Man returns to the moon
Half a century after Apollo 17, NASA launches Artemis 2, a new mission (with Italy)
“I'm at the bottom of the ladder. The Clemont's paws have just scratched the surface. The surface seems to be made of very small grains when you get close. It's almost dust. It's very fine. I come down from the Lem now. It's one small step for man but one giant leap for humanity." Impossible to forget the words spoken by the American astronaut Neil Armstrong relaunched by the exciting black and white commentary on Rai by Cagliari journalist Tito Stagno in a live broadcast that made history.
It was July 21, 1969, it was called the Apollo 11 mission and it wasn't the last. The man returned to lunar soil, the last time three years later, on December 14, 1972, with Eugene Cerman. Then nothing more. And now, more than fifty years later, here is Artemis 2. But this time NASA will not be alone but joined by the European Space Agency, the Canadians of the CSA, the Japanese of Jaxa and the Italians of the ASI.
2025 is also in the program with the Artemis 3 mission that will bring the first woman to the moon: will it be Samantha Cristoforetti? The Italian astronaut, the first woman in command of the international space station, is among the most accredited candidates.
In short, the moon continues to make us dream. Meanwhile, experts from the University of Cagliari are studying the dark side of matter, and Sardinia is at the center of futuristic projects.
Maria Francesca Chiappe
***
Fifty years after the Apollo 17 mission here is Artemis 2: Return to the Moon
It has been 50 years since a man last set foot on the moon. It was December 1972 when the Apollo 17 mission broke all records by remaining on the lunar surface for 75 hours. The last mission of the Apollo program, it was not only the longest lunar expedition in history, but it brought the first and only scientist to the moon, geologist Harrison Schmitt. Instructor of the Apollo program astronauts, he was chosen under pressure from the American scientific community. In three outings of more than 7 hours Schmitt collected, together with the commander Eugene Cerman, more than 100 kg of lunar rocks, moving on foot and with a lunar car.
After fifty years we look at the Apollo program and the race to the moon with great amazement. The technological means of the 60s were less sophisticated than the current ones, the risks of failure enormous, but NASA achieved what seemed unthinkable in just seven years. The race to the moon was born in the USA as a revenge, compared to the space successes of the Soviet Union. On May 25, 1961, a few weeks after the flight of Yuri Gagarin, the first man into space, newly elected President John Fitzgerald Kennedy declared to Congress: «I believe that this country must commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to earth. There has never been any space project more impressive to mankind or more important to space exploration; and none will be so difficult and so expensive to make…». Thus America launched the challenge to the Soviet Union, bringing from July 1969 to December 1972 12 men on the Moon, in six different missions. To achieve this result, NASA mobilized massive economic and human resources. Sixty thousand scientists and engineers, 400 thousand people and 20 thousand companies were employed in the Apollo program, which overall was a great success which however had its failures and saw the sacrifice of three astronauts. Virgil Grissom, Ed White and Roger Chaffee died on January 27, 1967 during a preflight test, due to a fire aboard the command module. Apollo 13, the third mission that was to land on the Moon, had a very serious accident that put the lives of the three astronauts at serious risk.
The race to the moon was a great technological incubator. In order to reach that goal, new technologies and technical solutions never seen before had to be developed, with more than 6,300 new products, which we still find in our daily lives today. If we have a smartphone in our pockets and a computer in our homes, we owe it to that electronic and IT revolution, born thanks to the impulse of the Apollo program. In the fabrics of our clothing we find some of the materials developed for the space program, and the velcro used today to close the shoes of the little ones closed the astronauts' suits. But in the end why hasn't we returned to the moon in these fifty years? For the Americans, the goal had been reached, the lunar missions no longer had the unconditional support of public opinion and it was impossible to go further, creating a permanent base on the Moon.
On the other front, the Soviets tried in secret to reach our satellite until 1972, but without success, seeing their N1 rocket explode three times without leaving the Earth's atmosphere. Later they preferred to engage in human permanence in space, being the first to build a permanent space station in orbit around the Earth. For all other nations the Moon was unattainable. Today the return of man to the moon seems to be within reach again. Last month, on December 11, the Artemis 1 mission ended which saw the first flight of a capsule to the Moon in 50 years. Far from the glories of the 60s, NASA has worked hard and economically to assemble a new rocket capable of taking us back to the Moon. If the Saturn V of the Apollo program had the famous Von Braun as father and important funds for its construction, the new SLS (Space Launch System) sees budgetary needs defining its development, so much so that for the maiden flight were mounted four engines developed for the Space Shuttle program. Taking off on November 16 from Cape Canaveral Air Force Base in Florida, the Artemis 1 mission was a success. In 25 days of stay in space he took the new Orion capsule to the Moon, testing the human survival systems with three dummies. Artemis 1 is only the first step, in fact this time we intend to return to the Moon to stay there.
NASA's goals are very ambitious and include the construction of a "Gateway", a small space station in lunar orbit which will be the "gateway" to descend and build a permanent base on the Moon. The timing for the realization depends on many factors, but the next mission has been scheduled for 2024. Artemis 2 will travel for about 21 days in space, flying over the Moon with four astronauts, three Americans and a Canadian. Unlike in the past, this new space program does not see NASA alone: the European space agency ESA, the Canadian CSA and the Japanese JAXA are partners in the Artemis programme. Even Italy with the ASI has its own role. After the success of the LiciaCube microsatellite in the planetary defense mission DART was launched with Artemis 1 ArgoMoon, another microsatellite that monitored the Orion capsule from the outside. In 2025 Artemis 3 should bring the first woman to the moon, while in subsequent missions it will be the turn of a European astronaut. Among the ESA astronauts two Italians: Samantha Cristoforetti and Luca Parmitano. Veterans of missions to the International Space Station, where they served as commanders, both are on the shortlist of possible candidates to land on the Moon. On December 14, 1972 Eugene Cerman, the last man on the moon, said: "As I take the last human step on the surface of the moon [...] we leave it as we arrived and, God willing, as we return, in peace and hope for all humanity".
Manuel Floris
***
From Star Wars to the University of Cagliari: «Let's study the dark side of matter»
The dark side of the Universe isn't just the stuff of sci-fi movies. The Star Wars saga made it the center of a story of enormous cinematic success, but a mysterious and apparently unobtainable part must really exist in that infinite space we call the Cosmos. Scientists from all over the world are sure of it, and those who do research in Cagliari as well: right here for more than ten years a working group has been set up that deals with hunting down "dark matter", from the name of the project: DarkSide. The goal is to find the signals that confirm the existence of this something, which we don't quite know what it is but must exist because otherwise "the movement of galaxies would not be explained, whose rotation observed from the Earth is different from that would expect from their shape seen through a telescope.'
Speaking is Alessandro Cardini, 57, research manager and director of the Cagliari section of the National Institute of Nuclear Physics: the research body that studies the infinitely small, the foundations of matter. Born in Lodi, graduated in Physics in Pisa in 1989, studied at the Ucla University of California and, for three years, at the University of Rome, since 2000 he has been in the Sardinian capital where, since 2018, he has been leading the group of Sardinian researchers engaged in the study of the candidate site to host (in Lula) the Einstein Telescope, the future large detector of gravitational waves.
"The preliminary results are more than encouraging, it would be a perfect location for this tool," he says. His group is made up of about 110 men and women, many of whom are Sardinian: they are the research and administrative support staff of the Infn of Cagliari plus the professors and associate researchers who work on the experiments. "We are a small section but for another experiment called Lhcb" which studies the differences between matter and antimatter. «Our group has 19 people: it is the largest in Italy. We play well as Sardinians ». Therefore, on the Island a group of physicists studies the deepest Universe, tries to reveal its mysteries and makes real Hollywood film material, also trying to create the material that serves as a target for the search for that dark matter that cannot be seen but there is. «Something unique in the world to contribute to research».
Professor, what is this dark matter? The name immediately brings to mind Darth Vader and Luke Skywalker from the film Star Wars.
"We do not know. The hypothesis, linked to the anomalous rotation of the galaxies, is that there is an additional mass within these immense agglomerations of stars, something that is part of their mass but cannot be seen. After all, we know only 4 percent of the elements of the universe. We lack the remaining 96 percent.
What about antimatter?
«Scientists imagine that in the Big Bang, the moment of birth of the Universe, as much matter as antimatter was created due to the conservation principle. Where did that antimatter go? You can't see it. So either it's not there, or it's gone. It disintegrates into energy when it meets matter. In Nature it exists but our world cannot sustain its existence for long. In some cases it can be produced, perhaps from a radioactive source. At Cern in Geneva, antimatter particles are created and the differences in behavior between the two states are studied to understand why the Universe is made of matter».
If you can't see dark matter, how can you find it?
“The thesis is that it evades detectors but not entirely. Then: the Solar System moves in a wind of dark matter and the Earth in its revolution around its star for a stretch goes against this wind. So we expect seasonal variations which, if found, could be an indication of the presence of dark matter."
What role does Sardinia play in all of this?
"Important. A detector is under construction at the Gran Sasso research center, i.e. a tank of liquid Argon gas on which dark matter could show its own visible signal. We could start within five years, but we need an environment protected from cosmic rays and furthermore Argon is by its nature slightly radioactive, so it can distort the research. We need a low-radioactive Argon that we get from a mine in the US and bring to the Nuraxi Figus one in Gonnesa, where a 350-metre high distillation column is under construction, unique in the world, which will separate the radioactive from the non-radioactive Argon. The Island therefore also participates as responsible for what will form the raw material, the heart of the detector».
Why "also"? What else happens to us?
«Because we want to have the Einstein Telescope in Lula for the fundamental study of gravitational waves, that is, the perturbations generated by cosmic cataclysms such as the meeting of two black holes. Events that produce perturbations in the structure of space-time. Capturing these waves means observing cosmic cataclysms that may have occurred billions of years ago».
What is the importance of the Einstein Telescope?
«Many of these phenomena do not emit visible light, so a new sense was needed to capture them. Gravitational waves were observed for the first time in 2015 in the USA and then in Pisa: since then a new astronomy has begun. You can see something with the telescope, with the strategic San Basilio radio telescope and even now with gravitational waves. Using eyes and ears the phenomenon is better understood. Gravitational waves propagate for enormous distances without being absorbed, contrary to what happens to light, and arrive clearer to us. They are a time machine that can push us close to the Big Bang, the birth of the Universe 13.8 billion years ago. Here, the Einstein Telescope has the ability to take us so far back in time: an underground triangle with three tunnels of 10 kilometers each. We want to do it in Sardinia, in Lula, because it is a very sensitive instrument to vibrations and there human activity is reduced to a minimum. Also there is very little seismic activity.
What task do you have?
«Our group has been working on the project for 5 years. We are contributing to the characterization of the Sos Enattos site using tools that make us understand what physical conditions there are 200 meters below the ground. The preliminary results are more than encouraging. There is a deafening silence, the Einstein Telescope would find its perfect location. It would be a miniature Cern».
Recently the successful nuclear fusion experiment made headlines. There was talk of a revolutionary discovery and clean energy. What is it about?
“Fusion is the joining of two atoms into one with the release of additional energy, which moves forward. A procedure opposite to nuclear fission, the one used today in atomic power plants, with which the atom is divided: it is split in two, releasing usable energy. In fusion deuterium and tritium are involved, isotopes of hydrogen but heavier, which when put together produce a helium atom releasing a neutron: that is, the additional energy produced by the reaction. What happens in the stars. But doing it in the laboratory is very complicated, because bringing two atoms together requires enormous forces. The experiment mentioned above was carried out in the USA, where 192 very powerful lasers were directed towards an object the size of a peppercorn, bringing the temperature to 3 million degrees. In the end, more energy came out than was put in».
Why would it be a revolutionary discovery?
“Hydrogen can be easily obtained from water. It would be a matter of having an always-on power plant that produces free and infinite energy for everyone without radioactivity and carbon dioxide».
Isn't it dangerous to create an artificial sun? Don't you risk being instantly pulverized?
«No, because in order for the system to work, it needs a suitable environment that is difficult to obtain. If the pressure compressing the atoms disappeared, this star would immediately go out. If you lose control, the star will naturally go out without any consequences. It is not like the nuclear power station which, with the core meltdown, would cause different consequences. Experiments are also underway in Europe, but instead of lasers, magnetic fields are used to reconstruct the star in the laboratory".
Finally: they discovered two Earth-like planets 16 light-years away, possibly habitable. Is there intelligent life in the universe?
“Exceeding the speed of light, 300,000 kilometers per second, is difficult. Maybe impossible. So even having such fast spaceships it would take 16 years to get to those worlds. Today the most distant human object from the earth are the two Voyager probes, launched in the late 1970s and just exiting the solar system. They travel at around 60,000 kilometers per hour. To get further you will have to invent something new. About life forms, in such a large universe it would be strange to be the only ones. Even if we were the only civilization in the Milky Way, there are billions more galaxies in the Cosmos. But even if they exist, the probability of being able to contact them is very low. Of course it would be nice to discover a means of transport to travel at speeds higher than light ».
Andrea Manunza
***
The curiosities of the little ones
Waiting for the Neanderthal comet: February 1 visible to the naked eye
Comets are celestial objects that have always fascinated and amazed man. They appear in the night sky suddenly, grow in brightness, and display a tail that grows over time. As quickly as they appear, they disappear just as quickly, becoming fleeting, mysterious and seemingly unpredictable objects. Comet C/2022 E3 (ZTF), amicably renamed “The Neanderthal Comet,” may become visible later this month because it last passed close to the Sun about 50,000 years ago.
On January 12 it passed close to the Sun and on February 1 it will pass close to the Earth, becoming visible to the naked eye. Comets are what remains of the origins of the Solar System. Agglomerations of ice and dust, they orbit the Sun and are mostly found beyond Neptune. When comets approach the Sun, the light from our star warms them and as they melt they lose chunks of ice into space. Driven by the solar wind, a wind that originates in the Sun, the chunks of ice are lost in space, forming a tail that grows as it gets closer to the Sun.
The tail is always in the opposite direction to the Sun. When the comet approaches our star, the tail follows it, while when it moves away, the tail precedes it. Between late January and early February the Neanderthal comet will pass close to the Earth. To look for it with the naked eye or with small binoculars, it will be necessary to point to the constellation of the Giraffe, between the Big and the Little Dipper, hoping that it is bright enough.
***
What is the Solar System?
Our planet is part of a large family called the Solar System. The Earth with 7 other planets revolves around the Sun. In addition to the planets in the Solar System we have dwarf planets, asteroids and comets.
Why do the planets revolve around the Sun?
The Sun keeps the planets close to it, as the Earth keeps us on its surface. The "glue" that keeps us from flying through space is called gravity, which keeps the planets moving around the sun.
The planets go around the Sun in paths we call orbits. The orbits resemble elongated circles that we call ellipses.
Are the planets visible in the sky?
Five planets are visible appearing as stars. They are Mercury, Venus, Mars, Jupiter and Saturn.
What is Pluto?
Pluto is a small world that belongs to the family of dwarf planets. It is further away than Neptune and is smaller than the Moon.
Are all planets like Earth?
No, the Earth is a very special place, it's rocky and just the right distance from the Sun not to be too hot or too cold, so it's suitable for life. There are three other rocky planets in the Solar System: Mercury, Venus and Mars. Jupiter, Saturn, Uranus and Neptune are gaseous planets.
How big is the Solar System?
If we reduced the size of the Sun to that of a €1 coin, the Earth would be about 3 paces away, Jupiter 15 paces, Saturn 29 paces and Neptune, the planet farthest from the Sun, about 90 paces.
How fast do planets move?
The fastest moving planet is Mercury, it completes one revolution around the Sun in 88 days. Moving away from the Sun, the planets move more slowly, the Earth takes a year to go around the Sun, Saturn almost 30 years.
Which is the hottest and the coldest?
Venus is the hottest planet, on its surface the temperature is 464°C, such as to melt lead. The coldest planets are Uranus and Neptune, the temperature is around -200°C and for that they are considered gaseous and frozen planets.
