Remote sensing is how scientists study a place without touching it, using satellites and aircraft to turn light into data. Here’s how it works, from wildfires to forests to reefs, shown through one of its boldest uses: mapping every shallow coral reef on the planet.

Picture a community and the wild animals that share its land, both depending on the same water, soil and seasons. Holding that balance is the heart of conservation.

Equal intelligence, opposite outcomes: identity is what decides. Three ideas about who you are from Being the Change, ASU’s changemaking course on purpose and growth.

Botanist Robin Wall Kimmerer writes that naming a plant is only the beginning. Understanding its relationships to pollinators, ecosystems and people is where deeper knowledge begins. SOS 100: Introduction to Sustainability at Arizona State University helps you build a systems-level understanding while opening a flexible path toward college credit and a career.

Holocaust and Genocide (HST 194) is a fully online, 3-credit Arizona State University course offered through ASU Universal Learner Courses. Start for just $25, complete the 8-week session and choose later whether to add transferable ASU credit for $400. Developed by leading Holocaust and genocide scholars. (Photo: Entrance to Auschwitz II-Birkenau. Oświęcim, Poland.)

Explore the living world in ASU’s BIO 100 — a 4-credit online biology course with lab. Begin for $25 with no application and choose later whether to add official ASU credit.

Earn affordable college credit with ASU’s PSY 101 online psychology course. Begin for $25 with no admission required, complete the coursework and decide after finishing whether to add transcripted credit.

Understanding early U.S. history helps explain how America’s institutions, conflicts and ideas continue to shape society today. ASU’s online Early U.S. History course (HST 109) requires no enrollment and is open to learners of all ages, with optional college credit.

Global affairs shapes everything from trade and security to climate policy and human rights. ASU’s online Introduction to Global Affairs course (INR 194), developed with the Council on Foreign Relations, is open to learners of all ages for $25, with optional college credit.