Photobombing exoplanets might thwart search for extraterrestrial life

Artist’s concept of Kepler-186f, an Earth-size exoplanet orbiting a red dwarf star in the constellation Cygnus.
Light from other exoplanets might confuse telescopes' search for life on other worlds. (Image credit: NASA/Tim Pyle)

It's frustrating when a stranger photobombs your family photo when you're on vacation. But when an exoplanet photobombs a space telescope's image of another exoplanet, it could actually ruin a scientist's research.

Yes, planetary photobombing is a thing — sort of. For those who don't know what photobomb means, Merriam-Webster defines it as "to move into the frame of a photograph as it is being taken as a joke or prank." The catch is that exoplanets aren't intentionally ruining a photograph, but they might inadvertently do so. 

A new study led by Prabal Saxena, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, indicates that a space telescope's image of a distant exoplanet (that is, a planet outside our solar system) might be contaminated by the light from another nearby exoplanet. That could potentially create errors when analyzing data — specifically the light spectra that could indicate an exoplanet's chemical composition.

Related: The 10 most Earth-like exoplanets 

"If you looked at Earth sitting next to Mars or Venus from a distant vantage point, then depending on when you observed them, you might think they're both the same object," Saxena said in a statement.

Because space telescopes have to "see" across extremely vast distances, light diffraction could likely cause two exoplanets to visually merge. That causes problems when scientists are attempting to analyze the spectra of an exoplanet in search of biosignatures, or signs of life. Cross-contamination from a different object could completely confuse the results.

Thus Saxena's team suggested several methods that could mitigate planetary photobombing, from using multiple telescopes to examine the same area to using a single telescope to observe the exoplanets over an extended period of time, which might help distinguish the object from the photobomber as they move in their orbits. 

The scientists, however, say that more research is required to solve the problem effectively.

The team's research was published in the Astrophysical Journal Letters on Aug. 11.

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Stefanie Waldek
Contributing writer contributing writer Stefanie Waldek is a self-taught space nerd and aviation geek who is passionate about all things spaceflight and astronomy. With a background in travel and design journalism, as well as a Bachelor of Arts degree from New York University, she specializes in the budding space tourism industry and Earth-based astrotourism. In her free time, you can find her watching rocket launches or looking up at the stars, wondering what is out there. Learn more about her work at