Science on This Day: November 27 Anders Celsius's temperature scale, the Nobel Prizes, and the Soviet Mars 2 lander
Every day in science history offers a chance to connect the ideas students learn in class with the people, decisions and discoveries that helped shape the modern world. November 27 brings three very different stories: the birth of Anders Celsius, whose name is now used in temperature measurements around the world; Alfred Nobel’s decision to establish the Nobel Prizes; and a Soviet spacecraft that became the first human-made object to reach the surface of Mars.
These events connect physics, chemistry, space exploration and the relationship between science and society. They also offer an important reminder for students: scientific progress is not always a straight line from question to answer. Sometimes an idea changes after its creator has died, a person's legacy becomes more complicated over time, or a mission makes history even when it fails to achieve its main objective.
November 27, 1701: Anders Celsius is born
When students read a thermometer today, they may not give much thought to the person whose name appears beside the temperature. Anders Celsius, a Swedish astronomer and physicist born on November 27, 1701, helped develop one of the world's most widely used temperature scales. His story is a useful way to explore measurement, experimental evidence and how scientific conventions develop.
Celsius worked at Uppsala University in Sweden and studied astronomy as well as the behaviour of temperature and water. In 1742, he proposed a temperature scale based on the freezing and boiling points of water under specified conditions. His original version, however, was the reverse of the scale familiar to students today: zero represented the boiling point of water, while 100 represented its freezing point. After his death in 1744, the scale was reversed, producing the familiar arrangement in which water freezes at approximately 0°C and boils at approximately 100°C at standard atmospheric pressure.
This is a particularly useful detail for the classroom because it challenges the assumption that scientific systems have always existed in their present form. Celsius did not simply invent the modern thermometer scale exactly as we use it now. His work contributed to a system that was subsequently adapted. Scientific knowledge develops through the work of multiple people, and the conventions used to communicate measurements can change as well.
The Celsius scale is also a practical entry point into the difference between temperature and heat. Temperature describes how hot or cold something is, while heat refers to energy transferred because of a temperature difference. Students can compare Celsius with Fahrenheit and Kelvin, investigate why water's boiling point changes with atmospheric pressure, or discuss why scientists need agreed measurement standards when sharing results.
For a quick classroom activity, ask students to imagine that every country, laboratory or school used a different temperature scale. What problems might arise when comparing weather forecasts, laboratory results or medical measurements? Students could then convert a few temperatures between Celsius and Fahrenheit, or place Celsius and Kelvin on a shared scale to explore the relationship between everyday measurements and the scientific concept of absolute temperature.
The US National Institute of Standards and Technology's history of the kelvin provides useful context for the development of temperature measurement, including the original orientation of the Celsius scale.
November 27, 1895: Alfred Nobel signs the will that creates the Nobel Prizes
On November 27, 1895, Swedish inventor and industrialist Alfred Nobel signed his final will in Paris. In it, he directed that most of his remaining fortune should fund prizes recognising people whose work had conferred the greatest benefit on humanity. The will established five prize categories: physics, chemistry, physiology or medicine, literature, and peace.
Nobel had made his fortune through inventions and industrial enterprises, including the development and manufacture of explosives. Dynamite, which he patented in 1867, had important industrial uses such as mining and construction, but explosives could also be used in warfare. Nobel's legacy therefore offers students an opportunity to consider how inventions can have different consequences depending on how people use them.
It is tempting to tell this story as though one sudden moment of regret led Nobel to create the prizes, but the historical picture is more complicated. His correspondence and earlier wills show that he had considered ways to support knowledge and progress before signing his final will. What is clear is that the document he signed in 1895 committed the bulk of his estate to an ambitious programme of awards.
Turning that wish into reality was not straightforward. The will faced opposition and practical challenges, and it took several years to establish the organisation needed to administer the prizes. The first Nobel Prizes were awarded in 1901, five years after Nobel's death in 1896.
Today, the Nobel Prizes offer a way to discuss the impact of research across disciplines. The physics and chemistry prizes can highlight discoveries about matter, energy and the universe, while the prize in physiology or medicine connects to biology and human health.
The peace prize also raises questions about the relationship between scientific advances, public policy and the wellbeing of society. The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel was established later, in 1968, and was not one of the five categories in Nobel's original will.
In class, students could choose a scientific discovery or invention and make a case for the kind of recognition it deserves. They might consider whether awards should prioritise a fundamental discovery, a practical invention, a contribution to public health or work that solves a major environmental problem. Ask them to explain how they would judge the impact of a discovery, including who benefits, who might be harmed and what evidence would support their decision.
This activity can also prompt discussion about whether scientific achievement should be judged only by the discovery itself or by its wider consequences. Nobel's story demonstrates why the history of science is not just a record of inventions. It is also a history of the choices people make about how knowledge, money and technology should be used.
For more detail, the official Nobel Prize biography of Alfred Nobel explains the signing of the will and the development of the prizes.
November 27, 1971: Mars 2 reaches the Martian surface
More than a century after Nobel signed his will, a spacecraft travelling hundreds of millions of kilometres through space reached another world. On November 27, 1971, the Soviet Union's Mars 2 mission sent a lander towards the Martian surface. The lander crashed, but it became the first human-made object to reach the surface of Mars.
The mission was part of an early period of intense exploration of the Solar System. Mars 2 had been launched in May 1971 and travelled to the Red Planet with an orbiter and a lander. The orbiter successfully entered Martian orbit and could study the planet from above. The lander, however, entered the atmosphere at an angle that was too steep for a successful landing and was lost.
Calling Mars 2 a failure without qualification misses an important part of the story. Its lander did not complete its intended mission, but its impact marked a first in space exploration. The orbiter also continued operating around Mars, so the overall mission achieved results even though one of its major components failed. A few days later, on December 2, the Soviet Mars 3 mission achieved the first soft landing on Mars, although its lander transmitted for only a short time before communication was lost.
Mars 2 provides a useful way to explain the difference between reaching a destination, entering orbit, making a soft landing and operating successfully on a planet's surface. These are separate engineering challenges. A spacecraft must travel across interplanetary space, arrive at the right speed and trajectory, manage the transition into an atmosphere if there is one, and survive the conditions at its destination. A mission can succeed at some stages and fail at others.
Students can also investigate why Mars is difficult to explore. Its thin atmosphere provides some resistance to slow a lander, but not as much as Earth's atmosphere. Engineers must account for the planet's gravity, atmospheric conditions, communications delays and the limitations of the spacecraft's computers and instruments. The consequences of a small navigation or control error can be substantial when a spacecraft is moving at high speed and there is no opportunity for a human pilot to intervene directly.
A useful classroom challenge is to ask students to design a simple mission scorecard. They could assess Mars 2 against separate objectives: reaching Mars, entering orbit, landing safely, sending data and continuing scientific observations. Students should explain which goals were achieved and which were not. This helps them see why scientists and engineers evaluate complex missions using multiple measures rather than a single label of success or failure.
NASA's overview of deep-space exploration milestones provides further context for Mars 2 and later missions. Comparing early missions with modern rovers also helps students appreciate how engineering, computing and scientific instruments have developed over time.
Bringing November 27 into your science classroom
These three events work well together because they connect scientific measurement, ethical decision-making and engineering. They can be used as a short starter at the beginning of a lesson, as discussion prompts during a unit, or as a regular way to build students' understanding of how science develops over time.
For example, a temperature lesson could begin with the surprising fact that Celsius's original scale was upside down. A discussion about science and society could use Nobel's will to explore how people choose to recognise achievements and judge their effects. During a space science unit, Mars 2 can introduce the difference between an unsuccessful landing and a mission that still provides valuable results.
Students can also compare the three stories through a shared question: What does it mean for a scientific idea, invention or mission to be successful? There is no single answer. Success might mean creating a measurement system that others can use, establishing an award that recognises contributions to humanity, or achieving a milestone that helps future engineers learn how to land on another planet.
If you want to use science history regularly without spending time researching a new event each day, my November Science on This Day resource brings together 109 STEM stories across the month. It includes an interactive HTML version with filters and discussion questions, editable slides, a filterable spreadsheet and a PDF version. Teachers can select events that fit their current topic or use them as short daily classroom starters.
You can also explore the other science teaching resources in my store, including materials across physics, chemistry, biology, Earth and space science. There are free and paid resources available, so you can look for activities that fit your class and lesson plans.
What else happened around this date?
November 27 is part of a particularly varied stretch of science history. On November 28, students can explore Ferdinand Magellan's expedition through the strait at the southern tip of South America, the founding of the Royal Society in London in 1660, and the launch of Mariner 4, whose later flyby returned the first close-up images of Mars. These events offer connections to geography, scientific institutions and planetary exploration.
November 29 brings the birth of Christian Doppler, whose name is associated with the Doppler effect. This provides an accessible way to connect sound waves, moving sources and changing frequency. The date also offers stories about Richard Byrd's flight over the South Pole, pioneering heart surgery and the early history of video games. On November 30, students can learn about Jagadish Chandra Bose's work on radio waves and plant responses, the birth of Mark Twain in a year when Halley's Comet appeared, and the meteorite that struck Ann Hodges in Alabama in 1954.
If you are planning ahead, the December Science on This Day resource contains 132 STEM items spread across all 31 days of December. Like the November collection, it offers multiple formats to help teachers choose an event, display it for a class discussion or use it as a quick science-history starter.
Science history is most useful when it gives students a reason to ask questions about the science they are learning now. November 27 does that in three different ways: by showing how a familiar measurement scale evolved, how scientific achievement can be recognised, and how even an unsuccessful landing can become a milestone in planetary exploration.
Thanks for reading
Cheers and stay curious
Oliver - The Teaching Astrophysicist
