February 2013 Night Sky Calendar
They call it the "February consolation." (No, we have no idea who 'they' are, either.) The February consolation consists of the subtle light we can now see at 5:00 p.m. or the hint of heat one feels when extending a palm toward the Sun: indications that the winter is aging and the spring is imminent. The Sun ascends gradually, but inexorably, toward its solstice peak. The lucky many who don't live two ticks atop Terra Incognita can expect the thaw within a few weeks. The rest of us will continue to savor the lingering winter like a slowly decanted brandy until the time we commemorate our nation's violent break from the Kingdom.
And though we see and feel the hints of impending warmth, February is still deep winter: the core of the cold, of course, but also the time when the winter night is ablaze with starlight. The winter sky wall is front and center by early evening: the Milky Way thoroughfare traverses the heavens from horizon to horizon. Though we'll focus on these star things from time to time this time, today's crux is on the celestial objects that appear to move amongst them: namely, planets, the Moons, meteors and the like.
This month we don't have quite as many highlight sights as usual. (This calendar includes events we deem "noteworthy," an example of our smugness and arrogance. Now another astronomer might tell you that one can see a hundred noteworthy events every single night. However, we have to be practical: so we'll pick and choose from the abundance.)
Because we're experiencing a lull, we promise to be as long-winded as possible so we can inflate this article with plenty of down and flannel.
SUNDAY, FEBRUARY 3:
LAST QUARTER MOON 3.5 DEGREES SSW OF SATURN
Three cheers for space efficiency. We combined two events into one sentence. On Super Bowl Sunday you'll see the Ring Lord world less than a hand's width "above" the last quarter moon. Right now, Saturn is the third brightest planet after Jupiter and Mercury. (Venus is backstage screaming at her agent until mid Spring.) So, having the Moon nearby helps us identify this moderately bright planet. Saturn and its lunar companion rise tonight around 12:30 a.m.
TUESDAY, FEBRUARY 5:
MOON 6.2 DEGREES NORTH OF ANTARES
Now, this event is a comfort for hot weather lovers. The crescent moon is close to Antares, the brightest star within Scorpius the Scorpion. Scorpius and its eastern companion Sagittarius are the famous summer patterns. Find the Moon north of the Scorpion's heart in the post midnight eastern sky.
FRIDAY, FEBRUARY 8:
MERCURY 0.27 DEGREES NNW OF MARS
This is about the last time you can see Mars and the first time you can see Mercury this month. Mercury is the brighter of the two. See both planets very low in the western evening sky.
SUNDAY, FEBRUARY 10:
Beginning of lunation cycle 1115
MONDAY, FEBRUARY 11:
MOON 5.0 DEGREES NNW OF MERCURY
A splendid opportunity to find the elusive little planet. Mercury has just arrived on the scene and the Moon is merely a day old: the thinnest of slivers next to the first world. See them both very soon after sunset in the western evening sky.
SATURDAY, FEBRUARY 16:
SUN ENTERS AQUARIUS
The Sun APPEARS to enter Aquarius constellation. This apparent "entrance" is a consequence of Earth's orbital motion: as we revolve around the Sun, the Sun's position relative to the background stars changes. Our parent star seems to travel through thirteen different constellations each year: a stellar retinue called "The Zodiac." This parade consists of Aries the Ram; Taurus the Bull; Gemini the Twins; Cancer the Crab; Leo the Lion; Virgo the Maiden; Libra the Scales; Scorpious the Scorpion; Ophiuchus the Serpent Charmer; Sagittarius the Archer; Capricornus the Seagoat and AQUARIUS THE WATER BEARER.
SATURDAY, FEBRUARY 16:
MERCURY AT GREATEST EASTERN ELONGATION
Even by Mercury's standards, it is a hyper kinetic little thing this month. The first world leaps up into view mid month and reaches its greatest western elongation point today. It will be 18.1 degrees from the Sun. When at greatest eastern elongation, Mercury will be up in the western evening sky.
SATURDAY, FEBRUARY 16:
MERCURY AT PERIHELION
Of course! A whole week of nothing followed by three events on a Saturday. "Perihelion" is the closest point in a planet's orbit. We remember that a planet moves fastest when it is close to its parent star: so, when Mercury reaches its greatest elongation, it will be at its swiftest. This coincidence of greatest elongation with perihelion explains why Mercury's descent back toward the setting Sun will be so rapid. Mercury will still be about 28 million miles from the Sun today.
SUNDAY, FEBRUARY 17:
FIRST QUARTER MOON
MONDAY, FEBRUARY 18:
MOON 0.90 DEGREES SOUTH OF JUPITER (PICK EVENT)
We really are Jovian sycophants this months, aren't we? Jupiter is the pick planet and its close approach to the Moon is the pick event. The 'pick event' is the 'must see' one of the month. If you devote anytime at all to astronomy in February, venture out on February 18th to see the Moon and waxing gibbous moon together in the sky.
TUESDAY, FEBRUARY 19:
Planets never stop! They only appear to at certain times. When a planet halts its progression either eastward (prograde) or westward (retrograde), before reversing course, we say it is stationary. We're seeing an illusion: as our faster moving Earth approaches and then passes a slower superior planet, such as Saturn, we see it stop and reverse course relative to the background stars. The sixth world's retrograde motion precedes its opposition: when Earth passes directly between it and the Sun. This opposition occurs on April 28th.
THURSDAY, FEBRUARY 21
VENUS AT APHELION
"Perihelion" is the closest point in a planet's orbit; "Aphelion" is the most distant. Venus reaches it aphelion point today and will be nearly 67 million miles from the Sun. Venus orbits more slowly than usual, but still much faster than the Sun. Since we can't see Venus at all, this event is purely academic.
FRIDAY, FEBRUARY 22
As mentioned in the Feb 19th entry, planets never stop! All planets appear to change directions. This apparent reversal for a superior planet occurs when our planet catches up with it. An inferior planet's direction changes from our perspective because we're on the outside of its orbit: just as spectators watching the Grand Prix will see cars move in one direction and then the other as they race around the track, we can see Mercury and Venus alter their courses during each orbit.
SATURDAY, FEBRUARY 23
MOON 6.2 DEGREES SSW OF THE BEEHIVE STAR CLUSTER
The Beehive Star Cluster, also known as Praesepe, is Cancer the Crab's one prominent feature: a glowing thumb smudge on the obscure crab's fess point. This stellar gathering comprises the "beehive" that the ravenous Leo the Lion hungrily pursues. Tonight, the nearly full moon lingers within a hand's width of the bees.
MONDAY, FEBRUARY 25
The hunger moon or the snow moon: the moon that looms above a frigid, barren landscape. As the February full moon occurs so late in the month, it is also the moon that slowly usher winter out: to make way for the eventual equinox and life's resurgence.
MERCURY: At first it is gone; then Mercury comes on stage for a tap and a dance and then bolts again as though thinking the crowd is too stern for its liking. One won't see Mercury at month's beginning, but then it pole vaults (to mix metaphors) up into the evening sky, around the same time that Mars takes it leave. It's as though the exasperated Mars rushes behind the curtain, says "This pack is too vicious; you have a go." and then Mercury hops high into the sky. Mercury is at greatest eastern elongation on Feb 16th and then rapidly exits and won't be visible at month's end. VERDICT: This one is simple: see Mercury in the mid month when it will climb high in the western evening sky. Don't bother looking at month's beginning and end.
VENUS: Not visible this month. Our sister world sulks until late May. VERDICT: Well, there's not much left to say. It is interesting to note that last year at this time we were already giddy about the June Venusian transit. One might remember that Venus took 2-pi's worth of the spotlight the first half of 2012. Now, Venus is beyond our vision until the University's summer session begins.
MARS: Mars remains visible very low in the western evening sky during February's first days. Then, it will accompany Venus in the shadows: but returns to our sky in June! VERDICT: If you feel as thought you MUST see Mars before its protracted hiatus, find a unobstructed western horizon and seek it in twilight the first week of February. After that, you'll have to await its early summer return.
JUPITER (PICK PLANET) Yes, we know that Jupiter has donned the diadem for quite a while now. However, this month is doesn't have much competition. Venus is gone. Mars is soon to follow. Mercury appears then vanishes; and Saturn is up after midnight. Jupiter is prominent in the evening and, in Venus' absence, is the brightest of them all. Saturn will get the coveted crown soon, but for now Jupiter retains its reign as the pick planet.
SATURN: To continue this thespian theme, Saturn is the last act after the obscure Mars, jumping Mercury and glory hog Jupiter. Saturn rises after midnight and ascends in the eastern post-midnight sky. Saturn will gain greater prominence as we move into the spring and summer. VERDICT: the planet for late night observers, Saturn will grow brighter throughout the next few months. Currently, it is only brighter than Mars this month.
PLANETS IN ORDER OF BRIGHTNESS (from brightest to dimmest)
JUPITER - MERCURY - SATURN - MARS
February 2013 Night Sky Calendar