Astronomers keep discovering alien planets they don’t understand. Recently, they found a massive planet around a small star named GJ 3512. According to their theories, it shouldn’t exist. It is too large.
The Old View
A few years ago, astronomers thought that they knew how planets form. A solar system starts with a giant cloud of gas and dust in space that is pulled together by gravity. As the cloud is compressed, the temperature increases. Finally, it is hot and compressed enough to ignite a nuclear reaction, and a star is born.
There is still much dust and gas remaining around the newborn star. These then clump together to become planets. The heaviest elements, like iron, band together closest to the new sun and become solid planets like our Earth, or our neighbors Mercury, Venus, and Mars. Further out, they become fluffy giant gas balls like Jupiter, Saturn, Uranus, or Neptune.
A New Frontier
Scientists believed they understood how planets form until they started observing other solar systems. The planets that revolve around other stars are called exoplanets. The first one was discovered in 1992. Before then, many scientists believed that such objects were quite rare. Now we know that they are common. As of 2019, more than 3700 exoplanets have been discovered.
The recently discovered gas ball planet orbits a star that is 30 lightyears from Earth. To understand how far that is, you can imagine that the distance from Earth to the sun is one yard. Then, the distance to GJ 3512 would be like flying from Los Angeles to New York.
While it is exciting to discover something completely unexpected, it is also humbling and a sign that our understanding of the universe is not as complete as we imagined. Whenever you hear scientists say they are surprised by a finding, it is an implied admission that their theories were wrong or inadequate. Discovering exoplanets has led us to understand that we still have much to learn.
It is even more exciting that many of the exoplanets are similar to Earth in size, and some of them orbit stars that resemble our own sun. They may be habitable for humans. In 2017, a team of researchers at the University of Geneva discovered an Earth-like exoplanet around the red dwarf Ross 128. It is only 11 lightyears away!
This is still a significant distance, but if you are a teenager today, you may live to see the day when a human-made spacecraft visits this planet. If we are lucky, it may be a place where future generations of explorers can live and colonize.