Casual Astronomy, Spaceflight News and Lower California Weather

Mercury & Uranus Now Visible  (see top of blog entry and comments 101 & 157)

By: LowerCal, 8:36 PM GMT on August 20, 2010

CURRENT MOON

moon phases

CURRENT PLANETS
• Very bright & golden Mercury very low east at dawn below bright & blueish star Regulus
• Brilliant white Venus SW after sunset, sets WSW mid-evening
• Bright & reddish Mars low WSW at dusk near bright & blueish star Spica, sets WSW mid-evening
• Brilliant off-white Jupiter low east at dusk with dim (use binoculars) blueish-green Uranus just above, low WSW at dawn (with Uranus just to the right)
• Brilliant & blueish star Sirius rises ESE early morning, SE at dawn

(Directions and times are for the northern subtropics and vary somewhat for other latitudes.)


Scroll past the links below to find special events for current and future dates.
Scroll farther to find past events.


***** Links *****

Today - SpaceWeather.com
also EarthSky,
365 Days of Astronomy
& Bad Astronomy | Discover Magazine
This Week - SkyandTelescope.com - This Week's Sky at a Glance
also Jack Horkheimer - Star Gazer, Current Scripts
& This Week In Space on YouTube
This Month - SkyandTelescope.com - Sky Tour Podcasts
also HubbleSite - Tonight's Sky: Your guide to constellations, deep sky objects, planets, and events
Anytime - Stellarium (free planetarium for your computer)
also Sky & Telescope Interactive Sky Chart (online planetarium)

Visible Satellites:
Simplest - Satellite Flybys by SpaceweatherPhone.com
More satellites and more info - Heavens-Above.com.

Launches:
Spaceflight Now - Worldwide Launch Schedule,
Vandenberg AFB Launch Schedule &
Wallops Flight Facility Launch Webcast & Blog
Reentries - Center for Orbital and Reentry Debris Studies - Upcoming & Recent Reentries

Live Aurora Cams:
Kiruna, Sweden &
Sodankyla, Finland


Most events described below can be viewed with your eyes alone.
Occasionally simple binoculars will improve the view and that will be noted.


***** Current & Future Events *****

Lunar Apogee (Greek apo, away from + Greek Gaia, Earth)

Image credit: Pearson Scott Foresman

Exact at
September 21
0804 GMT
4:04am EDT
1:04am PDT.

The Moon is at its farthest distance in its non circular orbit around Earth. The Moon is about 12% farther than at its closest distance (perigee - Greek peri, near + Greek Gaia, Earth) and the Moon's gravitational influence on Earth and its oceans is about 20% less (due to the inverse square law).


Moon Rides with Jupiter and Uranus

September 22
This night the Moon will travel with the brilliant off-white planet Jupiter. The dim blueish-green planet Uranus is currently positioned about 1° from Jupiter and is visible in binoculars. (See comment 157.)


Equinox Day

Image credit: Przemyslaw "Blueshade" Idzkiewicz & NASA

The September equinox occurs
September 23 at exactly
0309 GMT
September 22 at exactly
11:09pm EDT
8:09pm PDT.

At that moment the Sun will pass directly over the Equator on its way to the Southern Hemisphere. Everywhere on Earth the Sun rises directly east and sets directly west, the length of days will be equal, the length of nights will be equal and the length of day will nearly equal (Latin equi-) night (Latin -noct).

After this date nights will be longer than days in the Northern Hemisphere and vice versa in the Southern Hemisphere. It marks the beginning of autumn for the Northern Hemisphere and the beginning of spring in Southern Hemisphere

How to Balance an Egg on End (On Any Day)

Satellite Outages

One effect of equinoctial periods is the temporary disruption of communications satellites. For all geostationary satellites, there are a few days near the equinox when the sun goes directly behind the satellite relative to Earth (ie, within the beamwidth of the groundstation antenna) for a short period each day. The Sun's immense power and broad radiation spectrum overload the Earth station's reception circuits with noise and, depending on antenna size and other factors, temporarily disrupt or degrade the circuit. The duration of those effects varies but can range from a few minutes to an hour. (For a given frequency band, a larger antenna has a narrower beamwidth, hence experience shorter duration "Sun outage" windows).
Cultural Aspects of the Equinox


Harvest Moon

Image credit: Sky & Telescope

September 23 & Several Following Evenings
The Harvest Moon is the full Moon nearest to the date of the September equinox. This year the full moon follows the equinox by a little over one day (see the previous and next events).

From Hunter's moon - Wikipedia, the free encyclopedia:
In general, the moon rises about 50 minutes later each day, as it moves in orbit around Earth. All full moons rise around the time of sunset. The Harvest Moon and Hunter's Moon are special because—as seen from the northern hemisphere—the time of moonrise on successive evenings is shorter than usual. The moon rises approximately 30 minutes later, from one night to the next, as seen from about 40 degrees N. latitude, for several evenings around the full Hunter's or Harvest Moons.

Thus there is no long period of darkness between sunset and moonrise, around the time of these full moons. In times past, this feature of these autumn moons was said to help hunters tracking their prey (or, in the case of the Harvest Moon, farmers working in the fields). They could continue tracking their prey (or bringing in their crops) by moonlight even when the sun had gone down. Hence the name Hunter's (or Harvest) Moon.

The reason for the shorter-than-usual rising time between successive moonrises around the time of the Harvest and Hunter's Moon is that the orbit of the Moon makes a narrow angle with respect to the horizon in the evening in autumn, leading the Moon to higher positions in the sky each successive day.

○ Full Moon

WunderPhoto: Moonrise over Washington, D.C. by mcqdc Wednesday August 25, 2010

Exact at
September 23
0917 GMT
5:17am EST
2:17am PST.

Rises near sunset and sets near sunrise. At those times the Moon may seem huge (the Moon illusion) and unusually colored. The yellow/orange/red appearance of the Moon at the horizon is at least partly for the same reason the sky appears blue!




Image from: Australian Cooperative Research Centre for Renewable Energy

The gravitational pull of the Moon accounts for about 2/3 of the influence on Earth's tides with the Sun accounting for the remaining 1/3. On this date the gravitational pull of the Moon and Sun are aligned resulting in stronger tides - higher highs, lower lows and faster flows. (Due to the huge mass and volume of the ocean's water the tidal effect lags behind the phases of the Moon. The delay can be as long as three days at some times and places.)

Also see The Moon And Tides.


Return from ISS (International Space Station) of Expedition 24


Mission: ISS Expedition 24
Spacecraft: Soyuz TMA-18

Undocking
September 24
5:34am MSD (Moscow Summer Time)
0134 GMT
September 23
9:34pm EDT
6:34pm PDT.

Deorbit
September 24
8:03am MSD (Moscow Summer Time)
0403 GMT
12:03am EDT
September 23
9:03pm PDT.

Landing
September 24
9:56am AQTT (Aqtobe Time, local time)
0456 GMT
12:56am EDT
September 23
9:56pm PDT.

The last three crew members of ISS Expedition 24 will return to Earth.

There will be live coverage on NASA TV. Check the NASA TV Schedule for times.


Events earlier than those listed below will be found in previous blog entries.

***** Past Events *****

Venus Passes Mars

Image created with Stellarium, a free download.

August 17-19, after Dusk
These evenings above the western horizon the brilliant white planet Venus passes close under the bright and reddish planet Mars. To the lower right is the bright and yellowish planet Saturn. To the upper left is the bright and blueish star Spica.


○ Full Moon

WunderPhoto: Full Moon Last Night by ralfo Sunday July 25, 2010

Exact at
August 24
1705 GMT
1:05pm EST
10:05am PST.

Rises near sunset and sets near sunrise. At those times the Moon may seem huge (the Moon illusion) and unusually colored. The yellow/orange/red appearance of the Moon at the horizon is at least partly for the same reason the sky appears blue!




Image from: Australian Cooperative Research Centre for Renewable Energy

The gravitational pull of the Moon accounts for about 2/3 of the influence on Earth's tides with the Sun accounting for the remaining 1/3. On this date the gravitational pull of the Moon and Sun are aligned resulting in stronger tides - higher highs, lower lows and faster flows. (Due to the huge mass and volume of the ocean's water the tidal effect lags behind the phases of the Moon. The delay can be as long as three days at some times and places.)

Also see The Moon And Tides.


Lunar Apogee (Greek apo, away from + Greek Gaia, Earth)

Image credit: Pearson Scott Foresman

Exact at
August 25
0552 GMT
1:52am EDT
August 24
10:52pm PDT.

The Moon is at its farthest distance in its non circular orbit around Earth. The Moon is about 12% farther than at its closest distance (perigee - Greek peri, near + Greek Gaia, Earth) and the Moon's gravitational influence on Earth and its oceans is about 20% less (due to the inverse square law).


Moon Rides with Jupiter

August 27, Mid Evening through Dawn
These mornnings the Moon will travel with the brilliant off-white planet Jupiter.


Venus Passes Spica

August 30-31, after Dusk
Low in the west as the sky is growing dark the brilliant white planet Venus passes below the twinkling, bright and blueish star Spica.


Moon Passes (Over) the Seven Sisters

September 1, Early Morning
This morning the Moon will pass near the Pleiades star cluster (The Seven Sisters). Six or seven of the stars in this cluster can be seen with the naked eye. Many more can be seen through simple binoculars.

For parts of the southwestern Indian Ocean the Moon will pass over some of the stars in the Pleiades cluster.

Maps and time tables for the disappearance & reappearance of the brightest stars at some cities can be found here with a DATE-TIME of "31 Aug 10". The star names can be found in the chart below.


Image credit: NASA, ESA and AURA/Caltech


◑ Last (or Third) Quarter Moon

Exact at
September 1
1722 GMT
1:22pm EDT
10:22am PDT.

Rises near midnight and sets near noon. Morning crescent moons for a week after. Each one thinner and closer to the eastern horizon.




Image from: Australian Cooperative Research Centre for Renewable Energy

The gravitational pull of the Moon accounts for about 2/3 of the influence on Earth's tides with the Sun accounting for the remaining 1/3. On this date the gravitational pull of the Moon and Sun are at right angles resulting in weaker tides - lower highs, higher lows and slower flows. (Due to the huge mass and volume of the ocean's water the tidal effect lags behind the phases of the Moon. The delay can be as long as three days at some times and places.)

Also see The Moon And Tides.


Mars Passes Spica

September 5-6, after Dusk
Low in the west as the sky is growing dark the bright and reddish planet Mars passes above the twinkling, bright and blueish star Spica.


Lunar Perigee (Greek peri, near + Greek Gaia, Earth)

Image credit: Pearson Scott Foresman

Exact at
September 8
0402 GMT
12:02am EDT
September 7
9:02m PDT.

The Moon is at its closest distance in its non circular orbit around Earth. The Moon is about 10.5% closer than at its farthest distance (apogee - Greek apo, away from + Greek Gaia, Earth) and the Moon's gravitational influence on Earth and its oceans is about 25% greater (due to the inverse square law).

(Perigean Tides - The tidal enhancement of this perigee precedes by a mere 6 hours the peak of tidal forces due to the dark moon [astronomical new moon] - see the following event. The combined tidal force is the 2nd strongest of this year.)


Dark Moon (a.k.a. astronomical new moon)

Exact at
September 8
1030 GMT
6:30am EDT
3:30am PDT.

Lower and thinner morning crescent moons the week before. Higher and thicker evening crescent moons the week after.




Image from: Australian Cooperative Research Centre for Renewable Energy

The gravitational pull of the Moon accounts for about 2/3 of the influence on Earth's tides with the Sun accounting for the remaining 1/3. On this date the gravitational pull of the Moon and Sun are aligned resulting in stronger tides - higher highs, lower lows and faster flows. (Due to the huge mass and volume of the ocean's water the tidal effect lags behind the phases of the Moon. The delay can be as long as three days at some times and places.)

Also see The Moon And Tides.


) Thinnest Evening Crescent Moon (the original meaning of "new moon")

WunderPhoto: Brand New Moon by Ohlen Wednesday June 4, 2008

September 8, 9 or 10
Low in the western sky soon after sunset.

Earliest and thinnest sightings of the new moon may be possible from the central and western South Pacific September 8. Progressively easier sightings will be possible from New Zealand, Australia, Southeast Asia, India, the Arabian Peninsula, Africa, South America and southern North America September 9. Sighting from almost all of the rest of the world will be possible September 10.

See the visibility maps at Moonsighting.com.


Photo Ops: Crescent, Venus, Mars & Spica

September 10, 40 Minutes after Sunset


September 11, 40 Minutes after Sunset

Images created with Stellarium, a free download.

These evenings four celestial objects appear in close proximity low above the WSW horizon: a thin crescent moon, the brilliant white planet Venus, the bright and reddish planet Mars and the twinkling, bright and blueish star Spica.


Resupply Mission to the International Space Station (ISS) + Double Spacecraft Flyovers

Image credit: NASA

Mission: Flight 39P to ISS (cargo/resupply)
Spacecraft: Progress M-07M
Launch Vehicle: Soyuz-U
Launch from Baikonur Cosmodrome, Kazakhstan
September 8
4:11pm AQTT (Aqtobe Time, local time)
1111 GMT
7:11am EDT
4:11am PDT.

September 10
3:22pm AQTT (Aqtobe Time, local time)
1022 GMT
6:22am EDT
3:22am PDT.

Docking with ISS
September 10
4:40pm MSD (Moscow Summer Time)
1240 GMT
8:40am EDT
5:40am PDT.

September 12
3:58pm MSD (Moscow Summer Time)
1158 GMT
7:58am EDT
4:58am PDT.

Launch status updates at
Spaceflight Now | Tracking Station | Worldwide launch schedule.

Live coverage of the docking will be on NASA TV - see the NASA TV Schedule.


WunderPhoto: Endeavour and the ISS by WeatheringHeights Tuesday March 25, 2008

Between launch and docking with the ISS it may be possible to sight both craft in the sky at the same time.

Check satellite pass predictions at
Heavens-Above
or try the simpler tool at
Satellite Flybys by SpaceweatherPhone.com.


◐ First Quarter Moon

Exact at
September 15
0550 GMT
1:50am EDT
September 14
10:50pm PDT.

Rises near noon and sets near midnight. Evening crescent moons for a week before. Each one thicker and higher above the western horizon.




Image from: Australian Cooperative Research Centre for Renewable Energy

The gravitational pull of the Moon accounts for about 2/3 of the influence on Earth's tides with the Sun accounting for the remaining 1/3. On this date the gravitational pull of the Moon and Sun are at right angles resulting in weaker tides - lower highs, higher lows and slower flows. (Due to the huge mass and volume of the ocean's water the tidal effect lags behind the phases of the Moon. The delay can be as long as three days at some times and places.)

Also see The Moon And Tides.


Vandenberg Minuteman III Launch

Image credit: USAF

Mission: Unarmed ballistic missile test
Target: Near the Kwajalein Atoll
Launch Vehicle: Minuteman III
Launch from Vandenberg AFB, California
September 15
time to be determined (TBD)

September 17
3:01-9:01am PDT (local time)


Vandenberg Atlas V Launch

Photo credit: domain-b.com

Mission: National Reconnaissance Office Launch 41 (NROL-41) - classified
Launch Vehicle: Atlas V 501
Launch from Vandenberg AFB, California
September 20
time to be determined (TBD)

September 21
0329 GMT
September 20
11:29pm EDT
8:29pm PDT (local time).

Launch status updates are at
Spaceflight Now | Tracking Station | Worldwide launch schedule.

More details appear on a launch blog at
Spaceflight Now | Atlas Launch Report | Mission Status Center
as the launch date nears.

You can find more info on the mission at
United Launch Alliance
along with a link to a live webcast that will begin 20 minutes before launch.


web counterVisitor Map
Create your own visitor map!

Updated: 7:20 PM GMT on September 21, 2010

Permalink

About LowerCal

Astronomy with a minimum of terminology and technology.

Local Weather

Scattered Clouds
77 °F
Scattered Clouds

LowerCal's Recent Photos

Personal Weather Stations

APRSWXNET Woodland Hills CA US
Calabasas, CA
Elevation: 984 ft
Temperature: 51.0 °F
Dew Point: 34.0 °F
Humidity: 53%
Wind: Calm
Wind Gust: 2.0 mph
Updated: 5:33 AM PST on December 01, 2013
At Gonzales Drive
Woodland Hills, CA
Elevation: 984 ft
Temperature: 74.4 °F
Dew Point: 39.2 °F
Humidity: 28%
Wind: Calm
Wind Gust: 1.0 mph
Updated: 10:59 AM PDT on October 25, 2014

About Personal Weather Stations