, not the Earth. About a week before, on Saturday
the 30th, Mercury passes inferior conjunction with the Sun as it
goes from being an evening to a morning planet.
That leaves us with Jupiter and Saturn. In western evening skies,
Jupiter, maintaining its position to the west of the Sickle of Leo, now sets around local
midnight. With Venus more or less fixed, the giant planet draws
ever closer to it as the two brightest of planets prepare for a
close passage in late June/early July (formal conjunction taking
place July 1). About as Jupiter sets, Saturn rises north of Antares in Scorpius. The telescope shows Saturn's rings to be "open," tilted as much
toward the observer as possible, which makes the planet especially
bright.
Following the curve of the Big
Dipper's handle to the south
leads you to bright Arcturus,
then on to Spica in Virgo. To the right of Spica, is
a distorted box that makes the ancient constellation of Corvus, the Crow or Raven.
Further to the west is the dim figure of Crater, the Cup, both of them riding the back of Hydra, the Water Serpent. As the
front bowl stars of the Dipper point to Polaris, so the top two stars of
Corvus point back, to the east, toward Spica, completing the loop.
