Did you know that there are planets that wander through space without orbiting a star? These rogue planets have been kicked out of their star systems by gravitational interactions with other planets and stars. The exact number of these rogue planets remains a mystery, but that may change soon.
A team of researchers from NASA’s Goddard Space Flight Center and Osaka University in Japan have found a way to estimate the number of rogue planets in the heart of the Milky Way. By analyzing data from the Microlensing Observations in Astrophysics (MOA) survey, they have determined how many more of these events we could expect to find with NASA’s upcoming Nancy Grace Roman Space Telescope.
Currently, there are only 70 known rogue planets, but the researchers believe that Roman could discover at least 400 Earth-mass rogues wandering through our galaxy.
Using gravity as a magnifying glass
Gravity has the power to bend spacetime, and this phenomenon is known as gravitational lensing. When a rogue planet passes in front of a distant star, the light from that star will pass through the curved space created by the planet’s mass, magnifying the brightness of the star. This gravitational microlensing effect helps scientists detect these elusive rogue planets.
Most rogue planets are small in size and not associated with a star, making them incredibly difficult to spot. However, gravitational microlensing can assist in their detection.
Rogue planets ranging from Mars mass to Earth mass will be the primary targets for the Roman telescope. As they pass in front of a star and bend spacetime, observations can be made to study these objects.
“Gravitational microlensing enables us to study a variety of objects with masses ranging from that of exoplanets to black holes,” the researchers said.
Lonely telescope seeks unattached planets
After its launch in 2027, the Roman telescope will search for rogue planets at the heart of the Milky Way. By using data from previous surveys, the research team has estimated that our galaxy is home to trillions of rogue planets, twenty times more than the number of stars.
Furthermore, the team predicts that there are at least six times more small rogue planets than planets with wide orbits in our galaxy’s center. These predicted rogues have masses between Mars and Earth.
If some planets of this mass have wide orbits, it suggests that they were once in orbit around stars but were thrown into space by intense gravitational interactions. Roman’s instruments are expected to detect more microlensing events and reveal these hidden planets.
For now, we can only imagine what might be lurking out there in the vastness of space.
Elizabeth Rayne is a creature who writes. Her work has appeared on SYFY WIRE, Space.com, Live Science, Grunge, Den of Geek, and Forbidden Futures. When not writing, she is either shapeshifting, drawing, or cosplaying as a character nobody has ever heard of. Follow her on Twitter @quothravenrayne.
NASA has just unveiled its first of a kind space telescope, the Roman Space Telescope (formerly the Wide Field Infrared Survey Telescope or WFIRST), set to be launched in the year 25. The launch of this incredibly ambitious telescope marks an important milestone in the space agency’s effort to discover an abundance of Earth-sized rogue planets, which could potentially be our home in the universe.
Once launched, Roman will be capable of capturing light from stars and galaxies located hundreds of millions of light years away. In contrast to other missions, the telescope will be especially designed to discern Earth-sized exoplanets in unique configurations and in long-term orbits, a field of study lacking in available data.
The telescope is estimated to find thousands of Earth-sized exoplanets from our own Milky Way galaxy. In an area about the size of our own Solar System, the telescope should be able to spot signs of exoplanets and clues about the origin of life, including possible evidence of water or molecules suitable for habitability. These data are vital in furthering research for humanity’s place in space.
In addition to discovering exoplanets, Roman will be able to measure the masses and compositions of planets, and determine their atmospheres at the same time. Through its sensitive optics, the telescope will be able to differentiate between Neptune-like planets and true super-Earths. Additionally, it will measure the distances between stars, enabling astrophysicists to learn more about the motions of stars within galaxies to assess their age.
NASA’s Roman Telescope will mark new heights in our space exploration and will enable us to learn more than ever before about the universe. Its discoveries could go a long way in informing us on our place in the universe, and whether or not there is any chance of finding a place to call home outside our planet.
