Science on This Day: December 7 | Apollo 17, Jupiter Exploration, and Gerard Kuiper
December 7 is a useful date for exploring how scientists study worlds beyond Earth. In 1972, astronauts began the final Apollo mission to land on the Moon and took one of the most recognisable photographs of our planet. In 1995, NASA’s Galileo spacecraft reached Jupiter, beginning a detailed investigation of the giant planet and its moons. The date also marks the birth of Dutch-born astronomer Gerard Kuiper, whose work helped establish planetary science as an important field of research.
These three events offer science teachers opportunities to connect astronomy with geology, physics, technology, and the way scientific knowledge develops over time.
December 7, 1972: Apollo 17 launches and captures “The Blue Marble”
In the early hours of December 7, 1972, a Saturn V rocket lifted off from Kennedy Space Center in Florida carrying Apollo 17 astronauts Eugene Cernan, Ronald Evans, and Harrison Schmitt towards the Moon. It was the final crewed lunar landing mission of NASA’s Apollo programme and the first night-time launch of a Saturn V rocket.
The crew had different roles. Cernan commanded the mission, Evans remained in orbit around the Moon aboard the command module, and Schmitt operated the lunar module alongside Cernan during their landing. Schmitt was also a trained geologist, making him the first professional scientist to walk on the Moon. His geological expertise helped the crew investigate the Moon’s history through its rocks, landscape, and impact features.
Apollo 17 landed in the Taurus-Littrow valley on December 11. The astronauts spent more than three days on the lunar surface, conducted experiments, travelled in the lunar rover, and collected approximately 110 kilograms of rock and soil samples. Those samples remain valuable to researchers studying how the Moon formed and changed over billions of years.
The mission also produced one of the most widely recognised photographs in history. On the journey to the Moon, the crew photographed Earth from space. Known as “The Blue Marble,” the image shows our planet with Africa, the Arabian Peninsula, and Antarctica visible beneath extensive cloud cover. It was taken on December 7, 1972, and offered a striking view of Earth as a single, interconnected world.
The photograph was not the first image of Earth from space, but its composition and clarity helped make it especially influential. It provides a useful starting point for discussing Earth systems, weather, oceans, continents, and the way our perspective changes when we view our planet from far away.
Classroom connection: What can one photograph tell us?
Display The Blue Marble without immediately giving students its title or date. Ask them to describe what they can observe, what they can infer, and what they cannot determine from the image alone. For example, students might identify continents and cloud systems, infer that the image was taken from space, and recognise that a single photograph cannot show how Earth’s climate changes over time.
This is also a good opportunity to discuss the difference between observation and interpretation. Students can compare the image with modern satellite images and consider how instruments, image processing, viewing angles, and the purpose of a photograph affect the information it provides.
You can also connect Apollo 17 with geology. Why would scientists choose a particular lunar landing site? What can rock samples reveal that photographs cannot? These questions help students see crewed spaceflight as a scientific investigation rather than simply a technological achievement.
NASA’s Apollo 17 mission history and its The Blue Marble resource provide useful background and classroom visuals.
December 7, 1995: Galileo reaches Jupiter
On December 7, 1995, NASA’s Galileo spacecraft reached Jupiter after a journey that began with its launch aboard the Space Shuttle Atlantis in October 1989. The mission had taken a longer route through the Solar System, using gravity assists from Venus and Earth to build up the speed needed to reach the distant planet.
Galileo’s arrival was a major milestone: it became the first spacecraft to orbit Jupiter. Rather than simply passing the planet once, it could return repeatedly to study Jupiter and its moons. Its observations helped scientists investigate the planet’s atmosphere, magnetic field, radiation environment, and complex family of satellites.
The date is especially significant because Galileo carried a separate atmospheric probe. Released months earlier, the probe entered Jupiter’s atmosphere on December 7 and transmitted measurements for around 58 minutes as it descended. It measured conditions including temperature, pressure, and the composition of the atmosphere before the increasing pressure and temperature ended its operation.
The probe’s measurements revealed details about Jupiter’s atmosphere that could not be obtained from distant observations alone. Meanwhile, the main spacecraft began its orbital mission, returning observations of Jupiter and its moons over several years. Galileo studied the large moons Io, Europa, Ganymede, and Callisto, helping researchers understand their very different surfaces and geological histories.
The mission was not without problems. Galileo’s high-gain antenna failed to deploy fully, limiting how much data it could transmit. Engineers and scientists adapted the mission and developed ways to return much of its planned science using the spacecraft’s lower-gain antenna and improved software. This is an excellent example of how space missions depend not only on designing equipment, but also on responding creatively when that equipment does not work as intended.
Classroom connection: How do we investigate a planet we cannot visit?
Ask students to design an investigation of Jupiter. What could they learn using a telescope from Earth? What additional information would an orbiting spacecraft provide? What could an atmospheric probe measure that an orbiter could not?
Students can organise their answers into three categories: observations made from a distance, measurements made by an orbiter, and measurements collected by a probe entering the atmosphere. They can then discuss the advantages, limitations, risks, and costs of each approach.
Galileo also offers a real-world case study in engineering resilience. Present the failed antenna as a problem for students to solve: how might a spacecraft continue sending scientific data when its main antenna cannot open? Encourage them to distinguish a creative engineering solution from simply ignoring the problem.
NASA’s Galileo mission page and its Galileo atmospheric probe overview provide further information for lessons on planetary exploration, forces, energy, and engineering.
December 7, 1905: The birth of Gerard Kuiper
Gerard Peter Kuiper was born in the Netherlands on December 7, 1905. He later became one of the most influential planetary scientists of the twentieth century. After studying astronomy at Leiden University, he moved to the United States, where he worked at several observatories and eventually founded the Lunar and Planetary Laboratory at the University of Arizona.
Kuiper’s research helped change how astronomers understood the Solar System. In 1944, he identified methane in the atmosphere of Saturn’s moon Titan. He discovered Miranda, a moon of Uranus, in 1948, and Nereid, a moon of Neptune, in 1949. His work also contributed to understanding planetary atmospheres, the composition of Saturn’s rings, and the formation of the Solar System.
Kuiper is particularly remembered because the Kuiper Belt, a region beyond Neptune containing many small icy bodies, is named in his honour. In 1951, he proposed that a population of icy objects could exist beyond the orbit of Neptune. The region is now known to contain dwarf planets and many smaller objects, including bodies that can become short-period comets.
It is worth explaining that Kuiper did not discover the Kuiper Belt as we understand it today. His proposal was an important part of the scientific thinking that led to the modern concept, while the existence and extent of the region were established through later observations. This distinction makes his story particularly useful for teaching how science develops: a hypothesis can influence future research even when the evidence needed to confirm it arrives decades later.
Kuiper also helped develop methods for studying planetary surfaces and atmospheres, and he contributed to lunar research that supported later space missions. His career demonstrates that space exploration depends on a long chain of work, from observations and theoretical ideas to instruments, spacecraft, and the interpretation of new data.
Classroom connection: How does a scientific idea become accepted?
Ask students to investigate one of Kuiper’s contributions, such as the discovery of Titan’s methane-rich atmosphere, his discovery of planetary moons, or his proposal about icy objects beyond Neptune. Have them identify what scientists knew at the time, what Kuiper contributed, and what later observations added.
Students can then consider why a scientific idea may be proposed long before it can be tested properly. What technology would be needed to detect small, distant objects? How might better telescopes and spacecraft change what scientists can observe? This activity reinforces the idea that science is a process of building, testing, and revising explanations, rather than a list of discoveries made in isolation.
For further reading, NASA’s biography of Gerard Kuiper outlines his contributions to planetary science.
Using Science on This Day in your classroom
These three December 7 events can be used together or separately. Apollo 17 connects geology with spaceflight and Earth observation. Galileo provides a case study in planetary science and engineering problem-solving. Kuiper’s career highlights how observations and hypotheses can shape research for generations.
A short daily science-history activity can help students connect familiar scientific concepts with the people, instruments, and decisions behind scientific discoveries. It can also provide a low-preparation starter for discussion, a retrieval-practice prompt, or a short research task.
My December Science on This Day activity set includes 132 science and STEM events across the 31 days of December. It offers several ways to use the material: an interactive HTML version with date and subject filters, a classroom display mode, discussion questions and favourites; editable slides; a filterable spreadsheet; and a printable PDF. You can select an event for a quick starter or use the discussion question to begin a longer conversation.
For more astronomy-themed classroom material, explore the other resources in my store, including the Black Holes: Strange But True Facts and 2 Truths and a Lie activity. These resources offer another way to encourage students to question claims, discuss evidence, and develop their understanding of space science.
What else happened in science during December?
December has plenty more events to draw on for science lessons. On December 10, the first Nobel Prizes were awarded in 1901, while the Hubble Space Telescope’s corrective optics were installed during a servicing mission in 1993. December 11 marks Apollo 17’s landing on the Moon in 1972 and the birth of microbiologist Robert Koch in 1843.
On December 14, Max Planck presented his work that helped launch quantum theory, and NASA’s Mariner 2 spacecraft made its historic flyby of Venus in 1962. December 17 brings together the Wright brothers’ first powered flight in 1903 and the discovery of nuclear fission in 1938. Later in the month, Apollo 8 launched on December 21, the famous Earthrise photograph was taken on December 24, and the James Webb Space Telescope launched on December 25, 2021.
These events span physics, biology, chemistry, engineering, Earth science, and astronomy, making them useful for connecting topics across a school science curriculum. A single historical event can prompt students to revisit a scientific concept, consider how technology changes what people can investigate, or ask how a discovery continues to affect research today.
Thanks for reading
Cheers and stay curious
Oliver - The Teaching Astrophysicist
