Patents on the soles of your shoes...: astronomy

Showing posts with label astronomy. Show all posts

Sunday, September 27, 2015

Tonight's the night....

Copyrght © Françoise Herrmann

I've gotta a feeling...The Black Eyed Peas

Thursday, September 24, 2015

Total Eclipse of a Super(Blood)Moon (on Sept. 27, 2015)

Now… remember to watch the sky on September 27, 2015 when there will be a Total Eclipse of a Super(Blood)Moon. A Supermoon is a Full Moon or New Moon, at its closest position or perigee relative to earth, when the moon appears 12 to 14% bigger than a Micromoon. A BloodMoon is a moon positioned behind the earth, which has obstructed the sun’s blue rays.

From the perspective of the Earth, an eclipse happens when three celestial bodies are aligned almost in a straight line. The alignment is called a zyzygy (from the Greek word meaning "to be paired together"). In the case of a total eclipse of the moon, the sun, moon and earth are all aligned with the moon behind the earth, and the earth sandwhiched between the sun and moon. The earth thus obstructs light coming from the sun, casting its shadow on the moon. The eclipse occurs as the shadow is cast, partially or totally.

In contrast, in a total eclipse of the sun, the sun, earth and moon are also aligned, but it is the moon that is sandwhiched between the sun and the earth, and it is the moon that casts its shadow on earth, obstructing sunlight during the eclipse. This is why it is almost as dark as night during a total eclipse of the sun, occurring during the day. The next total ecliipse of the sun viewable in the US is on August 21, 2017.

There have only been 5 Total eclipses of a Super(Blood)Moon since 1900. After Sept. 27, 2015, the next one will happen in 2033… So, mark your calendars and set your alarm clocks to 7:47 pm (in California) for viewing the maximum eclipse!

No eye protection is required for viewing a total eclipse of a Super(Blood)moon. (Eye protection is only required for viewing a total eclipse of the sun).

The video animation from NASA included below shows what you can expect, if the sky is clear… The Supermoon should appear red as the earth will completely filter out the sun’s blue rays, which is why this Supermoon is also called a “Blood Moon”.

Enjoy the show!

Reference

NASA - National Aeronautics and Space Administration

https://www.nasa.gov/

Wednesday, September 23, 2015

Fall Equinox – First day of Autumn 2015

Today’s Google Doodle (in the US) reminds everyone that Sept. 23, 2015 is the first day of Autumn. Indeed the Fall semester at NYU is starting soon at the School of Professional Studies.

Here are a few key concepts of Astronomy… just in case you find patents in the sky…(and you will if you are covering climate change..)!

The first day of Autumn corresponds to the Fall Equinox, which is the day and time of the year when the sun is directly positioned on the Equator. This precise position and time of the sun over the Equator (for example, in California, at 1:22 am on Sept. 23, 2015) divides the duration of day and night into equal length, which explains the term “equinox” derived from the Latin aequinoctium combining aequus meaning “equal”, and nox meaning “night”. This special position of the sun happens just two times each year, once in the Fall, called the Fall Equinox, and once in the Spring, called the Spring Equinox.

The Summer and Winter Solstices, in contrast, mark the shortest and longest days of the year, depending on the hemisphere of the earth. The Solstice is recorded on the day the sun’s position is the farthest or at it’s zenith relative to the elliptical orbit of the Earth. In the Northern hemisphere this position occurs in June, marking the Summer Solstice relative to the Northern hemisphere and the Winter solstice relative to the Southern hemisphere. In the Southern hemisphere, the sun is at it’s zenith or the farthest from the Earth’s equator, in December, marking the Summer solstice relative to the Southern hemisphere and the Winter solstice relative to the Northern Hemisphere.

Because of the Earth’s tilt relative to the sun, when the sun is at it’s zenith in the Northern hemisphere, it is positioned directly over the Tropic of Cancer. In the Southern hemisphere, when the sun is at it’s zenith, it is positioned directly over the Tropic of Capricorn.

Below, a figure drawing of the solstices and equinoxes, extracted from the online version of the Encyclopedia Britannica.