This year International Dark Sky Week (IDSW) will be celebrated April 13–20. That’s when everyone should make the effort to get acquainted or re-acquainted with the nighttime sky. This “celebration of the night sky” began in 2002, when 15-year old Jennifer Barlow introduced the idea in her hometown of Midlothian, Virginia. One year later, DarkSky International embraced the concept and promoted “Dark Sky Week” across the U.S, later expanding it to a worldwide celebration.

“We’re excited about all the night-sky activities being planned for Dark-Sky Week,” says Prof. James Lowenthal, President of DarkSky Massachusetts. This year, DarkSkyMass is coordinating with MIT’s Space Consortium, which has lined up a full slate of lectures and other events in conjunction with Space Week (April 20–26).

Here are IDSW activities planned across Massachusetts. (If you know of others, please contact Kelly Beatty with details.)

Saturday, April 18 (Northampton):
This year’s annual Night Sky Fest features a presentation by a specialist on moths as nocturnal pollinators and evening stargazing (8:00 to 9:30 pm).

Monday, April 20 (Cambridge):
Sidewalk stargazing (8:00 to 10:00 pm) at Brattle Plaza in Harvard Square.

Monday, April 20 (Nantucket):
Community stargazing event (8:00 to 9:30 pm) at Altar Rock in the Middle Moors, hosted by the Nantucket Conservation Foundation, Nantucket Lights, and the Maria Mitchell Association.

Tuesday, April 21 (Boston):
“What the Sky Teaches Us” (1:00 to 1:45 pm), a panel discussion at John F. Kennedy Library.

Tuesday, April 21 (Boston):
Stargazing (7:30 to 9:00 pm) at Mass Audubon’s Boston Nature Center. Co-sponsored by Boston Public Library and Amateur Telescope Makers of Boston.

Wednesday, April 22 (Belchertown):
Community stargazing (8:00 to 10:00 pm) at Foley Field.

Thursday, April 23 (Framingham):
Stargazing (8:00 to 9:30 pm) at the McAuliffe Center at Framingham State University. Co-sponsored by Skylight Astronomical Society.

Friday, April 24 (Boston):
Stargazing (8:00 to 10:00) at the Baseball Field on Boston Common. Cosponsored by DarkSky Massachusetts, the Space Consortium, Amateur Telescope Makers of Boston, #popscope , and UMass Boston. Rain/cloud date is Sunday, April 26th.

Saturday, April 25 (Boston):
Stargazing at John F. Kennedy Library with members of the UMass Boston astronomy club.

Monday, April 27 (Chelsea):
Community stargazing (7:30 to 9:00 pm) at the Veterans Home, 100 Summit Avenue. This event is co-sponsored by the Amateur Telescope Makers of Boston (ATMoB) and #popscope. Rain/cloud date: April 28.

In addition to all these group events, Lowenthal encourages everyone to get outside with friends and family to observe the night sky with Globe at Night. This citizen-science project requires no equipment or experience, yet its results have been used by researchers to track the growth of light pollution worldwide. Those data reveal that light pollution has increased globally by 10% per year since 2011.