Hunting for life in alien atmospheres: Nasa probe Pandora to launch soon

Nasa's new space telescope Pandora is set to study at least 20 unknown exoplanets to analyse their atmospheres for haze, clouds, and water

Nasa has announced that its newest exoplanet mission Pandora is one step closer to launch with the completion of the spacecraft bus, which provides the structure, power, and other systems that will enable the mission to carry out its work.

 

“This is a huge milestone for us and keeps us on track for a launch in the fall,” said Elisa Quintana, Pandora’s principal investigator at NASA’s Goddard Space Flight Center. “The bus holds our instruments and handles navigation, data acquisition, and communication with Earth — it’s the brains of the spacecraft.”  

 

Pandora is a small satellite that will undertake a detailed study of at least 20 known planets orbiting distant stars in order to determine the composition of their atmospheres — especially the presence of hazes, clouds, and water. This data will establish a firm foundation for interpreting measurements by the space agency’s James Webb Space Telescope (JWST) and future missions that will search for habitable worlds, it said. 

 

 

“We see the presence of water as a critical aspect of habitability because water is essential to life as we know it,” says Goddard’s Ben Hord, a NASA Postdoctoral Program Fellow. 

 

“The problem with confirming its presence in exoplanet atmospheres is that variations in light from the host star can mask or mimic the signal of water. Separating these sources is where Pandora will shine.”

 

Funded by Nasa’s Astrophysics Pioneers program for small, ambitious missions, Pandora is a joint effort between Lawrence Livermore National Laboratory in California and Nasa Goddard.

 

The JWST may be a more sophisticated telescope, but according to Nasa scientists, Pandora’s near-infrared detector is actually a spare developed for the former, which right now is the observatory most sensitive to exoplanet atmospheres. 

 

Consequently, Pandora’s observations will improve Webb’s ability to separate the star’s signals from those of the planet’s atmosphere, enabling Webb to make more precise atmospheric measurements.

 

An exoplanet’s atmosphere is mapped the moment it passes in front of its host star, an event called a transit. Part of the star’s light skims the atmosphere before reaching earth. This interaction allows the light to interact with atmospheric substances, and their chemical fingerprints — dips in brightness at characteristic wavelengths — become imprinted in the light, says Nasa.

 

The space agency says the probe will use its all-aluminum, 45-centimeter-wide (17 inches) telescope to enable its detectors to capture each star’s visible brightness and near-infrared spectrum at the same time, while also obtaining the transiting planet’s near-infrared spectrum. This combined data will enable the science team to determine the properties of stellar surfaces and cleanly separate star and planetary signals.

 

“Over the course of its year-long prime mission, Pandora will observe at least 20 exoplanets 10 times, with each stare lasting a total of 24 hours. Each observation will include a transit, which is when the mission will capture the planet’s spectrum,” Nasa said in a blog published on its website.