August 2011 Sky from the Keeble Observatory
As this is written, the last landing ever for the Space Shuttle has just happened.
30 years; 135 flights; two preventable tragedies with 14 deaths in flight. And,
this is also the end - for the foreseeable future – of an American launched into
space on an American space craft. For all its flaws, the Shuttle was a technical
marvel: no other vehicle, before or since, was designed and built to fly multiple
times into orbit and return crews to Earth. For an entire generation, we saw men
and women rocket into space to launch, retrieve, and repair satellites. They built
the International Space Station. They did some (not a lot, admittedly) important
science, mostly about the physiological effects of going into a “weightless” environment.
That we do not have a replacement vehicle I attribute to a lack of clear vision.
President Kennedy proposed that we chose to go to the Moon, not because it was easy
but because it was hard (and because we were in a “space race” with the Soviet Union).
We met that challenge. President Nixon approved the Space Shuttle – but it was a
pale echo of the proposed vehicle which would carry astronauts to a space station
to be used as a construction site to return permanently astronauts to the Moon.
The first President Bush proposed returning to the Moon, and then on to Mars … but
that proposal was unfunded and died for lack of any support in Congress. His son
proposed the “Constellation” program, which would build a successor vehicle to the
Shuttle, a new heavy lift booster, and return to the Moon by 2020 and construction
of a permanent base. His plan included terminating the Shuttle, completing and then
abandoning the International Space Station, and – oh, by the way – proposing
no funding for this project until after he left office.
President Obama changed the plan again! The current blueprint keeps us dependent
on Russian Soyuz transport to the Space Station for at least the next three years,
when it is hoped that private companies will develop a new crew vehicle. The lofty
goal is for an asteroid rendezvous and then a mission to Mars orbit.
In my opinion, the problem is with multiple and shifting visions. In Proverbs 29:18,
we read that “Where there is no vision, the people perish.” Substitute “human space
flight” for “people.” This should not be a battle between robotic space exploration
– which is exciting and valuable in its own right – and human space flight. With
vision and political will, we can do both. The country’s current fiscal mess was
not caused by the miniscule NASA budget.
On two lighter notes: NASA’s DAWN probe has gone into orbit around the main belt
asteroid 4 Vesta (4 because it was the 4th asteroid discovered), the
second largest asteroid in the asteroid belt. After a year, it will restart its
ion engine and head off to rendezvous with 1 Ceres, the largest and first-discovered
asteroid. And, using the Hubble Space Telescope, researchers have discovered a 4th
moon orbiting the dwarf planet Pluto. More on both of these next month.
Lunar phases for August: First Quarter on the 6th, at 7:08 am;
Full Moon on the 13th at 2:57 pm; Last Quarter on the 21st,
at 5:54 pm; New Moon on the 28th, at 11:04 pm.
This is the month for the annual Perseid meteor shower, which will occur 11-14 August,
with the peak expected on the 13th. The bad news is that it will be competing
with a full moon, so it may be a disappointing year. If you think you’d like to
try seeing this event, you’ll need to find a dark site away from street lights and
other outdoor illumination. Best viewing times are typically after midnight until
predawn twilight, since the Earth’s rotation will be carrying you into the meteor
Predawn planet watchers will find Mars and Jupiter to the east and southeast. Early
in August, Mars rises about 3 hours before sunup – it will look like a moderately
bright, reddish “star” about 30 degrees off the horizon. Jupiter rises 3 hours earlier
still, and will be very bright about 60 degrees above the southeast. Binoculars
or a small telescope will permit you to see the four largest satellites – Io, Europa,
Ganymede, and Callisto – known as the Galilean moons, after their discoverer. They
will clearly shift positions from night to night, an observation which convinced
Galileo that the Copernican world view of a Sun-centered universe was correct. Look
for Mars and Jupiter to rise a bit earlier each night, though their positions relative
to the horizon at dawn will not shift dramatically. By month’s end, Mercury will
join them in the eastern twilight, low enough that it may be difficult to see it
in the horizon clutter and haze.
Saturn is visible in the evening skies, beginning the month to the southwest, about
30 degrees off the horizon. It will move lower as the month advances. Mercury begins
the month in the evening twilight, but is too low to be easily visible, unless you
have a particularly clean view of the western horizon.
Our mid-month overhead view, about 3 hours after sunset, finds Cygnus near zenith,
the Swan is flying along the plane of the Milky Way from north-northeast to south-southwest.
Cygnus lies in the direction of the Sun’s motion around the center of the Milky
Way, a roughly circular orbit which takes between 200 and 250 million years to go
completely around. This is known as the “cosmic year” – and it means that the Sun
and Earth have circled the Galaxy about 18 times since they formed some 4.5 billion
years ago. Deneb is the brightest star in Cygnus. Vega, in the constellation Lyra
lies about 75 degrees above the eastern horizon. Altair, in Aquila, lies about 60
degrees above the southern horizon. These three stars mark the “summer triangle”
– which is high overhead for this summer month.
To the south, closer to the horizon, look for the “teapot” shaped asterism which
marks the constellation Sagittarius. This is the direction toward the center of
the Milky Way. The Galaxy appears brightest and widest here, though the actual center
is obscured by intervening dust and gas clouds. To “see” through them, we observe
at very short (x-ray) or very long (infrared and radio) wavelengths.
If readers have questions about astronomy or science in general that you would like
covered in one of these columns, please feel free to contact me at email@example.com.