We see the sun in the sky almost every day.  Most of us think the sun is a white or yellow orb that shines brightly in the sky, never changing, always the same.  This is not true, however.  The sun has massive eruptions, huge flares and spots that may be several times the size of the Earth.

     One of the easiest things to see on the sun is sunspots.  Sunspots are sites of magnetic flux on the sun.  In these areas, loops of magnetism connect pairs of sunspots, one sunspot being magnetically negative and the other being magnetically positive.  Sunspots vary in size from about 10 miles across up to 100,000 miles across (almost 15 times the diameter of the earth).  Sunspots may last anywhere from a few days for the smaller spots to a few months for the larger sunspots.

     The interesting thing about sunspots is that they appear to be dark when you observe them through a telescope, but if you could pull them off the sun and set them in space by themselves, they would appear very bright.  They appear dark because the rest of the sun is so bright.  Sunspots are approximately 3,000 degrees Fahrenheit cooler than the surrounding solar surface.  The strong magnetic flux associated with the sunspots blocks convection under the spot and the sun’s heat is partially blocked.   

     Every 11 years the number of sunspots increases and decreases. The point at which the number of sunspots visible on the sun is the highest is called sunspot maximum.  The low point of the 11 year cycle is call sunspot minimum.  Sunspot maximum happened in early 2013.  Over the past few years the number of days without sunspots during the year has been increasing. In 2013 and 2015, there were no days without sunspots visible on the sun.  In 2014, there was only one day (0.3%) without sunspots.  In 2016, there were 32 days (9%) without sunspots.  As of November 27, 2017, there have been 87 days (26%) without sunspots. Sunspot minimum is expected to occur in late 2019 or early 2020.

     What does solar minimum mean for the earth?   The most obvious thing will be the reduced chance of seeing northern lights.  Most northern light, but not all, are associated with sunspots and the snapping of their magnetic loops, thus sending material toward the earth.  We may have to wait another three or more years to see a good display of northern lights.

     There is also some evidence that suggests that the Earth may cool a little during sunspot minimums.  For more information about the upcoming solar minimum, go to https://science.nasa.gov/science-news/news-articles/solar-minimum-is-coming

THE NIGHT SKY

The International Space Station is visible as follows:

Evenings–Nov. 25 through Dec. 19.

Mornings–Dec. 25 through Jan. 17.

Evenings–Jan. 24 through Feb. 12.

     For the times of other events, go to www.calsky.com.  You will need to register at this site and load your location to be able to get exact times.  The University of Maine at Presque Isle is located at 68d00m7.8s west longitude and 46d40m45.6s north latitude.

     To get a free sky chart, go to www.skymaps.com.

Sun and Planet Visibility

12/15/2017

07:09 Sunrise.

15:44 Sunset.

Not visible Mercury.

06:48–07:12 Venus.

02:54–06:36 Mars.

03:48–06:54 Jupiter.

Not visible Saturn.

01/15/2018

07:11 Sunrise.

16:11 Sunset.

06:06–07:00 Mercury.

Not visible Venus.

02:36–06:36 Mars.

02:12–07:00 Jupiter.

05:48–06:36 Saturn.

12/09 06:06 Venus 5.0 degrees from Alpha Scorpius (Antares).

12/10 02:51 Last Quarter Moon.

12/12 17:34 ISS passes 0.5 degrees from Alpha Lyra (Vega).

12/12 17:35 ISS passes 1.4 degrees from Alpha Cygnus (Deneb).

12/12 20:48 Mercury at inferior conjunction–between the Earth and the sun.

12/13 02:00 Geminid Meteor Shower–10.7 meteors per hour.

12/13 22:00 Geminid Meteor Shower Peak–39 meteors per hour.

12/14 02:00 Geminid Meteor Shower–48 meteors per hour.

12/15 02:00 Geminid Meteor Shower–7 meteors per hour.

12/15 07:00 Mercury 2.2 degrees from Venus.

12/18 01:30 New Moon.

12/18 20:42 Moon at Apogee–Farthest from the Earth.  This is the farthest apogee of the year–248,693 miles.

12/21 16:00 Saturn in conjunction with the sun.  Farthest from the Earth.

12/25 12:07 Venus 1.1 degrees from Saturn.

12/26 04:20 First Quarter Moon.

12/28 05:14 ISS passes 0.4 degrees from Jupiter.

12/29 05:58 ISS passes 0.6 degrees from Alpha Bootes (Arcturus).

01/01 06:32 ISS passes 1.5 degrees from Beta Gemini (Pollux).

01/01 06:32 ISS passes 0.3 degrees from Alpha Gemini (Caster).

01/01 15:00 Mercury at greatest western elongation (22.7 degrees)–visible in the morning sky.

01/01 16:55 Moon at Perigee–Closest to the Earth–217,599 miles.  This is the nearest perigee of 2018.

01/01 21:24 Full Moon–This is the biggest super moon of 2018.

01/03 06:00 Quadrantid Meteor Shower–14 meteors per hour.

01/03 15:00 Quadrantid Meteor Shower Maximum–60 meteors per hour.

01/04 06:00 Quadrantid Meteor Shower–6 meteors per hour.

01/05 06:18 ISS passes 0.6 degrees from Alpha Cygnus (Deneb).

01/06 19:27 Mars 0.2 degrees from Jupiter.

01/08 17:25 Last Quarter Moon.

01/09 02:00 Venus in Superior Conjunction–other side of the sun.

01/10 05:08 ISS passes 0.8 degrees from Alpha Lyra (Vega).

01/13 00:45 Mercury 0.6 degrees from Saturn.

01/13 05:42 ISS passes 0.2 degrees from Alpha Leo (Regulas).

01/14 21:23 Moon at Apogee–Farthest from the Earth–252,556 miles.

01/16 21:17 New Moon.

01/24 17:20 First Quarter Moon.

01/25 06:18 Mercury at Aphelion–Farthest from the sun.

01/27 18:07 ISS passes 0.4 degrees from the moon.

01/30 05:04 Moon at Perigee–Closest to the earth–223,074 miles.

01/31 06:48 Partial Lunar Eclipse begins.

01/31 06:59 Partial Lunar Eclipse at Moonset.

01/31 08:26 Full Moon.

02/01 18:31 ISS passes 1.4 degrees from Alpha Cygnus (Deneb).