Saturday:
Regulus, the brightest star in the constellation Leo the lion is less than a
fist held upright and at arm’s length above the moon at 9 p.m. They are midway
up in the southern sky.
Sunday: Remember
the old saying: April showers bring… meteors. The Lyrid meteor shower peaks
tonight. The meteors appear to come from a point to the right of the bright
bluish star Vega in the constellation Lyra the lyre. This point is about three
fists held upright and at arm’s length above the east-northeast horizon at
midnight tonight and close to straight overhead near dawn. The best time to
look is just before dawn since that is when the radiant, or point from which
the meteors appear to come, is high in the sky. This year, the Moon is in the
waxing gibbous phase meaning it will be bright and be out for most of the
night. Typically, this is one of the least interesting major meteor showers of
the year. However, it is also one of the most unpredictable. As recently as
1982, there were 90 meteors visible during a single hour. In addition, the
Lyrid meteor shower has historical interest because it was one of the first
ones observed. Chinese records say “stars fell like rain” in the shower of 687
B.C. As your Mother might say, dress warm and sit in a comfortable chair for
maximum enjoyment. Meteors are tiny rocks that hit the Earth and burn up in the
atmosphere.
Monday: You
know Metis and Thebe and Adrastea and Amalthea. Io and Ganymede and Callisto
and Europa. But do you recall? There are 67 Jovian moons in all. (As of July
2012.) Less than 50 years ago, Jupiter was thought to have only 12 moons. But,
astronomers are red-nosed with delight that the advent of supersensitive
electronic cameras has caused the number of discovered moons to rapidly
increase. Jupiter’s 67 moons range in size from Ganymede, with a diameter of
5,262 kilometers, to S/2002 J12 and S/2003 J9, with a diameter of only one
kilometer. Our moon has a diameter of 3,475 kilometers. (One kilometer is 0.62
miles.) Saturn is second place in the moon race with 62. Uranus is next with
27. Then comes Neptune with 13, Mars with 2, and Earth with 1. Even dwarf
planets have moons. Pluto has 5, Eris has 1, and Haumea has 2. Eris is an outer
solar system object that was discovered in 2005 and named in September of 2006.
Because astronomers thought it was larger than Pluto, people called it the
tenth planet for a while. (More recent measurements show Eris to be a little
smaller than Pluto.) Haumea, the newest dwarf planet with a moon, was
discovered in 2004 and officially named a dwarf planet on September 17, 2008. Jupiter,
the “mooning” champ, is a half a fist above the west horizon at 9 p.m. Go to http://goo.gl/Xkoeq
for more information about Solar System moons.
Tuesday: Avast
ye matey. Swab the poop deck. Pirates love astronomy. In fact, the term “poop”
in poop deck comes from the French word for stern (poupe) which comes for the
Latin word Puppis. Puppis is a constellation that represents the raised stern
deck of Argo Navis, the ship used by Jason and the Argonauts in Greek
mythology. Argo Nevis was an ancient constellation that is now divided between
the constellations Puppis, Vela and Carina. The top of Puppis is about a fist
and a half to the left of the bright star Sirius in the south-southwest sky at
9 p.m. Rho Puppis, one of the brightest stars in the constellation, is about
one and a half fists above the south-southwest horizon at this time.
Wednesday:
Jupiter is two and a half fists above the west horizon at 9 p.m.
Thursday: Tonight’s
full moon is called the Full Pink Moon because it marks the appearance of moss
pink, one of the first spring flowers.
Friday: Saturn
is one and a half fists above the southeast horizon at 10 p.m.
The
positional information in this column about stars and planets is typically
accurate for the entire week.
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