#DYK there's a supermassive black hole at the center of our galaxy called Sagittarius A*? It's about 26,000 light years from Earth and 4.5 million times the mass of our Sun! Here it is flaring up after a possibly devouring an asteroid! s.si.edu/2zzB3pG #BlackHoleFriday pic.twitter.com/sfIGBw45HH

Today James Marshall "Jimi" Hendrix would have been 75 years old. #DYK he also served in the #USArmy with the 101st Airborne Division (Air Assault) from 1961 to 1962? pic.twitter.com/QDyJaaIYoi

#DYK that millions of women and girls around the world experience some form of physical or sexual violence in their lifetime? #16Days #EndVAW goo.gl/qdoKG3 pic.twitter.com/TaZEcvvMtJ

#DYK American bison remove snow from their food by sweeping it away using side to side motions of their muzzle. #SnowyAnimals Happy 1st of December pic.twitter.com/tXO5DRIcSW

Got that #Fridayfeeling? So do these guys! 🐘🐘🐘 #DYK play fighting helps young calves learn skills they can use later in life. pic.twitter.com/WXQufx33NN

TODAY is World AIDS Day! #DYK: Started in 1988, World AIDS Day was the first ever global health day. go.usa.gov/xn9Ud #WAD2017 pic.twitter.com/sBMNObWH8m

#DYK we’ve been developing vaccines for families for over 100 years #VaccinateForLife pic.twitter.com/J7o7WijFD0

#DYK Cactus pear is an important food crop in extremely dry areas, where it is called “bread of the poor”? bit.ly/2BdYCkk #ZeroHunger #climatechange pic.twitter.com/GHZSSLxt1a

Bonjour! Tanisi! ¡Hola! Nǐ hǎo! Ciao! #DYK There are over 200 languages spoken in Canada? That’s a lot of ways to say hello. #WorldHelloDay👋 pic.twitter.com/x8cpBBrdaj

#DYK that PET is 100% recyclable? Join us this week, as we take a pledge to stop PET from ending up in landfills. We urge you to take a moment to spread awareness about recycling. Take a pledge to recycle PET. #RecycleMe pic.twitter.com/isRt9f7GqI

#DYK 40,000+ Canadian Armed Forces members served in Afghanistan from 2001-2014? 158 lost their lives. #CanadaRemembers ow.ly/KCxX30gMll1 pic.twitter.com/BGf29iZmKo

Happy St Andrews Day! #DYK there are nearly as many Canadians of Scottish origin as there are people in Scotland? 🏴󠁧󠁢󠁳󠁣󠁴󠁿🇨🇦 pic.twitter.com/v7rDqqCx7C

#DYK? ICE HSI is the lead US law enforcement agency responsible for fighting human smuggling and human trafficking ice.gov/news/releases/… pic.twitter.com/ABsq5VjKm8

#DYK that lands we manage are home to 200,000 miles of fishable streams? pic.twitter.com/MlQH0hj9oo

#DYK we work with international partners to collect complaints about possible scams & protect consumers around the world using econsumer.gov? #econsumergov pic.twitter.com/Tzc1G1ypoX

Bordered by the Atlantic, Pacific and Arctic oceans, Canada is truly an ocean nation. #DYK that in 1997, Canada was the 1st country in the world to adopt an Oceans Act for #oceans management and sustainable development? pic.twitter.com/8zn60BM1pF

88.2% of sexual assault victims are women. #MYActionsMatter #DYK ow.ly/qDAE30gTvdE pic.twitter.com/sIUbrRlcix

The learning continues. #DYK that #apprenticeships can potentially be very lucrative? Learn a great professional trade, develop, and earn! pic.twitter.com/oUIrTlSS99

#DYK Cheetahs have “tear marks” that run from the inside corners of their eyes down to the outside edges of their mouth. These marks help reflect the glare of the sun when they are hunting during the day. #IntCheetahDay 4th Dec. internationalcheetahday.com/#HowToHelp pic.twitter.com/rBOjPOebja

#DYK On average, golfers that walk and carry their own clubs burn up to 1000 calories in a single round. pic.twitter.com/5keepuyTXe