By Glenn A. Walsh
Reporting for SpaceWatchtower
At the moment of this blog posting,
Monday Afternoon, 2015 July 6 at 3:41 p.m. Eastern Daylight Saving
Time (EDT) / 19:41 Coordinated Universal Time (UTC), Earth reaches
the farthest point from the Sun for the year 2015, two weeks after
the Summer Solstice. So, although Earth's Northern Hemisphere is now
entering the season of Summer, when we expect the warmest daily
temperatures of the year, this is also the time of year when we are
farthest from the Sun.
Known by the astronomical term,
Aphelion, this is the point in Earth's eliptical orbit of the Sun
when the Sun looks a wee bit smaller due to the greater distance
between the two celestial bodies. Actually, since the Earth reached
its closest point to the Sun on January 4 (known by the astronomical
term, Perihelion), the distance between the Earth and the Sun has
changed by about three and one-half percent.
Although, due to the great brightness
of the Sun, it is very difficult to discern the difference in size of
the Sun from one part of the year to another. AND, anyway, one should
NEVER look directly at the Sun without the proper training and
equipment to do so safely. Otherwise, one could severely damage the
eyes, without any awareness of pain, because there are not nerves in
the eyes.
At Earth's Aphelion, the Earth is now
152,093,480 kiometers / 94,506,507 miles from the Sun. At last year's
Aphelion (which occurred on Independence Day), Earth was just a
little closer to the Sun: 152,093,408 kilometers / 94,506,462 miles.
So, there is a little variability, in this event, in both the date
and the distance, from year-to-year.
The Earth was at its closest point to
the Sun back on January 4, 14 days after the Winter Solstice, when
the Earth was 147,096,204 kilometers / 91,401,343 miles from the Sun.
The average distance between the Earth and the Sun is about 150
kilometers / 93 million miles.
The reason for the annual change in the
distance between the Sun and the Earth is because the Earth's orbit
around the Sun is not quite circular. The orbit is an elipse, with
the Sun not quite exactly in the center of the orbit.
At Perihelion in January, Earth
actually receives about seven percent more solar energy than
received this month at the point of Aphelion. However, our planet's
large oceans, as well as the atmosphere, are very efficient in
storing and more evenly distributing the Sun's heat, so that Earth's
overall temperature from solar heating remains pretty much the same
throughout the year.
It is the inclination of the Earth's axis, relative to its orbit around the Sun, that causes Summer to be much warmer than Winter. During the season of Summer, the Northern Hemisphere receives much more direct sunlight, as at the Summer Solstice the Northern Hemisphere was tilted the full 23 and one-half degrees toward the Sun.
It is the inclination of the Earth's axis, relative to its orbit around the Sun, that causes Summer to be much warmer than Winter. During the season of Summer, the Northern Hemisphere receives much more direct sunlight, as at the Summer Solstice the Northern Hemisphere was tilted the full 23 and one-half degrees toward the Sun.
Due to the fact that the Earth's orbit
around the Sun is an elipse, the Northern Hemisphere actually
benefits by having our Summers last about five and one-half days
longer than our Winters! This is caused by our Earth (or any planet)
moving more rapidly around the Sun when it is closest (at or near
Perihelion), than when it is further away (at or near Aphelion).
In Etymology, the word Aphelion
comes from the Greek word apo (meaning “away, off, apart”)
and the word Helios (Greek God of the Sun).
More on Perihelion and Aphelion:
Link >>> https://en.wikipedia.org/wiki/Perihelion_and_aphelion
More details about today's Aphelion:
Link >>> https://in-the-sky.org/news.php?id=20150706_08_100
Safe Way to View the Sun During a Solar Eclipse or Eclipse of the Sun:
Link >>> http://andrewcarnegie.tripod.com/solflyer2.htm
Related Blog Posts ---
Snowballs on the First Day of Summer!
2015 June 21.
Link >>> http://spacewatchtower.blogspot.com/2015/06/snowballs-on-first-day-of-summer.html
Winter: Sun. 6:03 p.m. EST; Ursid Meteor Shower w/Web-Cast Peaks Mond
2014 Dec. 21.
Link >>> http://spacewatchtower.blogspot.com/2014/12/winter-solstice-winter-begins-sun-603.html
Summer Begins Saturday Morning at 6:51 a.m. EDT.
2014 June 19.
Link >>> http://spacewatchtower.blogspot.com/2014/06/summer-begins-saturday-morning-at-651.html
Earth Closest to Sun Sat. Morning.
2014 Jan. 4.
Link >>> http://spacewatchtower.blogspot.com/2014/01/earth-closest-to-sun-sat-morning.html
Source: Glenn A. Walsh Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
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Glenn A. Walsh, Project Director,
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