James Webb Telescope's Mission to Unravel the Mysteries of TOI-1075 b

Artist's conception of TRAPPIST-1 e, a potentially habitable exoplanet that orbits a nearby star.

Credits: NASA

April 29, 2023

The James Webb Space Telescope, launched in December 2021, is poised to make groundbreaking discoveries about the universe. One of its main objectives is to observe exoplanets, planets that orbit stars beyond our solar system. One such exoplanet is TOI-1075 b, which has recently been identified as one of the most massive super-Earths discovered so far. Let’s take a closer look at this fascinating planet and what we can expect from the James Webb Telescope's observations.

TOI-1075 b is nearly 10 times the mass of Earth and orbits a small, red-orange star about 200 light-years away. Its year, or the time it takes to orbit its star once, takes only 14 ½ hours, making it one of the fastest-orbiting exoplanets discovered so far. Its orbit is so close to its star that its surface temperature is estimated to be a scorching 1,922 degrees Fahrenheit (1,050 Celsius). In other words, the planet is incredibly hot and its surface could be molten lava.

Despite the extreme conditions on TOI-1075 b, its study is important for scientists looking to understand how rocky planets like Earth form. Super-Earths, which are up to twice as large as Earth, are among the most common planets in our galaxy. However, they are shrouded in mystery as we have nothing like them in our own solar system. Scientists create computer models based on confirmed exoplanets to understand how various planet types form, what they are made of, and what kinds of atmospheres they might possess. Studying TOI-1075 b can yield new insights into the formation of these rocky planets and help scientists fine-tune their models.

Most super-Earths of TOI-1075 b's size would be expected to have a fairly thick atmosphere of hydrogen and helium, but the planet’s dense composition and scorching orbit make such an atmosphere unlikely. This makes TOI-1075 b a “keystone planet” – among only a few others so far with precise enough measurements of size and mass to help scientists fine-tune their models of planet formation. By studying its properties, scientists can predict what kinds of atmospheres super-Earths and other planet types possess or whether they have atmospheres at all.

The discovery of TOI-1075 b's hefty mass was announced by an international science team led by Zahra Essack of the Massachusetts Institute of Technology. The planet was discovered using the Transiting Exoplanet Survey Satellite (TESS), which revealed its diameter. More recent follow-up observations with ground-based instruments determined the planet’s mass. Its mass has been identified as nearly ten times that of Earth, making it a true “Hulk.” Standing on its surface would cause a significant weight gain, with a person weighing about three times their weight on Earth.

The James Webb Space Telescope is expected to provide vital information about TOI-1075 b's composition and atmosphere, as well as the temperatures and conditions on its surface. The telescope’s advanced instruments can detect the composition of exoplanet atmospheres by analyzing the light that passes through them as they transit in front of their stars. This method is called transit spectroscopy and is one of the key techniques the telescope will use to study exoplanets.

TOI-1075 b is a fascinating exoplanet that could provide valuable insights into how rocky planets like Earth form. Its extreme conditions make it a challenging target for study, but its properties make it a keystone planet that can help scientists fine-tune their models of planet formation. The James Webb Space Telescope’s advanced instruments are expected to provide groundbreaking observations of this planet, furthering our understanding of the universe and its many mysteries.