International Dark Sky Week 2018 Begins Sunday, April 15

Summary: International Dark Sky Week 2018 begins Sunday, April 15, and ends Saturday, April 21, as a week for night sky appreciation via dimmed outdoor lights.

“Girl Gazing at Night Sky at Base of Dunes”: Great Sand Dunes National Park and Preserve, south central Colorado; Nov. 29, 2014; photo by National Park Service (NPS)/Patrick Myers: Great Sand Dunes National Park and Preserve, CC BY 2.0, via Flickr

International Dark Sky Week 2018 begins Sunday, April 15, and ends Saturday, April 21, as a weeklong awareness of reducing light pollution, via dimmed outdoor lights, and appreciation of the night sky, via increased visibility of nighttime’s astronomical objects.

The annual celebration of International Dark Sky Week is scheduled to coincide with April’s new moon. April 2018’s moon reaches newness Monday, April 16, at 01:57 Coordinated Universal Time (Sunday, April 15, at 9:57 p.m. Eastern Daylight Time).

The new moon begins the lunar cycle as the darkest of the moon’s eight phases. From Earth’s perspective, the lunar placement between Earth and sun accounts for the new moon’s invisibility to the unaided eye. The moon’s lit side faces toward the sun while its dark side, with no reflected light, faces Earth.

A moonless night sky, however, does not last. The moon has been moving about 12 degrees to the sun’s left every day. The eastward lunar movement accounts for a daily lag of about 50 minutes behind the sun.

April’s new moon transitions by Tuesday, April 17, to the thin crescent of visibility that characterizes the waxing crescent, the second lunar phase. By the waxing crescent phase, the moon is lagging sufficiently behind the sun to yield its evening sliver of visibility in the west after sunset.

International Dark Sky Week 2018 ends with the week’s last waxing crescent Saturday, April 21. The first quarter moon Sunday, April 22, has greater surface illumination with its placement 90 degrees to the sun’s left. The moon’s daily lag has now grown to about six hours, so the first quarter moon shines lengthily in the night sky.

International Dark Sky Week’s convenient occurrence during a week of less moonlight encourages appreciation of nighttime’s other astronomical objects. International Dark Sky Week 2018 coincides with the annual Lyrids, which shower meteors between April 16 and April 26. International Dark Sky Week 2018 closes on the Lyrids’ first of three peak days.

International Dark Sky Week’s mission transcend a week’s worth of night skies with less light via the natural phenomenon of lunar phases. The event considers the unnatural interference of Earth-based light pollution with dark sky appreciation.

The Arizona-based International Dark Sky Association identifies the nighttime environment as “a crucial natural resource” that is undergoing radical changes as a result of outdoor lighting-caused skyglow. Dimming outdoor lighting during International Dark Sky Week mitigates the problem of light pollution and promotes dark sky visibility.

How did International Dark Sky Week start? In 2002, Jennifer Barlow, then a 15-year-old high school student in Midlothian, Virginia, was inspired by an internet message board suggestion to dedicate one night each year to appreciate the night sky by dimming outdoor lights. In summer 2002, the high schooler emailed the International Dark-Sky Association (IDA). Robert “Bob” Gent, then IDA’s public relations director, offered his help. Momentum from Barlow’s outreach culminated in the observation of the first National Dark Sky Week in April 2003.

In a July 19, 2006, interview with Sky & Telescope, Barlow expressed to then S&T intern Monica Bobra her hope for expansion of National Dark Sky Week into International Dark Sky Week.

“It would be even better to get the whole world involved!” Barlow shared.

In 2009, the United States’ National Dark Sky Week premiered as International Dark Sky Week. The first International Dark Sky Week was observed Monday, April 20, through Sunday, April 26, 2009.

Dark Sky Week celebrates its 10th anniversary as an international event in 2018. Dark Sky Week was a national event for six years from 2003 through 2008.

The takeaway for International Dark Sky Week 2018, which begins Sunday, April 15, and ends Saturday, 21, is that the annual worldwide weeklong event coincides with April’s new moon to ease appreciation of the wonders of night skies darkened via Earth’s dimmed outdoor lights and the sky’s dimmed moon.

Contact details:
International Dark-Sky Association
3223 North First Avenue
Tucson AZ 85719

phone: (239) 293-3198
fax: (239) 293-3192
website: https://www.darksky.org
faq: http://www.darksky.org/resources/faq/

stargazer at Glacier Point, Yosemite National Park, western Sierra Nevada, Northern California; photo by National Park Service (NPS)/Jessica Zamudio: Yosemite National Park California via National Park Service

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

“Girl Gazing at Night Sky at Base of Dunes”: Great Sand Dunes National Park and Preserve, south central Colorado; Nov. 29, 2014; photo by National Park Service (NPS)/Patrick Myers: Great Sand Dunes National Park and Preserve, CC BY 2.0, via Flickr @ https://www.flickr.com/photos/greatsanddunesnpp/17176993687

stargazer at Glacier Point, Yosemite National Park, western Sierra Nevada, Northern California; photo by National Park Service (NPS)/Jessica Zamudio: Yosemite National Park California via National Park Service @ https://www.nps.gov/yose/planyourvisit/stargazing.htm

For further information:

“5 Ways to Celebrate Dark Sky Week!” IDA International Dark-Sky Association > Advocacy. Oct. 12, 2016.
Available @ http://www.darksky.org/5-ways-to-celebrate-dark-sky-week/

Bobra, Monica. “Jennifer Barlow: Dark-Sky Devotee.” Sky & Telescope > Astronomy Resources. July 19, 2006.
Available @ http://www.skyandtelescope.com/astronomy-resources/jennifer-barlow-dark-sky-devotee/

Espenak, Fred. “Phases of the Moon: 2001 to 2100 Universal Time.” Astro Pixels > Ephemeris > Moon > Six Millennium Catalog of Phases of the Moon.
Available @ http://www.astropixels.com/ephemeris/phasescat/phases2001.html

The International Dark-Sky Association. Fighting Light Pollution: Smart Lighting Solutions for Individuals and Communities. Mechanicsburg PA: Stackpole Books, 2012.

“International Dark Sky Week 2018.” IDA International Dark-Sky Association > Events. Oct. 12, 2016.
Available @ http://www.darksky.org/dark-sky-week-2017/

“International Dark Sky Week 2018.” IDA International Dark-Sky Association > Events. Dec. 28, 2017.
Available @ http://www.darksky.org/dark-sky-week-2018/

Marriner, Derdriu. "Star-Filled Four Corners States Claim 16 International Dark Sky Parks." Earth and Space News. Wednesday, Nov. 9, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/star-filled-four-corners-states-claim.htmlbr />

Marriner, Derdriu. "United States Has 30 International Dark Sky Parks as of October 2016." Earth and Space News. Wednesday, Nov. 2, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/united-states-has-30-international-dark.html

“Moon Phases April 2018.” Calendar-12.com > Moon Calendar > 2018.
Available @ https://www.calendar-12.com/moon_calendar/2018/april

“Robert Lee Gent Astronomer.” Prabook.
Available @ https://prabook.com/web/robert_lee.gent/1371101