Category Archives: sky

If you haven’t seen Jupiter and Saturn, you’re missing something! | Astronomy Essentials | EarthSky

A *deep* dive into what’s happening RIGHT NOW. Look up more than one night. 

[snip] The 2020 great conjunction of Jupiter and Saturn will be the closest since 1623 and the closest observable since 1226! On December 21, Jupiter and Saturn will be only 0.1 degree apart. [“Then the two largest worlds in the Solar System will appear in Earth’s sky separated by only about 1/5 the apparent diameter of a Full Moon.”] Some say the pair will look like an “elongated star” on that date. Will they? Or will they look like a double planet? To know for sure, we’ll have to look and see. They’ll surely be an appealing and mind-expanding sight.

2002’s extra-close Jupiter-Saturn conjunction won’t be matched again until the Jupiter-Saturn conjunction of March 15, 2080.

Equinox, more or less

The Sky This Week, 2020 September 15 – 22 — Naval Oceanography Portal

The astronomical season of autumn begins on the 22nd at 9:31 am EDT.  This is the moment when the Sun’s disc reaches an ecliptic longitude of 180 degrees and crosses from the northern hemisphere of the sky into the southern hemisphere.  While the term “equinox” means “equal night”, a glance at a sunrise/sunset table reveals that the difference between sunrise and sunset on this date isn’t exactly 12 hours as one might expect.  Since the Sun subtends a tangible disc and we measure sunrise and sunset by the first and last appearances of the solar limbs, the duration of daylight is 12 hours and 8 minutes on the 22nd here in Washington.  The actual date when day and night are equal falls on the 26th.  From then until March 16th next year our nights will be longer than our days.

[“Hello, darkness, my old friend.”]

Latest sunset 6/27/20

The Sky This Week, 2020 June 23 – 30 — Naval Oceanography Portal

The year’s latest sunset occurs on the 27th for folks living in northern temperate latitudes.  Here in Washington Old Sol slips below the horizon at 8:38 pm EDT that evening.  Most of us probably won’t notice the Sun’s gradual return to earlier set times for a couple of weeks; he won’t set before 8:30 pm until July 20th.  On the other end of the day, though, sunrise is now four minutes later than it was on June 13th, so the days are indeed beginning to gradually get shorter.

Summer Solstice — Winter is coming

The Sky This Week, 2020 June 16 – 23 — Naval Oceanography Portal

Astronomical summer officially arrives on the 20th at 5:44 pm EDT.  This is the moment when Old Sol reaches an ecliptic longitude of 90 degrees, and it also happens to be the time when he reaches his highest northern declination, with the center of his disc perched over the Tropic of Cancer.  This is the longest day for residents of the Northern Hemisphere, but the length of day varies widely with latitude.  Here in Washington we will have 14 hours 54 minutes between sunrise and sunset.  Residents of Hawai’i will only see 13 hours 20 minutes of daylight, while residents of Fairbanks will have 21 hours and 50 minutes to enjoy the Sun along with twilight to fill the remaining hours.

Happy Equinox!

The Sky This Week, 2020 March 17 – 24 — Naval Oceanography Portal

The vernal equinox occurs on the 19th at 11:50 pm EDT.  This moment marks the instant when the ecliptic longitude of the Sun reaches zero degrees and begins another circuit around the sky.  This is the earliest occurrence of the equinox since the year 1896, and we will continue to see equinoxes on the 19th (in EDT) every four years through the year 2096.

[T]he actual day of “equilux” occurred on March 16th.  From now until the next “equilux” day on September 25th we will have more daylight than darkness.

Earliest sunsets through 12/12 (also the Full Moon)

The Sky This Week, 2019 December 3 – 10 — Naval Oceanography Portal

This week we begin to see the phenomena associated with the winter solstice.  The solstice “season” begins with the year’s earliest sunsets, which occur all of this week.  Here in Washington the Sun disappears below the horizon at 4:46 pm EST.  He will gradually start to set later starting on December 13th.  Although this gives the illusion of the days getting longer, we won’t see our latest sunrise until early January.  In between the solstice occurs on the 21st, which will be the year’s shortest day.  This seemingly odd behavior is due to the way we now keep time.

December’s Full Moon is variously known as the Long Night Moon, Old Moon, or the Moon Before Yule.  Since this Full Moon occurs closest to the winter solstice is will be the most northerly one of the year, beaming down on the frosty landscape below. 

Cold Moon is full 12/13/16

The Sky This Week, 2016 December 6 – 13

The Moon brightens the evening sky this week, waxing toward the Full phase as she courses through the late autumn and early winter constellations. Full Moon occurs on the 13th at 7:06 pm Eastern Standard Time. December’s Full Moon is known as the Moon Before Yule in the skylore of European Christianity. Other names, such as the Cold Moon, Big Moon, and Long Night Moon, reflect the influence of Celtic and Native American lore. December’s Full Moon occurs near Luna’s most northerly declination for the year, flooding the winter landscape with her pale light. This year she appears a bit brighter than usual thanks to the Full phase occurring near the Moon’s close perigee, which falls on the 12th. On the evening of the 12th you’ll find the nearly-full Moon pass through the heart of the Hyades star cluster which forms the “face” of Tauris, the Bull. Watch Luna creep closer to the bright star Aldebaran as the evening passes. At 11:07 pm EST the star will wink out as the Moon’s limb covers it. You can see it re-appear at 12:21 am.

The Full Moon washes out the annual Geminid meteor shower, which peaks on the night of the 13th. This is normally one of the year’s most reliable showers, and under dark skies it usually produces one or two “shooting stars” per minute. The meteors are generally slower than the August Perseids, and the radiant, in the constellation of Gemini, is well-placed after around 10:00 pm. Bright moonlight will hamper the number of meteors that the average observer will see this year, but a patient observer may be able to spot 20 or so per hour, even from urban locations.

2016 Ends with Three Supermoons – NASA

2016 Ends with Three Supermoons

Since the moon’s orbit is elliptical, one side (perigee) is about 30,000 miles closer to Earth than the other (apogee). The word syzygy, in addition to being useful in word games, is the scientific name for when the Earth, sun, and moon line up as the moon orbits Earth. When perigee-syzygy of the Earth-moon-sun system occurs and the moon is on the opposite side of the Earth from the sun, we get a perigee moon or more commonly, a supermoon!

This coincidence happens three times in 2016. On October 16 and December 14, the moon becomes full on the same day as perigee. On November 14, it becomes full within about two hours of perigee—arguably making it an extra-super moon.

The full moon of November 14 is not only the closest full moon of 2016 but also the closest full moon to date in the 21st century. The full moon won’t come this close to Earth again until November 25, 2034.

The Hunter’s Moon, 10/15-16

The Sky This Week, 2016 October 11 – 18

Full Moon occurs on the 16th at 12:23 am Eastern Daylight Time. October’s Full Moon is popularly known as the Hunter’s Moon. The geometry of the Moon’s path in the sky is similar to last month’s Harvest Moon, so the interval between successive moonrises around the time of Full Moon causes Luna to appear to rise at nearly the same time for a few nights. In September this phenomena was used by farmers to use the light of the rising Moon to help them bring in more crops. This month hunters have a bit of extra light to pursue game across the stubble of the harvested fields.

Thunder Moon, 7/19

Full Moon occurs on the 19th at 6:57 pm Eastern Daylight Time. July’s Full Moon is popularly known as the Hay Moon, Buck Moon, or Thunder Moon, with the latter being particularly appropriate for this time of the year.

from The Sky This Week