Noemí Pinilla-Alonso is Asturian from Oviedo and says that as a child she had everything against her to do what she liked the most: gaze at the stars. It was almost always cloudy there, but every summer his family went to Toro, in Zamora, where his parents, a salesperson and a teacher come from. The “skies of Castile” allowed him to discover the first constellations.

That girl is now directing one of the most ambitious campaigns to explore the outer reaches of our Solar System in history. Your main objective is to use the space telescope James Webb to scrutinize what lies beyond Neptune, the last planet in the Solar System.

Pinilla-Alonso’s life was changed by one of the greatest astronomical controversies of this century. The discovery of several distant bodies larger than Pluto led to an intense international debate that ended with the defenestration of the planet, which became a dwarf planet.

For the first time, the largest space telescope in history will be able to observe in detail some of these worlds (Eris, Make Make, Haumea) and search in them for the basic ingredients for life. At the age of 50, Pinilla-Alonso, an astronomer at the Space Institute of the Central University of Florida (USA), will be the coordinator of these observations. Thanks to Webb, The researcher will also explore Ariel, Umbriel, Titania and Oberon, the unknown moons of Uranus. But his main interest is studying the trans-Neptunian bodies, a vast ring of millions of unknown objects that extends beyond Neptune.

Ask. Why are you interested in the territory beyond Neptune?

Answer. Trans-Neptunian objects are one of the largest structures in the Solar System, and it is also one of the least known. We know that this belt of icy objects beyond Neptune is the origin of comets. We know that it contains large objects such as Pluto, about 2,000 kilometers in diameter, and smaller ones, less than 10 km. There may be billions of them, although for now we only know about 3,000. We have no idea what is on its surface. Water has been detected, but we do not know how much there is. We also do not know if this is the most abundant element or if there are other ices of methane, methanol, nitrogen or carbon dioxide. And it is very important because these are the seeds of life.

P. Can life on Earth have its origin in these bodies?

R. Exactly. In comets, ice turns into gas and dust. We know that there are compounds in them such as methanol, carbon monoxide, key elements for life. At the moments of greatest chaos in the history of the Solar System, the resonance of Jupiter and Saturn occurred. Each one orbited around the Sun in its own way, but at one point they gravitationally connected and began to move in a coordinated fashion. They are the two largest planets and they began to move in unison, with which they swept everything around them, expelling planetesimals, smaller bodies, as if it were a large billiard. Many of these bodies were shot into the Solar System or out. At those times there were a lot of collisions on the Moon and on Earth. And that could be the moment when water ice and organic compounds reached our planet and the origin of life took place. These two giant planets also caused Uranus and Neptune to migrate out of the Solar System. And they in turn cleaned the outside areas. All trans-Neptunian objects are thought to be originally 10 times more massive than Earth. But most of them disappeared. Now only 10% of what was left remains. What we want to know is all the details of what happened.

P. Why the telescope James Webb is decisive in the study of these objects?

R. Although it sounds cliché, in the knowledge of our Solar System there are a lot of unanswered questions. For example, we do not fully understand how it was formed, as well as the planetasimals, the fragments that could come together to form the planets. Theoretical models that attempt to explain this only partially succeed. The James Webb it is going to be a great space telescope that will observe the infrared universe. That means that it will reveal to us a universe that has remained hidden until now. On the subject of trans-Neptunian objects, he is going to show what are the materials that make them up. This will allow us to investigate the processes that affect them from their formation, billions of years ago, to the present time.

We are much more blind to dangerous asteroids since it closed Arecibo

P. Couldn’t we do it with ground-based telescopes?

R. Since the first trans-Neptunian object other than Pluto was discovered in 1992, many of these bodies have been detected. Seen from Earth they are not very bright and the data we can obtain with surface telescopes is limited. Recently, we have discovered that there are not only larger bodies, but also smaller, less shiny ones in which water is mixed with other materials. What is impossible from the ground is to characterize these materials. We assume that those that are very red have complex organics, those key compounds for life, but it must be confirmed and with the Webb we can do it.

P. What objects do your observation projects focus on? Webb?

R. Probe New Horizons NASA has shown us in detail the surface of Pluto. It has shown that this dwarf planet has an atmosphere and that there is transfer of material with the surface. We know how far its glaciers, craters and ice deposits are. In contrast, other even larger objects are largely unknown. We have now achieved almost 100 hours of guaranteed time with the Webb to observe the largest trans-Neptunians: Eris, Make Make, and Haumea, as well as Pluto and Charon.

P. Will they be able to expand the knowledge of smaller bodies?

R. Yes. We have another project for that. With the few trans-Neptunians that have been observed so far, we know that there is a lot of diversity: objects as dark as asteroids that must be made of coal, and others as bright as freshly fallen snow, like Haumea. To know what is in this belt we have to study very different objects. We will study 60 of them.

P. Could these studies reveal the existence of a new planet at the limits of our Solar System?

R. Right now there are two currents with respect to that planet X; is one of the open questions. A group continues to study the most distant trans-Neptunians to see if their orbits are aligned and respond to the influence of that outer planet. There is another group that thinks that this alignment does not exist and that many more objects of this type must be discovered and observed in order to study their behavior. The James Webb It is not the right tool to search or discover planets in our solar system due to its small field of view. However, it would be the ideal tool to study its surface if another telescope, such as the Vera Rubin, that he’s going to track the entire sky in the next decade, find out.

P. You are an Associate Principal Investigator of Arecibo, that it was the largest radio telescope in the world and that today it is demolished and closed. Is there a way to recover it?

It does not fit in my head that there is no life beyond Earth

R. This observatory has been unique in the history of science. Not only was it the largest radio telescope in the world, it was highly versatile. Its original antenna was complemented by many others that made it the most powerful tool not only in radio astronomy, but also to study our own atmosphere, the ionosphere, and also as a huge radar in support of NASA’s planetary defense office. The censuses discovered potentially dangerous asteroids and Arecibo pointed with its radar and allowed to calculate the orbit with great precision. We knew if they were dangerous and when the next approaches to our planet were going to be.

P. So are we a little more blind to dangerous asteroids?

R. We have become much more blind. Right now we practically only have the antenna Goldstone, from NASA, which is much smaller. We can only characterize the largest and closest objects. All the asteroids that could catastrophically destroy the Earth are already mapped, but there are many more that are not and that could destroy entire cities.

P. Do you believe that there is life beyond Earth? If so, where are we most likely to find it?

R. There is no proof, but I can’t imagine that there isn’t. There are so many stars, so many planetary systems that there must be life in one of them. Another thing is that we are able to discover it. That is why we must continue collecting data, observing, investing to search other stars for those signals that we think originated life on Earth. We must find discs with materials similar to ours. In addition, there is the project of technological indications, which is based on tracking the universe in case we are receiving an artificial signal, manufactured by a possible civilization

P. Do you think such signs can exist?

R. It is something interesting. We cannot close ourselves to that possibility.

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