WBUR’s Science Friday will host a free event, the Science Friday Climate Fair, at WBUR’s CitySpace (890 Commonwealth Avenue, Boston) on April 18 at 4PM-8PM for kids of all ages to explore the ways scientists, educators and engineers are inventing solutions to climate change, creating sustainable systems and learning from the natural world. (Interactive stations are best suited for Grades 6-8.) Exhibitors include:

• Boston Children’s Museum
• Change Is Simple
• Harvard Forest Witness Tree
• MIT Sea Grant & Edgerton Center
• Native Plant Trust
• Science Friday

On Earth Day, April 22, 1PM-4PM, the Harvard Museums of Science and Culture (26 Oxford Street, Cambridge) will celebrate the 200th birthday of Alfred Russell Wallace (1823–1913), who discovered the theory of evolution by natural selection independently of Charles Darwin. HMSC will spotlight Wallace’s contributions to our understanding of biodiversity, highlighting why they are relevant to science today. Harvard students will share his legacy as a visionary scientist, a daring naturalist, and a passionate human rights advocate through stories and objects that reflect his professional achievements and travels in the Amazon and Indonesia. Free with regular museum admission. Free parking starting at noon at the 52 Oxford Street Garage.

The 2023 Massachusetts STEM Summit will be held on May 4 at the global headquarters of PTC (121 Seaport Blvd, Boston) with the theme, “Reimagining High School.”

The Christa McAuliffe Center at Framingham State University is hosting its free STEM festival, Science on State Street, on April 22, 2PM-6PM, in collaboration with the MetroWest STEM Education Network (MSEN). It’s open to all in the MetroWest area. With a particular focus on themes relating to planet Earth, and 136 exhibitors, the festival helps all explore environmental science,  environmental justice, and sustainability. This year’s festival will feature Climate Hope Concert by Multiverse,  interweaving climate science and music to build community and spark action. For more information contact the McAuliffe Center at cmc@framingham.edu or 509-626-4050.

The Christa McAuliffe Center at Framingham State University will host a free evening of stargazing and observation on April 28, 8:30PM-9:30PM (weather permitting), in front of May Hall on FSU’s campus in Framingham. For more information, email cmc@framingham.edu.

The Girl Scouts of Eastern Massachusetts will hold its STEM Fest at Camp Cedar Hill in Waltham on April 29, 9AM-1PM, for all Girl Scout levels. Register here. For more information, contact Eileen Koury at ekoury@gsema.org.

The smash-hit Black Hole Symphony will be performed at the Museum of Science by a live chamber orchestra under the dome of the Charles Hayden Planetarium, in an entrancing and immersive production. Performances will be 7PM-8PM each night, April 24-27. The show is recommended for ages 18+ but may be suitable for ages 8+ if they are accustomed to musical concerts. Tickets are $20 and do not include museum admission.

Black Hole Symphony is a symphonic journey through spacetime, exploring the unfolding story of supermassive black holes as engines of gravity, light, and creation. This show is a unique collaboration between astrophysicists of the Harvard-Smithsonian Center for Astrophysics and Black Hole Initiative with the musicians of the Multiverse Concert Series. Composer David Ibbett has sonified the light of black hole galaxies as musical notes and chords, in dramatic electro-symphonic score set to immersive 3-D visuals from the Charles Hayden Planetarium. Audiences will be plunged into deep space riding relativistic jets of plasma, guided through the dense dust torus, broad-line clouds, ultimately reaching the blazing accretion disk on the event horizon of a supermassive black hole.

The production is sponsored by MathWorks and the Massachusetts Music Teachers’ Association.

The Discovery Museums (177 Main Street, Acton) invites all to celebrate Earth Day on April 22, 10AM-1PM with friends from the American Chemical Society, local climate education and empowerment group Spring Forward, and the Acton Public Library. There will be a variety of family-friendly, hands-on activities related to local and global ecosystems including investigating algae,  learning about climate change, and building toward collective action.