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February Skies


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February Skies

by Dick Cookman

01/30/2014

Highlights: Comet Journal, Martian Landers, Meteor Showers, Planet Plotting, February Moon

Focus Constellations: Ursa Major, Ursa Minor, Draco, Cepheus, Cassiopeia, Camelopardalis, Lynx, Leo, Cancer, Gemini, Auriga, Taurus, Perseus

Comet Journal

Comet C/2012 X1 ( LINEAR ) and Comet C/2013 R1 (Lovejoy) are the brightest comets of February. They are morning comets and both are visible in 50 mm binoculars at 8th magnitude and can be found in Serpens Cauda.

Comet Lovejoy passed through perihelion in December and is currently decreasing in brightness as it retreats to the Oort Belt. Comet Linear will remain at 8th magnitude as it approaches perihelion on the 21st above the June part of Earth's orbit. It will be closest to Earth on June 27th after dropping through the plane of the solar system between Earth and Mars.

Mars Landers

Mars arrives at its Summer Solstice for the northern hemisphere on February 15th. On January 2nd the planet was most distant from the Sun at aphelion so this is a particularly cool summer. However, both rovers are in the southern hemisphere and are experiencing a particularly cold winter due to the distance of the Sun. The planet receives 45% more energy when at perihelion than when it is at aphelion so the rovers can break out their bikinis for an exceptionally warm southern hemisphere summer solstice on Jan. 11, 2015.

Opportunity is on Solander Point. The Mars Odyssey orbiter which went into safe mode on Sol 3509 (Dec. 7, 2013) and interrupted relay support for Opportunity resumed relay service on Sol 3514 (Dec. 12, 2013). Prior to resumption, Opportunity contacted Earth on Sol 3512 (Dec. 10, 2013) and indicated it was ok. The rover was instructed to conduct a drive on Sol 3512. Opportunity drove about 22 feet (6.6 meters) to reach some targets for examination over the Christmas holidays. The previously elevated right-front wheel current had settled down to more typical levels possibly because the actuator was rested and the rover position changed. The rover is on the edge of an exposed outcrop where orbital observations suggest possible presence of small amounts of clay minerals. The rover has been finishing up analysis of the Cape Darby area before moving on toward what the team believes will be the best winter location. As of Sol 3540 (Jan. 7, 2014), the solar array energy production improved to 360 watt-hours.

“We’re looking at the legacy of Opportunity’s first decade this week, but there’s more good stuff ahead,” said Steve Squyres of Cornell University, Ithaca, N.Y., the mission’s principal investigator. “We are examining a rock right in front of the rover that is unlike anything we’ve seen before. Mars keeps surprising us, just like in the very first week of the mission.”

Some may wonder what Curiosity is doing on Mars now that the mission objective has been achieved. The Science Laboratory was sent to Mars to find evidence of present or past habitable environments. The rocks examined in Crater provide that evidence in that they are comprised of substances deposited in the clays representing rather benign conditions in a low salinity, moderate pH, relatively warm lake environment.

The new mission has a twofold objective. One is to determine the geographic extent and geologic time duration of this environment and the second is to find Martian substances of organic origin. The mere existence of organic molecules is not sufficient as organic molecules are defined as molecules comprised of combinations of hydrogen, carbon, nitrogen, and phosphorus. Certainly these are the basic elements of life, but they are not limited to living organisms –– and can be found under abiotic conditions. Recent experiments involving bombardment of ices similar to those in comets produced amino acids which are the building blocks of proteins. In fact, amino acids have been recovered from within meteorites which are thought to have formed deep within asteroids or minor planets broken apart by collisions with similar bodies.

Meteor Showers

Since the Alpha and Beta Centaurid Meteor Showers on February 8th radiate from Centaurus at latitude 60°S, most meteors are well below the southern horizon. The Delta and Sigma Leonids on the 23rd and the 26th are minor showers that normally produce fewer than 5 meteors per hour in dark skies. February and March are currently among the poorest months for northern hemisphere observers of meteor shower and sporadic meteors but meteors brighter than Venus may be more frequent. On a typical night of the year, stargazers might see about 10 “sporadic” fireballs, created by fragments of asteroids or comets that burn up in the Earth’s atmosphere. But some studies indicate that the number spikes by 10 to 30 percent during the spring. The fireballs come from the asteroid belt, but their exact source remains unknown.

Planet Plotting

Following solar conjunction in December, Mercury reached greatest western elongation on Jan. 31st and and appears at magnitude -0.6 in Caricornus in the west southwest after sunset. It will reach inferior conjunction on the 15th and move into the morning sky in Aquarius in late February. Jupiter (-2.5) in Gemini passed opposition in early January and still dominates the evening sky. Neptune (+8.0 in Aquarius) disappears into the glare of sunset in early February and reaches solar conjunction on the 23rd. Uranus (+5.9 in Pisces) is still visible with 50mm binoculars in the west in early evening.

Mars rises in Virgo before midnight and brightens by almost 75% in February as it moves toward opposition in April when it makes its closest approach to Earth. It's distance from Earth for this opposition is relatively great because Mars will be just passed aphelion for the April opposition and the aphelion distance for Mars is 20% greater than its perihelion distance. This is in contrast to the 2003 opposition when Mars was close to perihelion and 40% closer to Earth at 56 million kilometers.

Saturn (+0.4 in Libra) rises after midnight and can be best observed in the hour before dawn when it is higher in the south. Venus is the bright morning planet in Sagittarius in the southeastern sky. It is at magnitude -4.8 on the 1st and rises higher and brighter to magnitude -4.9 in midmonth then drops lower in the sky and dims slightly to magnitude -4.8 by the 28th. The thin sliver of a crescent Venus that brightened the morning sky in January is replaced with a much fatter crescent in February accounting for the increase in magnitude.

PlanetConstellationMagnitudePlanet Passages
SunCapricornus, Aquarius-26.8Neptune Conjunction, 2/23, 1:00PM EST
MercuryCapricornus, Aquarius-0.6 to +3.9 to +0.9Inferior Conjunction 2/15, 3PM EST
VenusSagittarius-4.8 to -4.9 to -4.8 
MarsVirgo+0.2 to -0.4 
JupiterGemini-2.6 to -2.4 
SaturnLibra+0.5 to +0.4 
UranusPisces+5.9 
NeptuneAquarius+8.0Solar Conjunction 2/23, 1:00PM EST

February Moon

Lunation 1127 began with the Jan. 30th New Moon. It ends 29.43 days later at New Moon on March 1st. February has no New Moons but January and March each have two. The Full Moon is in Cancer on February 14th at 6:53PM EST.

February's Full Moon was referred to as the "Trapper's Moon" in Colonial America. Celts referred to it as “Moon of Ice” and Chinese call it “Budding Moon." To Medieval English it was the “Storm Moon” and Anishnaabe (Chippewa and Ojibwe) of northern Michigan celebrate it as the “Namebini-giizis” (Sucker Moon).

The Moon is at the farthest point in its orbit, 252,421 miles (63.69 Earth Radii) from Earth at apogee on the 12th at 12:10AM EST. Perigee, where the Moon orbits closest to Earth at a distance of 223,967 miles (57.51 Earth Radii), is on the 27th at 2:51PM EST. Perigee is within 2 days of New Moon producing higher lunar tides from the closer that normal Moon.

Full and New moon occur when the Moon is at the syzygies of its orbit. The syzygies are where the positions of the Earth and Moon line up with the Sun. The elliptical orbit of the Moon rotates around the Earth every 413+ days causing perigee and apogee to move and pass through the syzygies twice in 413+ days. It takes 413.32 days to complete 14 full moon cycles and 413.42 days for 15 perigee cycles. So, perigee and apogee can occur within 12 hours of the full or new moon occur twice within this time period. "Supermoons" are New and Full Moons within 90% of closest approach to Earth according to Richard Nolle. They occur 7.5 lunar months apart, alternating between new and full Moons. Both of the New Moons of January were "Supermoons" with the later one also called a "Black Moon" –– the 2nd New Moon in a month.

The proxigee for 2014 (closest perigee of the year) occurs on the Full Moon of August 10th (55.96 Earth Radii) and the next closest perigee for 2014 occurred on the New Moon of January 1st. There was a closest perigee at Full Moon on June 22, 2013 but the previous closest perigee at New Moon was in 2012.

Life would not exist on Earth without the tidal influence of the Moon which stabilizes the precession (wobbling) of the Earth confining the tilt of the rotational axis to the plane of Earth's orbit to a range between 21.5 and 24.5° in contrast to the extremes allowed by the weak tidal effect of the small moons of Mars. These extremes produce much larger climate variation. Some think that the lunar distance and alignment rhythms may also correlate to rhythms in all fluids (including the oceanic and atmospheric tides, magma motion above mantle hot spots, convection of the low viscosity asthenosphere beneath Earth's tectonic plates, and large scale motion of other fluids). Even the convection in the liquid metal of the outer core which is thought to control Earth's magnetic field and our protective magnetosphere may be affected. Some have observed that extreme weather tends to be in a period 3 days either side of the proxigee moons.

PlanetConstellationMagnitudeMoon PassageMoon Phase/Age
MercurySagittarius-0.64.0°N, 2AM EST, 2/1Waxing Crescent ~ 1.39 days
MercurySagittarius+0.93.0°N, 4PM EST, 2/27Waning Crescent ~ 27.97 days
VenusSagittarius-4.70.4°N, Midnight EST, 2/25Waning Crescent ~ 26.31 days
MarsVirgo-0.13.0°S, 7PM EST, 2/19Waning Gibbous ~ 20.10 days
JupiterGemini-2.55.0°S, 1AM EST, 2/11Waxing Gibbous ~ 11.35 days
SaturnLibra+0.40.3°S, 5PM EST, 2/21Waning Crescent ~ 22.01 days
UranusPisces+5.93.0°N, 6PM EST, 2/3Waxing Crescent ~ 4.06 days
NeptuneAquarius+8.05.0°N, 9AM EST, 2/1Waxing Crescent ~ 1.76 days
NeptuneAquarius+8.05.0°N, 7PM EST, 2/28Waning Crescent ~ 29.10 days




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