MOON PHASES
Full*: July 7, 3:21 a.m.
Last quarter: July 15, 3:53 a.m.
New: July 21, 8:35 p.m.
First quarter: July 28 4:00 p.m.
*July’s full moon is often called the “Thunder Moon,”marking the summer thunderstorm season or the “Buck Moon,” when new antlers appear on buck deer.
IN HISTORY
July 4, 1054 – Light from a supernova reaches Earth and is recorded by Chinese astronomers. The Crab Nebula (Messier 1) is its remnant gas cloud.
July 6, 1687 – Publication of Isaac Newton’s Principia, which contained his three laws of motion.
July 16, 1994 – The first of the “String of Pearls” fragments of Comet Shoemaker-Levy 9 hits Jupiter. The impacts continued for about a week, and the disruption in the planet’s atmosphere could be seen for months in large telescopes.
July 20, 1969 – Neil Armstrong and Buzz Aldrin land on the moon.
July 20, 1976 – The U.S. probe Viking 1 sends back the first photos from the surface of Mars.
At 8 p.m. MDT on July 1, Earth will be at the point in its orbit farthest from
the sun (aphelion).Of course, it's our planet's ever-shifting axis, not its point in the orbit that's responsible for
the seasons. Since we in the northern hemisphere are tilted more directly toward the sun this time of year, it's our
summer, all nice and toasty.
Barring an evening thunderstorm, the nights are clear and as warm as they get
in these parts, and each night is getting a little longer ? plenty of viewing opportunities.
Paul Derrick, a fellow columnist whose paths crossed with mine a few years ago
at Big Bend National Park ? one of the best places in the country for stargazing ? likes to play with the
constellations. He has his own set of memory keys for locating those constellations and prominent stars. Being a
Rockies fan, I've been particularly taken with his "Cosmic Baseball Region."
Home is Arcturus in Boötes; Spice (in Virgo) is first base; Denebola (Leo) is
second; and Cor Caroli (Canes Venatici) is third. You can find this "diamond" upside down (Arcturus highest) in the
western sky around 11 p.m. At magnitude 2.8, Cor Caroli is the faintest of the "bases."
Paul elaborates on the celestial "field of dreams" at considerable length in
his book, A Beginner's Guide To Learning the Night Sky. You can find out more on his Web site at
stargazerpaul.com.
Saturn will be throwing a bit of a curve for observers trying to identify the
diamond since it hovers just below Denebola. Arcturus and Spica are slighter brighter, but Saturn stands out near the
horizon.
While you're gazing around that region after the end of evening twilight, see
if you can spot the faint but lovely Whirlpool Galaxy (M51) in Canes Venatici. It's about a fourth of the way between
Alkaid, the end of the Big Dipper's handle, and the aforementioned Cor Caroli.
Derrick's diamond may be a little hard to discern, but there's no mistaking the
Summer Triangle. It stands high in the eastern sky in the evening. It's bounded by three of the sky's brightest
stars, Vega in Lyre, Altair in Aquila and Deneb in Cygnus. Centered in the Milky Way, numerous deep space objects can
be seen nearby. There's the Ring Nebula (M57) in Lyre, the Wild Duck Cluster (M11) in Aquila, and the beautiful
double star Alberio in Cygnus.
By the middle of July, Jupiter, in Capricornus, rises around 10 p.m. Shining at
magnitude minus 2.8, it'll be hard to miss and will be quite visible in morning twilight prior to sunrise. It'll be
highest in the southern sky around 3 a.m. The waning gibbous moon will be nearby on the night of July 9/10.
Venus and Mars can be seen low in the east in the predawn hours. Venus, of
course, is much brighter (magnitude minus 4.1) than Mars (magnitude 1.1). The two are in Taurus, near the Pleiades
star cluster and the Hyades asterism.
You can detect Venus' movement from night to night relative to the Hyades. It
will be especially notable on the 12th and 13th. Mars is above Venus but follows its path pass the Hyades later in
the month. Being of similar magnitude, it will look like a twin of the nearby red giant star Aldebaran.
The Delta Aquarid meteor shower peaks on the morning of July 28. The moon won't
interfere, so have a look
Email this article